4101:8-24-01 Fuel gas.

[Comment: When a reference is made within this rule to a federal statutory provision, an industry consensus standard, or any other technical publication, the specific date and title of the publication as well as the name and address of the promulgating agency are listed in rule 4101:8-44-01 of the Administrative Code. The application of the referenced standards shall be limited and as prescribed in section 102.5 of rule 4101:8-1-01 of the Administrative Code.]

SECTION 2401

GENERAL

2401.1 Application. This chapter covers those fuel gas piping systems, fuel-gas appliances and related accessories, venting systems and combustion air configurations most commonly encountered in the construction of one-, two-, and three-family dwellings and structures regulated by this code.

Coverage of piping systems shall extend from the point of delivery to the outlet of the appliance shutoff valves (see definition of "Point of delivery"). Piping systems requirements shall include design, materials, components, fabrication, assembly, installation, testing, inspection, operation and maintenance. Requirements for gas appliances and related accessories shall include installation, combustion and ventilation air and venting and connections to piping systems.

The omission from this chapter of any material or method of installation provided for in the "International Fuel Gas Code" shall not be construed as prohibiting the use of such material or method of installation. Fuel-gas piping systems, fuel-gas appliances and related accessories, venting systems and combustion air configurations not specifically covered in these chapters shall comply with the applicable provisions of the "International Fuel Gas Code".

Gaseous hydrogen systems shall be regulated by Chapter 7 of the "International Fuel Gas Code".

This chapter shall not apply to the following:

1. Liquified natural gas (LNG) installations.

2. Temporary LP-gas piping for buildings under construction or renovation that is not to become part of the permanent piping system.

3. Except as provided in Section G2412.1.1, gas piping, meters, gas pressure regulators, and other appurtenances used by the serving gas supplier in the distribution of gas, other than undiluted LP-gas.

4. Portable LP-gas appliances and equipment of all types that is not connected to a fixed fuel piping system.

5. Portable fuel cell appliances that are neither connected to a fixed piping system nor interconnected to a power grid.

6. Installation of hydrogen gas, LP-gas and compressed natural gas (CNG) systems on vehicles.

7.Existing fuel-gas piping systems, fuel-gas appliances and related accessories provided no serious hazard exists.

SECTION 2402

GENERAL

2402.1 Scope. Unless otherwise expressly stated, the following words and terms shall, for the purposes of this chapter, have the meanings indicated in this chapter.

2402.2 Interchangeability. Words used in the present tense include the future; words in the masculine gender include the feminine and neuter; the singular number includes the plural and the plural, the singular.

2402.3 Terms defined in other codes. Where terms are not defined in this code and are defined in the "Ohio Building Code", fire code, mechanical code or plumbing code, such terms shall have meanings ascribed to them as in those codes.

SECTION 2403

GENERAL DEFINITIONS

AIR CONDITIONING, GAS FIRED. A gas-burning, automatically operated appliance for supplying cooled and/or dehumidified air or chilled liquid.

AIR, EXHAUST. Air being removed from any space or piece of equipment or appliance and conveyed directly to the atmosphere by means of openings or ducts.

AIR-HANDLING UNIT. A blower or fan used for the purpose of distributing supply air to a room, space or area.

AIR, MAKEUP. Air that is provided to replace air being exhausted.

ALTERATION. The construction or renovation to an existing structure other than repair or addition

ALTERATION. A change in a system that involves an extension, addition or change to the arrangement, type or purpose of the existing installation.

ANODELESS RISER. A transition assembly in which plastic piping is installed and terminated above ground outside of a building.

APPLIANCE. Any apparatus or device that uses gas as a fuel or raw material to produce light, heat, power, refrigeration or air conditioning.

APPLIANCE, AUTOMATICALLY CONTROLLED. Appliances equipped with an automatic burner ignition and safety shut-off device and other automatic devices, which accomplish complete turn-on and shut-off of the gas to the main burner or burners, and graduate the gas supply to the burner or burners, but do not affect complete shut-off of the gas.

APPLIANCE, FAN-ASSISTED COMBUSTION. An appliance equipped with an integral mechanical means to either draw or force products of combustion through the combustion chamber or heat exchanger.

APPLIANCE, UNVENTED. An appliance designed or installed in such a manner that the products of combustion are not conveyed by a vent or chimney directly to the outside atmosphere.

APPLIANCE, VENTED. An appliance designed and installed in such a manner that all of the products of combustion are conveyed directly from the appliance to the outside atmosphere through an approved chimney or vent system.

APPROVED. Refers to approval by the building official as the result of review, investigation, inspection and testing in accordance with the provisions of this code.

ATMOSPHERIC PRESSURE. The pressure of the weight of air and water vapor on the surface of the earth, approximately 14.7 pounds per square inch (psia) (101 kPa absolute) at sea level.

AUTOMATIC IGNITION. Ignition of gas at the burner(s) when the gas controlling device is turned on, including reignition if the flames on the burner(s) have been extinguished by means other than by the closing of the gas controlling device.

BAROMETRIC DRAFT REGULATOR. A balanced damper device attached to a chimney, vent connector, breeching or flue gas manifold to protect combustion appliances by controlling chimney draft. A double-acting barometric draft regulator is one whose balancing damper is free to move in either direction to protect combustion appliances from both excessive draft and backdraft.

BOILER, LOW-PRESSURE. A steam boiler operating at pressures not exceeding fifteen psig, or a hot water heating boiler operating at pressures not exceeding one hundred sixty psig or temperatures not exceeding two hundred fifty degrees.

Hot water heating boiler. A boiler in which no steam is generated, from which hot water is circulated for heating purposes and then returned to the boiler, and that operates at water pressures not exceeding 160 psig (1100 kPa gauge) and at water temperatures not exceeding 250°F (121°C) at or near the boiler outlet.

Hot water supply boiler. A boiler, completely filled with water, which furnishes hot water to be used externally to itself, and that operates at water pressures not exceeding 160 psig (1100 kPa gauge) and at water temperatures not exceeding 250°F (121°C) at or near the boiler outlet.

Steam heating boiler. A boiler in which steam is generated and that operates at a steam pressure not exceeding 15 psig (100 kPa gauge).

BONDING JUMPER. A conductor installed to electrically connect metallic gas piping to the grounding electrode system.

BRAZING. A metal joining process wherein coalescence is produced by the use of a nonferrous filler metal having a melting point above 1,000°F (538°C), but lower than that of the base metal being joined. The filler material is distributed between the closely fitted surfaces of the joint by capillary action.

BTU. Abbreviation for British thermal unit, which is the quantity of heat required to raise the temperature of 1 pound (454 g) of water 1°F ( 0.56 °C) (1 Btu = 1055 J).

BUILDING OFFICIAL. An individual who has received and maintains a certification of "Residential Building Official" in accordance with rules of the board of building standards.

BURNER. A device for the final conveyance of the gas, or a mixture of gas and air, to the combustion zone.

Induced-draft. A burner that depends on draft induced by a fan that is an integral part of the appliance and is located downstream from the burner.

Power. A burner in which gas, air or both are supplied at pressures exceeding, for gas, the line pressure, and for air, atmospheric pressure, with this added pressure being applied at the burner.

CHIMNEY. A primarily vertical structure containing one or more flues, for the purpose of carrying gaseous products of combustion and air from an appliance to the outside atmosphere.

Factory-built chimney. A listed and labeled chimney composed of factory-made components, assembled in the field in accordance with manufacturer's instructions and the conditions of the listing.

Masonry chimney. A field-constructed chimney composed of solid masonry units, bricks, stones or concrete.

CLEARANCE. The minimum distance through air measured between the heat-producing surface of the mechanical appliance, device or equipment and the surface of the combustible material or assembly.

CLOTHES DRYER. An appliance used to dry wet laundry by means of heated air.

Type 1. Factory-built package, multiple production. Primarily used in the family living environment. Usually the smallest unit physically and in function output.

CODE. The Residential Code of Ohio.

COMBUSTION. In the context of this code, refers to the rapid oxidation of fuel accompanied by the production of heat or heat and light.

COMBUSTION AIR. Air necessary for complete combustion of a fuel, including theoretical air and excess air.

CONDENSATE. The liquid that condenses from a gas (including flue gas) caused by a reduction in temperature or increase in pressure.

CONNECTOR, APPLIANCE (Fuel). Rigid metallic pipe and fittings, semirigid metallic tubing and fittings or a listed and labeled device that connects an appliance to the gas piping system.

CONNECTOR, CHIMNEY OR VENT. The pipe that connects an appliance to a chimney or vent.

CONTROL. A manual or automatic device designed to regulate the gas, air, water or electrical supply to, or operation of, a mechanical system.

CONVERSION BURNER. A unit consisting of a burner and its controls for installation in an appliance originally utilizing another fuel.

CUBIC FOOT. The amount of gas that occupies 1 cubic foot ( 0.02832 m3) when at a temperature of 60°F (16°C), saturated with water vapor and under a pressure equivalent to that of 30 inches of mercury (101 kPa).

DAMPER. A manually or automatically controlled device to regulate draft or the rate of flow of air or combustion gases.

DECORATIVE GAS APPLIANCE, VENTED. A vented appliance wherein the primary function lies in the aesthetic effect of the flames.

DECORATIVE GAS APPLIANCES FOR INSTALLATION IN VENTED FIREPLACES. A vented appliance designed for installation within the fire chamber of a vented fireplace, wherein the primary function lies in the aesthetic effect of the flames.

DEMAND. The maximum amount of gas input required per unit of time, usually expressed in cubic feet per hour, or Btu/h (1 Btu/h = 0.2931 W).

DESIGN FLOOD ELEVATION. The elevation of the "design flood," including wave height, relative to the datum specified on the community's legally designated flood hazard map.

DILUTION AIR. Air that is introduced into a draft hood and is mixed with the flue gases.

DIRECT-VENT APPLIANCES. Fuel-burning appliance with a sealed combustion system that draws all air for combustion from the outside atmosphere and discharges all flue gases to the outside atmosphere.

DRAFT. The pressure difference existing between the appliance or any component part and the atmosphere, that causes a continuous flow of air and products of combustion through the gas passages of the appliance to the atmosphere.

Mechanical or induced draft. The pressure difference created by the action of a fan, blower or ejector that is located between the appliance and the chimney or vent termination.

Natural draft. The pressure difference created by a vent or chimney because of its height, and the temperature difference between the flue gases and the atmosphere.

DRAFT HOOD. A nonadjustable device built into an appliance, or made as part of the vent connector from an appliance, that is designed to (1) provide for ready escape of the flue gases from the appliance in the event of no draft, backdraft, or stoppage beyond the draft hood, (2) prevent a backdraft from entering the appliance, and (3) neutralize the effect of stack action of the chimney or gas vent upon operation of the appliance.

DRAFT REGULATOR. A device that functions to maintain a desired draft in the appliance by automatically reducing the draft to the desired value.

DRIP. The container placed at a low point in a system of piping to collect condensate and from which the condensate is removable.

DUCT FURNACE. A warm-air furnace normally installed in an air-distribution duct to supply warm air for heating. This definition shall apply only to a warm-air heating appliance that depends for air circulation on a blower not furnished as part of the furnace.

DWELLING UNIT. A single unit providing complete, independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking and sanitation. . The unit may include any accessory space intended for the exclusive use of the occupants of an individual dwelling unit such as a private garage, greenhouse, etc.

EQUIPMENT (OR FIXTURE). Any plumbing, heating, electrical, ventilating, air conditioning, refrigerating and fire protection devices and components of systems other than appliances, and elevators, dumb waiters, and other mechanical facilities or installations that are related to building services.

EXTERIOR MASONRY CHIMNEYS. Masonry chimneys exposed to the outdoors on one or more sides below the roof line.

FIREPLACE. A fire chamber and hearth constructed of noncombustible material for use with solid fuels and provided with a chimney.

Masonry fireplace. A field-constructed fireplace composed of solid masonry units, bricks, stones or concrete.

Factory-built fireplace. A fireplace composed of listed factory-built components assembled in accordance with the terms of listing to form the completed fireplace.

FLAME SAFEGUARD. A device that will automatically shut off the fuel supply to a main burner or group of burners when the means of ignition of such burners becomes inoperative, and when flame failure occurs on the burner or group of burners.

FLOOD HAZARD AREA. The greater of the following two areas:

1. The area within a floodplain subject to a 1 percent or greater chance of flooding in any given year.

2. This area designated as a flood hazard area on a community's flood hazard map, or otherwise legally designated.

FLOOR FURNACE. A completely self-contained furnace suspended from the floor of the space being heated, taking air for combustion from outside such space and with means for observing flames and lighting the appliance from such space.

FLUE, APPLIANCE. The passage(s) within an appliance through which combustion products pass from the combustion chamber of the appliance to the draft hood inlet opening on an appliance equipped with a draft hood or to the outlet of the appliance on an appliance not equipped with a draft hood.

FLUE COLLAR. That portion of an appliance designed for the attachment of a draft hood, vent connector or venting system.

FLUE GASES. Products of combustion plus excess air in appliance flues or heat exchangers.

FLUE LINER (LINING). A system or material used to form the inside surface of a flue in a chimney or vent, for the purpose of protecting the surrounding structure from the effects of combustion products and for conveying combustion products without leakage to the atmosphere.

FUEL GAS. A natural gas, manufactured gas, liquefied petroleum gas or mixtures of these gases.

FUEL GAS UTILIZATION EQUIPMENT. See "Appliance."

FURNACE. A completely self-contained heating unit that is designed to supply heated air to spaces remote from or adjacent to the appliance location.

FURNACE, CENTRAL. A self-contained appliance for heating air by transfer of heat of combustion through metal to the air, and designed to supply heated air through ducts to spaces remote from or adjacent to the appliance location.

FURNACE PLENUM. An air compartment or chamber to which one or more ducts are connected and which forms part of an air distribution system.

GAS CONVENIENCE OUTLET. A permanently mounted, manually operated device that provides the means for connecting an appliance to, and disconnecting an appliance from, the gas supply piping. The device includes an integral, manually operated valve with a nondisplaceable valve member and is designed so that disconnection of an appliance only occurs when the manually operated valve is in the closed position.

GAS PIPING. An installation of pipe, valves or fittings installed on a premises or in a building and utilized to convey fuel gas.

HAZARDOUS LOCATION. Any location considered to be a fire hazard for flammable vapors, dust, combustible fibers or other highly combustible substances.

HOUSE PIPING. See "Piping system."

IGNITION PILOT. A pilot that operates during the lighting cycle and discontinues during main burner operation.

IGNITION SOURCE. A flame spark or hot surface capable of igniting flammable vapors or fumes. Such sources include appliance burners, burner ignitors and electrical switching devices.

INFRARED RADIANT HEATER. A heater which directs a substantial amount of its energy output in the form of infrared radiant energy into the area to be heated. Such heaters are of either the vented or unvented type.

JOINT, FLARED. A metal-to-metal compression joint in which a conical spread is made on the end of a tube that is compressed by a flare nut against a mating flare.

JOINT, MECHANICAL. A general form of gas-tight joints obtained by the joining of metal parts through a positive-holding mechanical construction, such as flanged joint, threaded joint, flared joint or compression joint.

JOINT, PLASTIC ADHESIVE. A joint made in thermoset plastic piping by the use of an adhesive substance which forms a continuous bond between the mating surfaces without dissolving either one of them.

LEAK CHECK. An operation performed on a gas piping system to verify that the system does not leak.

LIQUEFIED PETROLEUM GAS or LPG (LP-GAS). Liquefied petroleum gas composed predominately of propane, propylene, butanes or butylenes, or mixtures thereof that is gaseous under normal atmospheric conditions, but is capable of being liquefied under moderate pressure at normal temperatures.

LIVING SPACE. Space within a dwelling unit utilized for living, sleeping, eating, cooking, bathing, washing and sanitation purposes.

LOG LIGHTER, GAS-FIRED. A manually operated solid-fuel ignition appliance for installation in a vented solid-fuel-burning fireplace.

MAIN BURNER. A device or group of devices essentially forming an integral unit for the final conveyance of gas or a mixture of gas and air to the combustion zone, and on which combustion takes place to accomplish the function for which the appliance is designed.

METER. The instrument installed to measure the volume of gas delivered through it.

MODULATING. Modulating or throttling is the action of a control from its maximum to minimum position in either predetermined steps or increments of movement as caused by its actuating medium.

OFFSET (VENT). A combination of approved bends that make two changes in direction bringing one section of the vent out of line, but into a line parallel with the other section.

OUTLET. The point at which a gas-fired appliance connects to the gas piping system.

OXYGEN DEPLETION SAFETY SHUTOFF SYSTEM (ODS). A system designed to act to shut off the gas supply to the main and pilot burners if the oxygen in the surrounding atmosphere is reduced below a predetermined level.

PILOT. A small flame that is utilized to ignite the gas at the main burner or burners.

PIPING. Where used in this code, "piping" refers to either pipe or tubing, or both.

Pipe. A rigid conduit of iron, steel, copper, brass or plastic.

Tubing. Semirigid conduit of copper, aluminum, plastic or steel.

PIPING SYSTEM. All fuel piping, valves and fittings from the outlet of the point of delivery to the outlets of the appliance shutoff valves.

PLASTIC, THERMOPLASTIC. A plastic that is capable of being repeatedly softened by increase of temperature and hardened by decrease of temperature.

POINT OF DELIVERY. For natural gas systems, the point of delivery is the outlet of the service meter assembly or the outlet of the service regulator or service shutoff valve where a meter is not provided. Where a valve is provided at the outlet of the service meter assembly, such valve shall be considered to be downstream of the point of delivery. For undiluted liquefied petroleum gas systems, the point of delivery shall be considered to be the outlet of the first regulator that reduces pressure to 2 psig ( 13.8 kPa) or less.

PRESSURE DROP. The loss in pressure due to friction or obstruction in pipes, valves, fittings, regulators and burners.

PRESSURE TEST. An operation performed to verify the gas-tight integrity of gas piping following its installation or modification.

READY ACCESS (TO). That which enables a device, appliance or equipment to be directly reached, without requiring the removal or movement of any panel, door or similar obstruction. (See "Access.")

REGULATOR. A device for controlling and maintaining a uniform gas supply pressure, either pounds-to-inches water column (MP regulator) or inches-to-inches water column (appliance regulator).

REGULATOR, GAS APPLIANCE. A pressure regulator for controlling pressure to the manifold of the gas appliance.

REGULATOR, LINE GAS PRESSURE. A device placed in a gas line between the service pressure regulator and the appliance for controlling, maintaining or reducing the pressure in that portion of the piping system downstream of the device.

REGULATOR, MEDIUM-PRESSURE (MP Regulator). A line pressure regulator that reduces gas pressure from the range of greater than 0.5 psig ( 3.4 kPa) and less than or equal to 5 psig ( 34.5 kPa) to a lower pressure.

REGULATOR, PRESSURE. A device placed in a gas line for reducing, controlling and maintaining the pressure in that portion of the piping system downstream of the device.

REGULATOR, SERVICE PRESSURE. A device installed by the serving gas supplier to reduce and limit the service line gas pressure to delivery pressure.

RELIEF OPENING. The opening provided in a draft hood to permit the ready escape to the atmosphere of the flue products from the draft hood in the event of no draft, backdraft or stoppage beyond the draft hood, and to permit air into the draft hood in the event of a strong chimney updraft.

RELIEF VALVE (DEVICE). A safety valve designed to forestall the development of a dangerous condition by relieving either pressure, temperature or vacuum in the hot water supply system.

RELIEF VALVE, PRESSURE. An automatic valve which opens and closes a relief vent, depending on whether the pressure is above or below a predetermined value.

RELIEF VALVE, TEMPERATURE.

Manual reset type. A valve which automatically opens a relief vent at a predetermined temperature and which must be manually returned to the closed position.

Reseating or self-closing type. An automatic valve which opens and closes a relief vent, depending on whether the temperature is above or below a predetermined value.

RELIEF VALVE, VACUUM. A valve that automatically opens and closes a vent for relieving a vacuum within the hot water supply system, depending on whether the vacuum is above or below a predetermined value.

RISER, GAS. A vertical pipe supplying fuel gas.

ROOM HEATER, UNVENTED. See "Unvented room heater."

ROOM HEATER, VENTED. A free-standing gas-fired heating unit used for direct heating of the space in and adjacent to that in which the unit is located. (See also "Vented room heater.")

SAFETY SHUTOFF DEVICE. See "Flame safeguard."

SHAFT. An enclosed space extending through one or more stories of a building, connecting vertical openings in successive floors, or floors and the roof.

SPECIFIC GRAVITY. As applied to gas, specific gravity is the ratio of the weight of a given volume to that of the same volume of air, both measured under the same condition.

THERMOSTAT.

Electric switch type. A device that senses changes in temperature and controls electrically, by means of separate components, the flow of gas to the burner(s) to maintain selected temperatures.

Integral gas valve type. An automatic device, actuated by temperature changes, designed to control the gas supply to the burner(s) in order to maintain temperatures between predetermined limits, and in which the thermal actuating element is an integral part of the device.

1.Graduating thermostat. A thermostat in which the motion of the valve is approximately in direct proportion to the effective motion of the thermal element induced by temperature change.

2.Snap-acting thermostat. A thermostat in which the thermostatic valve travels instantly from the closed to the open position, and vice versa.

TRANSITION FITTINGS, PLASTIC TO STEEL. An adapter for joining plastic pipe to steel pipe. The purpose of this fitting is to provide a permanent, pressure-tight connection between two materials that cannot be joined directly one to another.

UNIT HEATER.

High-static pressure type. A self-contained, automatically controlled, vented appliance having integral means for circulation of air against 0.2 inch w.c. (50 Pa) or greater static pressure. Such appliance is equipped with provisions for attaching an outlet air duct and, where the appliance is for indoor installation remote from the space to be heated, is also equipped with provisions for attaching an inlet air duct.

Low-static pressure type. A self-contained, automatically controlled, vented appliance, intended for installation in the space to be heated without the use of ducts, having integral means for circulation of air. Such units are allowed to be equipped with louvers or face extensions made in accordance with the manufacturer's specifications.

UNVENTED ROOM HEATER. An unvented heating appliance designed for stationary installation and utilized to provide comfort heating. Such appliances provide radiant heat or convection heat by gravity or fan circulation directly from the heater and do not utilize ducts.

VALVE. A device used in piping to control the gas supply to any section of a system of piping or to an appliance.

Appliance shutoff. A valve located in the piping system, used to isolate individual appliances for purposes such as service or replacement.

Automatic. An automatic or semiautomatic device consisting essentially of a valve and an operator that control the gas supply to the burner(s) during operation of an appliance. The operator shall be actuated by application of gas pressure on a flexible diaphragm, by electrical means, by mechanical means or by other approved means.

Automatic gas shutoff. A valve used in conjunction with an automatic gas shutoff device to shut off the gas supply to a water heating system. It shall be constructed integrally with the gas shutoff device or shall be a separate assembly.

Individual main burner. A valve that controls the gas supply to an individual main burner.

Main burner control. A valve that controls the gas supply to the main burner manifold.

Manual main gas-control. A manually operated valve in the gas line for the purpose of completely turning on or shutting off the gas supply to the appliance, except to a pilot or pilots that have independent shutoff.

Manual reset. An automatic shutoff valve installed in the gas supply piping and set to shut off when unsafe conditions occur. The device remains closed until manually reopened.

Service shutoff. A valve, installed by the serving gas supplier between the service meter or source of supply and the customer piping system, to shut off the entire piping system.

VENT. A pipe or other conduit composed of factory-made components, containing a passageway for conveying combustion products and air to the atmosphere, listed and labeled for use with a specific type or class of appliance.

Special gas vent. A vent listed and labeled for use with listed Category II, III and IV gas appliances.

Type B vent. A vent listed and labeled for use with appliances with draft hoods and other Category I appliances that are listed for use with Type B vents.

Type BW vent. A vent listed and labeled for use with wall furnaces.

Type L vent. A vent listed and labeled for use with appliances that are listed for use with Type L or Type B vents.

VENT CONNECTOR. See "Connector."

VENT PIPING.

Breather. Piping run from a pressure-regulating device to the outdoors, designed to provide a reference to atmospheric pressure. If the device incorporates an integral pressure relief mechanism, a breather vent can also serve as a relief vent.

Relief. Piping run from a pressure-regulating or pressure-limiting device to the outdoors, designed to provide for the safe venting of gas in the event of excessive pressure in the gas piping system.

VENTED GAS APPLIANCE CATEGORIES. Appliances that are categorized for the purpose of vent selection are classified into the following four categories:

Category I. An appliance that operates with a nonpositive vent static pressure and with a vent gas temperature that avoids excessive condensate production in the vent.

Category II. An appliance that operates with a nonpositive vent static pressure and with a vent gas temperature that is capable of causing excessive condensate production in the vent.

Category III. An appliance that operates with a positive vent static pressure and with a vent gas temperature that avoids excessive condensate production in the vent.

Category IV. An appliance that operates with a positive vent static pressure and with a vent gas temperature that is capable of causing excessive condensate production in the vent.

VENTED ROOM HEATER. A vented self-contained, free-standing, nonrecessed appliance for furnishing warm air to the space in which it is installed, directly from the heater without duct connections.

VENTED WALL FURNACE. A self-contained vented appliance complete with grilles or equivalent, designed for incorporation in or permanent attachment to the structure of a building, mobile home or travel trailer, and furnishing heated air circulated by gravity or by a fan directly into the space to be heated through openings in the casing. This definition shall exclude floor furnaces, unit heaters and central furnaces as herein defined.

VENTING SYSTEM. A continuous open passageway from the flue collar or draft hood of an appliance to the outside atmosphere for the purpose of removing flue or vent gases. A venting system is usually composed of a vent or a chimney and vent connector, if used, assembled to form the open passageway.

WALL HEATER, UNVENTED TYPE. A room heater of the type designed for insertion in or attachment to a wall or partition. Such heater does not incorporate concealed venting arrangements in its construction and discharges all products of combustion through the front into the room being heated.

WATER HEATER. Any heating appliance or equipment that heats potable water and supplies such water to the potable hot water distribution system.

SECTION 2404

GENERAL

2404.1 Scope. This section shall govern the approval and installation of all equipment and appliances that comprise parts of the installations regulated by this code in accordance with Section 2401.

2404.2 Other fuels. The requirements for combustion and dilution air for gas-fired appliances shall be governed by Section 2407. The requirements for combustion and dilution air for appliances operating with fuels other than fuel gas shall be regulated by Chapter 17.

2404.3 Listed and labeled. Appliances regulated by this code shall be listed and labeled for the application in which they are used unless otherwise approved in accordance with Section 106.4 and 106.5. The approval of unlisted appliances in accordance with Section 106.4 and 106.5shall be based upon approved engineering evaluation.

2404.4 Vibration isolation. Where means for isolation of vibration of an appliance is installed, an approved means for support and restraint of that appliance shall be provided.

2404.5 Repair. Defective material or parts shall be replaced or repaired in such a manner so as to preserve the original approval or listing.

2404.6 Wind resistance. Appliances and supports that are exposed to wind shall be designed and installed to resist the wind pressures determined in accordance with this code.

2404.7 Flood hazard. For structures located in flood hazard areas, the appliance, equipment and system installations regulated by this code shall be located at or above the design flood elevation and shall comply with the flood-resistant construction requirements of Section 322.

Exception: The appliance, equipment and system installations regulated by this code are permitted to be located below the design flood elevation provided that they are designed and installed to prevent water from entering or accumulating within the components and to resist hydrostatic and hydrodynamic loads and stresses, including the effects of buoyancy, during the occurrence of flooding to the design flood elevation and shall comply with the flood-resistant construction requirements of Section R322.

2404.8 Seismic resistance. When earthquake loads are applicable in accordance with this code, the supports shall be designed and installed for the seismic forces in accordance with this code.

2404.9 Rodentproofing. Buildings or structures and the walls enclosing habitable or occupiable rooms and spaces in which persons live, sleep or work, or in which feed, food or foodstuffs are stored, prepared, processed, served or sold, shall be constructed to protect against the entry of rodents.

2404.10 Auxiliary drain pan. Category IV condensing appliances shall be provided with an auxiliary drain pan where damage to any building component will occur as a result of stoppage in the condensate drainage system. Such pan shall be installed in accordance with the applicable provisions of Section M1411.

Exception: An auxiliary drain pan shall not be required for appliances that automatically shut down operation in the event of a stoppage in the condensate drainage system.

SECTION 2405

STRUCTURAL SAFETY

2405.1 Structural safety. The building shall not be weakened by the installation of any gas piping. In the process of installing or repairing any gas piping, the finished floors, walls, ceilings, tile work or any other part of the building or premises which are required to be changed or replaced shall be left in a safe structural condition in accordance with the requirements of this code.

2405.2 Alterations to trusses. Truss members and components shall not be cut, drilled, notched, spliced or otherwise altered in any way without the written concurrence and approval of a registered design professional. Alterations resulting in the addition of loads to any member (e.g., HVAC equipment, water heaters) shall not be permitted without verification that the truss is capable of supporting such additional loading.

2405.3 Engineered wood products. Cuts, notches and holes bored in trusses, structural composite lumber, structural glued-laminated members and I-joists are prohibited except where permitted by the manufacturer's recommendations or where the effects of such alterations are specifically considered in the design of the member by a registered design professional.

SECTION 2406

APPLIANCE LOCATION

2406.1 General. Appliances shall be located as required by this section, specific requirements elsewhere in this code and the conditions of the equipment and appliance listing.

2406.2 Prohibited locations. Appliances shall not be located in sleeping rooms, bathrooms, toilet rooms, storage closets or surgical rooms, or in a space that opens only into such rooms or spaces, except where the installation complies with one of the following:

1. The appliance is a direct-vent appliance installed in accordance with the conditions of the listing and the manufacturer's instructions.

2. Vented room heaters, wall furnaces, vented decorative appliances, vented gas fireplaces, vented gas fireplace heaters and decorative appliances for installation in vented solid fuel-burning fireplaces are installed in rooms that meet the required volume criteria of Section 2407.5.

3. A single wall-mounted unvented room heater is installed in a bathroom and such unvented room heater is equipped as specified in Section 2445.6 and has an input rating not greater than 6,000 Btu/h ( 1.76 kW). The bathroom shall meet the required volume criteria of Section 2407.5.

4. A single wall-mounted unvented room heater is installed in a bedroom and such unvented room heater is equipped as specified in Section 2445.6 and has an input rating not greater than 10,000 Btu/h ( 2.93 kW). The bedroom shall meet the required volume criteria of Section 2407.5.

5. The appliance is installed in a room or space that opens only into a bedroom or bathroom, and such room or space is used for no other purpose and is provided with a solid weather-stripped door equipped with an approved self-closing device. All combustion air shall be taken directly from the outdoors in accordance with Section 2407.6.

2406.3 Outdoor locations. Appliances installed in outdoor locations shall be either listed for outdoor installation or provided with protection from outdoor environmental factors that influence the operability, durability and safety of the appliance.

SECTION 2407

COMBUSTION, VENTILATION AND DILUTION AIR

2407.1 General. Air for combustion, ventilation and dilution of flue gases for appliances installed in buildings shall be provided by application of one of the methods prescribed in Sections 2407.5 through 2407.9. Where the requirements of Section 2407.5 are not met, outdoor air shall be introduced in accordance with one of the methods prescribed in Sections 2407.6 through 2407.9. Direct-vent appliances, gas appliances of other than natural draft design and vented gas appliances other than Category I shall be provided with combustion, ventilation and dilution air in accordance with the appliance manufacturer's instructions.

Exception: Type 1 clothes dryers that are provided with makeup air in accordance with Section 2439.4.

2407.2 Appliance location. Appliances shall be located so as not to interfere with proper circulation of combustion, ventilation and dilution air.

2407.3 Draft hood/regulator location. Where used, a draft hood or a barometric draft regulator shall be installed in the same room or enclosure as the appliance served so as to prevent any difference in pressure between the hood or regulator and the combustion air supply.

2407.4 Makeup air provisions. Where exhaust fans, clothes dryers and kitchen ventilation systems interfere with the operation of appliances, makeup air shall be provided.

2407.5 Indoor combustion air. The required volume of indoor air shall be determined in accordance with Section 2407.5.1 or 2407.5.2, except that where the air infiltration rate is known to be less than 0.40 air changes per hour (ACH), Section 2407.5.2 shall be used. The total required volume shall be the sum of the required volume calculated for all appliances located within the space. Rooms communicating directly with the space in which the appliances are installed through openings not furnished with doors, and through combustion air openings sized and located in accordance with Section 2407.5.3, are considered to be part of the required volume.

2407.5.1 Standard method. The minimum required volume shall be 50 cubic feet per 1,000 Btu/h ( 4.8 m3/kW).

2407.5.2 Known air-infiltration-rate method. Where the air infiltration rate of a structure is known, the minimum required volume shall be determined as follows:

For appliances other than fan assisted, calculate volume using Equation 24-1.

image: oh/admin/2014/41018-24-01-1.png

For fan-assisted appliances, calculate volume using Equation 24-2.

image: oh/admin/2014/41018-24-01-2.png

where:

Iother = All appliances other than fan assisted (input in Btu/h).

Ifan = Fan-assisted appliance (input in Btu/h).

ACH = Air change per hour (percent of volume of space exchanged per hour, expressed as a decimal).

For purposes of this calculation, an infiltration rate greater than 0.60 ACH shall not be used in Equations 24-1 and 24-2.

2407.5.3 Indoor opening size and location. Openings used to connect indoor spaces shall be sized and located in accordance with Sections 2407.5.3.1 and 2407.5.3.2 (see Figure 2407.5.3).

2407.5.3.1 Combining spaces on the same story. Each opening shall have a minimum free area of 1 square inch per 1,000 Btu/h (2,200 mm2/kW) of the total input rating of all appliances in the space, but not less than 100 square inches ( 0.06 m2). One opening shall commence within 12 inches (305 mm) of the top and one opening shall commence within 12 inches (305 mm) of the bottom of the enclosure. The minimum dimension of air openings shall be not less than 3 inches (76 mm).

2407.5.3.2 Combining spaces in different stories. The volumes of spaces in different stories shall be considered as communicating spaces where such spaces are connected by one or more openings in doors or floors having a total minimum free area of 2 square inches per 1,000 Btu/h (4402 mm2/kW) of total input rating of all appliances.

2407.6 Outdoor combustion air. Outdoor combustion air shall be provided through opening(s) to the outdoors in accordance with Section 2407.6.1 or 2407.6.2. The minimum dimension of air openings shall be not less than 3 inches (76 mm).

2407.6.1 Two-permanent-openings method. Two permanent openings, one commencing within 12 inches (305 mm) of the top and one commencing within 12 inches (305 mm) of the bottom of the enclosure, shall be provided. The openings shall communicate directly, or by ducts, with the outdoors or spaces that freely communicate with the outdoors.

Where directly communicating with the outdoors, or where communicating with the outdoors through vertical ducts, each opening shall have a minimum free area of 1 square inch per 4,000 Btu/h (550 mm2/kW) of total input rating of all appliances in the enclosure [see Figures 2407.6.1(1) and 2407.6.1(2)].

Where communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of not less than 1 square inch per 2,000 Btu/h (1,100 mm2/kW) of total input rating of all appliances in the enclosure [see Figure 2407.6.1(3)].

image: oh/admin/2014/4101$8-24-01_ph_ff_n_ru_20120529_1333-1.jpg

2407.6.2 One-permanent-opening method. One permanent opening, commencing within 12 inches (305 mm) of the top of the enclosure, shall be provided. The appliance shall have clearances of at least 1 inch (25 mm) from the sides and back and 6 inches (152 mm) from the front of the appliance. The opening shall directly communicate with the outdoors or through a vertical or horizontal duct to the outdoors, or spaces that freely communicate with the outdoors (see Figure 2407.6.2) and shall have a minimum free area of 1 square inch per 3,000 Btu/h (734 mm2/kW) of the total input rating of all appliances located in the enclosure and not less than the sum of the areas of all vent connectors in the space.

2407.7 Combination indoor and outdoor combustion air. The use of a combination of indoor and outdoor combustion air shall be in accordance with Sections 2407.7.1 through 2407.7.3.

2407.7.1 Indoor openings. Where used, openings connecting the interior spaces shall comply with Section 2407.5.3.

2407.7.2 Outdoor opening location. Outdoor opening(s) shall be located in accordance with Section 2407.6.

2407.7.3 Outdoor opening(s) size. The outdoor opening(s) size shall be calculated in accordance with the following:

1. The ratio of interior spaces shall be the available volume of all communicating spaces divided by the required volume.

2. The outdoor size reduction factor shall be one minus the ratio of interior spaces.

3. The minimum size of outdoor opening(s) shall be the full size of outdoor opening(s) calculated in accordance with Section 2407.6, multiplied by the reduction factor. The minimum dimension of air openings shall be not less than 3 inches (76 mm).

2407.8 Engineered installations. Engineered combustion air installations shall provide an adequate supply of combustion, ventilation and dilution air and shall be approved.

2407.9 Mechanical combustion air supply. Where all combustion air is provided by a mechanical air supply system, the combustion air shall be supplied from the outdoors at a rate not less than 0.35 cubic feet per minute per 1,000 Btu/h ( 0.034 m3/min per kW) of total input rating of all appliances located within the space.

2407.9.1 Makeup air. Where exhaust fans are installed, makeup air shall be provided to replace the exhausted air.

2407.9.2 Appliance interlock. Each of the appliances served shall be interlocked with the mechanical air supply system to prevent main burner operation when the mechanical air supply system is not in operation.

image: oh/admin/2014/4101$8-24-01_ph_ff_n_ru_20120529_1333-2.jpg

image: oh/admin/2014/4101$8-24-01_ph_ff_n_ru_20120529_1333-3.jpg

2407.9.3 Combined combustion air and ventilation air system. Where combustion air is provided by the building's mechanical ventilation system, the system shall provide the specified combustion air rate in addition to the required ventilation air.

2407.10 Louvers and grilles. The required size of openings for combustion, ventilation and dilution air shall be based on the net free area of each opening. Where the free area through a design of louver, grille or screen is known, it shall be used in calculating the size opening required to provide the free area specified. Where the design and free area of louvers and grilles are not known, it shall be assumed that wood louvers will have 25-percent free area and metal louvers and grilles will have 75-percent free area. Screens shall have a mesh size not smaller than 1/4 inch ( 6.4 mm). Nonmotorized louvers and grilles shall be fixed in the open position. Motorized louvers shall be interlocked with the appliance so that they are proven to be in the full open position prior to main burner ignition and during main burner operation. Means shall be provided to prevent the main burner from igniting if the louvers fail to open during burner start-up and to shut down the main burner if the louvers close during operation.

2407.11 Combustion air ducts. Combustion air ducts shall comply with all of the following:

1. Ducts shall be constructed of galvanized steel complying with Chapter 16 or of a material having equivalent corrosion resistance, strength and rigidity.

Exception: Within dwellings units, unobstructed stud and joist spaces shall not be prohibited from conveying combustion air, provided that not more than one required fireblock is removed.

2. Ducts shall terminate in an unobstructed space allowing free movement of combustion air to the appliances.

3. Ducts shall serve a single enclosure.

4. Ducts shall not serve both upper and lower combustion air openings where both such openings are used. The separation between ducts serving upper and lower combustion air openings shall be maintained to the source of combustion air.

5. Ducts shall not be screened where terminating in an attic space.

6. Horizontal upper combustion air ducts shall not slope downward toward the source of combustion air.

7. The remaining space surrounding a chimney liner, gas vent, special gas vent or plastic piping installed within a masonry, metal or factory-built chimney shall not be used to supply combustion air.

Exception: Direct-vent gas-fired appliances designed for installation in a solid fuel-burning fireplace where installed in accordance with the manufacturer's instructions.

8. Combustion air intake openings located on the exterior of a building shall have the lowest side of such openings located not less than 12 inches (305 mm) vertically from the adjoining finished ground level.

2407.12 Protection from fumes and gases. Where corrosive or flammable process fumes or gases, other than products of combustion, are present, means for the disposal of such fumes or gases shall be provided. Such fumes or gases include carbon monoxide, hydrogen sulfide, ammonia, chlorine and halogenated hydrocarbons.

In barbershops, beauty shops and other facilities where chemicals that generate corrosive or flammable products, such as aerosol sprays, are routinely used, nondirect vent-type appliances shall be located in a mechanical room separated or partitioned off from other areas with provisions for combustion air and dilution air from the outdoors. Direct-vent appliances shall be installed in accordance with the appliance manufacturer's installation instructions.

SECTION 2408

INSTALLATION

2408.1 General. Equipment and appliances shall be installed as required by the terms of their approval, in accordance with the conditions of listing, the manufacturer's instructions and this code. Manufacturers' installation instructions shall be available on the job site at the time of inspection. Where a code provision is less restrictive than the conditions of the listing of the equipment or appliance or the manufacturer's installation instructions, the conditions of the listing and the manufacturer's installation instructions shall apply.

Unlisted appliances approved in accordance with Section 2404.3 shall be limited to uses recommended by the manufacturer and shall be installed in accordance with the manufacturer's instructions, the provisions of this code and the requirements determined by the building official.

2408.2 Elevation of ignition source. Equipment and appliances having an ignition source shall be elevated such that the source of ignition is not less than 18 inches (457 mm) above the floor in hazardous locations and public garages, private garages, repair garages, motor fuel-dispensing facilities and parking garages. For the purpose of this section, rooms or spaces that are not part of the living space of a dwelling unit and that communicate directly with a private garage through openings shall be considered to be part of the private garage.

Exception: Elevation of the ignition source is not required for appliances that are listed as flammable vapor ignition resistant.

2408.2.1 Installation in residential garages. In residential garages where appliances are installed in a separate, enclosed space having access only from outside of the garage, such appliances shall be permitted to be installed at floor level, provided that the required combustion air is taken from the exterior of the garage.

2408.3 Private garages. Appliances located in private garages shall be installed with a minimum clearance of 6 feet (1829 mm) above the floor.

Exception: The requirements of this section shall not apply where the appliances are protected from motor vehicle impact and installed in accordance with Section 2408.2.

2408.4 Clearances from grade. Equipment and appliances installed at grade level shall be supported on a level concrete slab or other approved material extending not less than 3 inches (76 mm) above adjoining grade or shall be suspended not less than 6 inches (152 mm) above adjoining grade. Such supports shall be installed in accordance with the manufacturer's installation instructions.

2408.5 Clearances to combustible construction. Heat-producing equipment and appliances shall be installed to maintain the required clearances to combustible construction as specified in the listing and manufacturer's instructions. Such clearances shall be reduced only in accordance with Section 2409. Clearances to combustibles shall include such considerations as door swing, drawer pull, overhead projections or shelving and window swing. Devices, such as door stops or limits and closers, shall not be used to provide the required clearances.

2408.6 Avoid strain on gas piping. Appliances shall be supported and connected to the piping so as not to exert undue strain on the connections.

SECTION 2409

CLEARANCE REDUCTION

2409.1 Scope. This section shall govern the reduction in required clearances to combustible materials and combustible assemblies for chimneys, vents, appliances, devices and equipment.

2409.2 Reduction table. The allowable clearance reduction shall be based on one of the methods specified in Table 2409.2 or shall utilize an assembly listed for such application. Where required clearances are not listed in Table 2409.2, the reduced clearances shall be determined by linear interpolation between the distances listed in the table. Reduced clearances shall not be derived by extrapolation below the range of the table. The reduction of the required clearances to combustibles for listed and labeled appliances and equipment shall be in accordance with the requirements of this section except that such clearances shall not be reduced where reduction is specifically prohibited by the terms of the appliance or equipment listing [see Figures 2409.2(1), 2409.2(2) and 2409.2(3) ].

2409.3 Clearances for indoor air-conditioning appliances. Clearance requirements for indoor air-conditioning appliances shall comply with Sections 2409.3.1 through 2409.3.5.

2409.3.1 Appliances installed in rooms that are large in comparison with the size of the appliances. Air-conditioning appliances installed in rooms that are large in comparison with the size of the appliance shall be installed with

image: oh/admin/2014/4101$8-24-01_ph_ff_n_ru_20120529_1333-4.jpg

NOTES:

"A" equals the clearance with no protection.

"B" equals the reduced clearance permitted in accordance with Table 2409.2. The protection applied to the construction using combustible material shall extend far enough in each direction to make "C" equal to "A."

For SI: 1 inch = 25.4 mm.

FIGURE 2409.2(1)

EXTENT OF PROTECTION NECESSARY TO REDUCE CLEARANCES FROM GAS EQUIPMENT OR VENT CONNECTORS

image: oh/admin/2014/4101$8-24-01_ph_ff_n_ru_20120529_1333-5.jpg

2409.3.2 Appliances installed in rooms that are not large in comparison with the size of the appliances. Air-conditioning appliances installed in rooms that are not large in comparison with the size of the appliance, such as alcoves and closets, shall be listed for such installations and installed in accordance with the manufacturer's instructions. Listed clearances shall not be reduced by the protection methods described in Table 2409.2, regardless of whether the enclosure is of combustible or noncombustible material.

2409.3.3 Clearance reduction. Air-conditioning appliances installed in rooms that are large in comparison with the size of the appliance shall be permitted to be installed with reduced clearances to combustible material, provided that the combustible material or appliance is protected as described in Table 2409.2.

2409.3.4 Plenum clearances. Where the furnace plenum is adjacent to plaster on metal lath or noncombustible material attached to combustible material, the clearance shall be measured to the surface of the plaster or other noncombustible finish where the clearance specified is 2 inches (51 mm) or less.

2409.3.5 Clearance from supply ducts. Air-conditioning appliances shall have the clearance from supply ducts within 3 feet (914 mm) of the furnace plenum be not less than that specified from the furnace plenum. Clearance is not necessary beyond this distance.

2409.4 Central heating boilers and furnaces. Clearance requirements for central-heating boilers and furnaces shall comply with Sections 2409.4.1 through 2409.4.6. The clearance to these appliances shall not interfere with combustion air; draft hood clearance and relief; and accessibility for servicing.

2409.4.1 Appliances installed in rooms that are large in comparison with the size of the appliances. Central-heating furnaces and low-pressure boilers installed in rooms large in comparison with the size of the appliance shall be installed with clearances in accordance with the manufacturer's instructions.

2409.4.2 Appliances installed in rooms that are not large in comparison with the size of the appliances. Central-heating furnaces and low-pressure boilers installed in rooms that are not large in comparison with the size of the appliance, such as alcoves and closets, shall be listed for such installations. Listed clearances shall not be reduced by the protection methods described in Table 2409.2 and illustrated in Figures 2409.2(1) through 2409.2(3), regardless of whether the enclosure is of combustible or noncombustible material.

2409.4.3 Clearance reduction. Central heating furnaces and low-pressure boilers installed in rooms that are large in comparison with the size of the appliance shall be permitted to be installed with reduced clearances to combustible material provided the combustible material or equipment is protected as described in Table 2409.2.

2409.4.4 Plenum clearances. Where the furnace plenum is adjacent to plaster on metal lath or noncombustible material attached to combustible material, the clearance shall be measured to the surface of the plaster or other noncombustible finish where the clearance specified is 2 inches (51 mm) or less.

2409.4.5 Clearance from supply ducts. Central-heating furnaces shall have the clearance from supply ducts within 3 feet (914 mm) of the furnace plenum be not less than that specified from the furnace plenum. No clearance is necessary beyond this distance.

2409.4.6 Clearance for servicing appliances. Front clearance shall be sufficient for servicing the burner and the furnace or boiler.

SECTION 2410

ELECTRICAL

2410.1 Grounding. Gas piping shall not be used as a grounding electrode.

2410.2 Connections. Electrical connections between appliances and the building wiring, including the grounding of the appliances, shall conform to NFPA 70.

SECTION 2411

ELECTRICAL BONDING

2411.1 Pipe and tubing other than CSST. Each above-ground portion of a gas piping system other than corrugated stainless steel tubing (CSST), that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping, other than CSST, shall be considered to be bonded where it is connected to appliances that are connected to the equipment grounding conductor of the circuit supplying that appliance.

2411.1.1 CSST. Corrugated stainless steel tubing (CSST) gas piping systems shall be bonded to the electrical service grounding electrode system at the point where the gas service enters the building. The bonding jumper shall be not smaller than 6 AWG copper wire or equivalent.

TABLE 2409.2a through k

REDUCTION OF CLEARANCES WITH SPECIFIED FORMS OF PROTECTION

TYPE OF PROTECTION APPLIED TO AND COVERING ALL SURFACESOF COMBUSTIBLE MATERIALWITHIN THE DISTANCE SPECIFIEDAS THE REQUIRED CLEARANCEWITH NO PROTECTION [see Figures2409.2(1), 2409.2(2), and 2409.2(3) ] WHERE THE REQUIRED CLEARANCE WITH NO PROTECTION FROM APPLIANCE, VENT CONNECTOR, OR SINGLE-WALL METAL PIPE IS: (inches)
36 18 12 9 6
Allowable clearances with specified protection (inches)
Use Column 1 for clearances above appliance or horizontal connector. Use Column 2 for clearances from appliance, vertical connector and single-wall metal pipe.
Above Col. 1 Sides and rear Col. 2 Above Col. 1 Sides and rear Col. 2 Above Col. 1 Sides and rear Col. 2 Above Col. 1 Sides and rear Col. 2 Above Col. 1 Sides and rear Col. 2
1. 31/2-inch-thick masonry wall without ventilated airspace - 24 - 12 - 9 - 6 - 5
2. 1/2-inch insulation board over 1-inch glass fiber or mineral wool batts 24 18 12 9 9 6 6 5 4 3
3. 0.024 -inch (nominal 24 gage) sheet metal over 1-inch glass fiber or mineral wool batts reinforced with wire on rear face with ventilated airspace 18 12 9 6 6 4 5 3 3 3
4. 31/2-inch-thick masonry wall with ventilated airspace - 12 - 6 - 6 - 6 - 6
5. 0.024 -inch (nominal 24 gage) sheet metal with ventilated airspace 18 12 9 6 6 4 5 3 3 2
6. -inch-thick insulation board with ventilated airspace 18 12 9 6 6 4 5 3 3 3
7. 0.024 -inch (nominal 24 gage) sheet metal with ventilated airspace over 0.024 -inch (nominal 24 gage) sheet metal with ventilated airspace 18 12 9 6 6 4 5 3 3 3
8. 1-inch glass fiber or mineral wool batts sandwiched between two sheets 0.024 -inch (nominal 24 gage) sheet metal with ventilated airspace 18 12 9 6 6 4 5 3 3 3

For SI: 1 inch = 25.4 mm, °C = [(°F - 32)/ 1.8 ], 1 pound per cubic foot = 16.02 kg/m3, 1 Btu per inch per square foot per hour per °F = 0.144 W/m2 . . K.

a. Reduction of clearances from combustible materials shall not interfere with combustion air, draft hood clearance and relief, and accessibility of servicing.

b. All clearances shall be measured from the outer surface of the combustible material to the nearest point on the surface of the appliance, disregarding any intervening protection applied to the combustible material.

c. Spacers and ties shall be of noncombustible material. No spacer or tie shall be used directly opposite an appliance or connector.

d. For all clearance reduction systems using a ventilated airspace, adequate provision for air circulation shall be provided as described [see Figures 2409.2(2) and 2409.2(3) ].

e. There shall be at least 1 inch between clearance reduction systems and combustible walls and ceilings for reduction systems using ventilated airspace.

f. Where a wall protector is mounted on a single flat wall away from corners, it shall have a minimum 1-inch air gap. To provide air circulation, the bottom and top edges, or only the side and top edges, or all edges shall be left open.

g. Mineral wool batts (blanket or board) shall have a minimum density of 8 pounds per cubic foot and a minimum melting point of 1500°F.

h. Insulation material used as part of a clearance reduction system shall have a thermal conductivity of 1.0 Btu per inch per square foot per hour per °F or less.

i. There shall be at least 1 inch between the appliance and the protector. In no case shall the clearance between the appliance and the combustible surface be reduced below that allowed in this table.

j. All clearances and thicknesses are minimum; larger clearances and thicknesses are acceptable.

k. Listed single-wall connectors shall be installed in accordance with the manufacturer's installation instructions.

SECTION 2412

GENERAL

2412.1 Scope. This section shall govern the design, installation, modification and maintenance of piping systems. The applicability of this code to piping systems extends from the point of delivery to the connections with the appliances and includes the design, materials, components, fabrication, assembly, installation, testing, inspection, operation and maintenance of such piping systems.

2412.1.1 Utility piping systems located within buildings. Utility service piping located within buildings shall be installed in accordance with the structural safety and fire protection provisions of this code.

2412.2 Liquefied petroleum gas storage. The storage system for liquefied petroleum gas shall be designed and installed in accordance with the fire code and NFPA 58.

2412.3 Modifications to existing systems. In modifying or adding to existing piping systems, sizes shall be maintained in accordance with this chapter.

2412.4 Additional appliances. Where an additional appliance is to be served, the existing piping shall be checked to determine if it has adequate capacity for all appliances served. If inadequate, the existing system shall be enlarged as required or separate piping of adequate capacity shall be provided.

2412.5 Identification. For other than steel pipe, exposed piping shall be identified by a yellow label marked "Gas" in black letters. The marking shall be spaced at intervals not exceeding 5 feet (1524 mm). The marking shall not be required on pipe located in the same room as the appliance served.

2412.6 Interconnections. Where two or more meters are installed on the same premises, but supply separate consumers, the piping systems shall not be interconnected on the outlet side of the meters.

2412.7 Piping meter identification. Piping from multiple meter installations shall be marked with an approved permanent identification by the installer so that the piping system supplied by each meter is readily identifiable.

2412.8 Minimum sizes. All pipe utilized for the installation, extension and alteration of any piping system shall be sized to supply the full number of outlets for the intended purpose and shall be sized in accordance with Section 2413.

SECTION 2413

PIPE SIZING

2413.1 General considerations. Piping systems shall be of such size and so installed as to provide a supply of gas sufficient to meet the maximum demand and supply gas to each appliance inlet at not less than the minimum supply pressure required by the appliance.

2413.2 Maximum gas demand. The volume of gas to be provided, in cubic feet per hour, shall be determined directly from the manufacturer's input ratings of the appliances served. Where an input rating is not indicated, the gas supplier, appliance manufacturer or a qualified agency shall be contacted, or the rating from Table 2413.2 shall be used for estimating the volume of gas to be supplied.

The total connected hourly load shall be used as the basis for pipe sizing, assuming that all appliances could be operating at full capacity simultaneously. Where a diversity of load can be established, pipe sizing shall be permitted to be based on such loads.

TABLE 2413.2

APPROXIMATE GAS INPUT FOR TYPICAL APPLIANCES

APPLIANCE INPUT BTU/H (Approx.)
Space Heating Units  
Hydronic boiler  
Single family 100,000
Multifamily, per unit 60,000
Warm-air furnace  
Single family 100,000
Multifamily, per unit 60,000
Space and Water Heating Units  
Hydronic boiler  
Single family 120,000
Multifamily, per unit 75,000
Water Heating Appliances  
Water heater, automatic instantaneous 142,800
Capacity at 2 gal./minute 285,000
Capacity at 4 gal./minute 428,400
Capacity at 6 gal./minute  
Water heater, automatic storage, 30- to 40-gal. tank 35,000
Water heater, automatic storage, 50-gal. tank 50,000
Water heater, domestic, circulating or side-arm 35,000
Cooking Appliances  
Built-in oven or broiler unit, domestic 25,000
Built-in top unit, domestic 40,000
Range, free-standing, domestic 65,000
Other Appliances  
Barbecue 40,000
Clothes dryer, Type 1 (domestic) 35,000
Gas fireplace, direct-vent 40,000
Gas light 2,500
Gas log 80,000
Refrigerator 3,000

For SI: 1 British thermal unit per hour = 0.293 W, 1 gallon = 3.785 L, 1 gallon per minute = 3.785 L/m.

2413.3 Sizing. Gas piping shall be sized in accordance with one of the following:

1. Pipe sizing tables or sizing equations in accordance with Section 2413.4.

2. The sizing tables included in a listed piping system's manufacturer's installation instructions.

3. Other approved engineering methods.

2413.4 Sizing tables and equations. Where Tables 2413.4(1) through 2413.4(21) are used to size piping or tubing, the pipe length shall be determined in accordance with Section 2413.4.1, 2413.4.2 or 2413.4.3.

Where Equations 24-3 and 24-4 are used to size piping or tubing, the pipe or tubing shall have smooth inside walls and the pipe length shall be determined in accordance with Section 2413.4.1, 2413.4.2 or 2413.4.3.

1. Low-pressure gas equation [Less than 1.5 pounds per square inch (psi) ( 10.3 kPa)]:

image: oh/admin/2014/4101$8-24-01_ph_ff_n_ru_20120529_1333-6.png

2. High-pressure gas equation [ 1.5 psi ( 10.3 kPa) and above]:

image: oh/admin/2014/4101$8-24-01_ph_ff_n_ru_20120529_1333-7.png

where:

D = Inside diameter of pipe, inches (mm).

Q = Input rate appliance(s), cubic feet per hour at 60°F (16°C) and 30-inch mercury column.

P1 = Upstream pressure, psia (P1 + 14.7 ).

P2 = Downstream pressure, psia (P2 + 14.7 ).

L = Equivalent length of pipe, feet.

[DELTA] H = Pressure drop, inch water column ( 27.7 inch water column = 1 psi).

TABLE 2413.4

CrAND Y VALUES FOR NATURAL GAS AND UNDILUTED PROPANE AT STANDARD CONDITIONS

GAS EQUATION FACTORS
Cr Y
Natural gas 0.6094 0.9992
Undiluted propane 1.2462 0.9910

For SI: 1 cubic foot = 0.028 m3, 1 foot = 305 mm, 1 inch water column = 0.249 kPa, 1 pound per square inch = 6.895 kPa, 1 British thermal unit per hour = 0.293 W.

2413.4.1 Longest length method. The pipe size of each section of gas piping shall be determined using the longest length of piping from the point of delivery to the most remote outlet and the load of the section.

2413.4.2 Branch length method. Pipe shall be sized as follows:

1. Pipe size of each section of the longest pipe run from the point of delivery to the most remote outlet shall be determined using the longest run of piping and the load of the section.

2. The pipe size of each section of branch piping not previously sized shall be determined using the length of piping from the point of delivery to the most remote outlet in each branch and the load of the section.

2413.4.3 Hybrid pressure. The pipe size for each section of higher pressure gas piping shall be determined using the longest length of piping from the point of delivery to the most remote line pressure regulator. The pipe size from the line pressure regulator to each outlet shall be determined using the length of piping from the regulator to the most remote outlet served by the regulator.

2413.5 Allowable pressure drop. The design pressure loss in any piping system under maximum probable flow conditions, from the point of delivery to the inlet connection of the appliance, shall be such that the supply pressure at the appliance is greater than or equal to the minimum pressure required by the appliance.

2413.6 Maximum design operating pressure. The maximum design operating pressure for piping systems located inside buildings shall not exceed 5 pounds per square inch gauge (psig) (34 kPa gauge) except where one or more of the following conditions are met:

1. The piping system is welded.

2. The piping is located in a ventilated chase or otherwise enclosed for protection against accidental gas accumulation.

3. The piping is a temporary installation for buildings under construction.

2413.6.1 Liquefied petroleum gas systems. LP-gas systems designed to operate below -5°F (-21°C) or with butane or a propane-butane mix shall be designed to either accommodate liquid LP-gas or prevent LP-gas vapor from condensing into a liquid.

TABLE 2413.4(1)

SCHEDULE 40 METALLIC PIPE

Gas Natural
Inlet Pressure Less than 2 psi
Pressure Drop 0.5 in. w.c.
Specific Gravity 0.60

PIPE SIZE (inch)
Nominal 1/2 3/4 1 11/4 11/2 2 21/2 3 4 5 6 8 10 12
Actual ID 0.622 0.824 1.049 1.380 1.610 2.067 2.469 3.068 4.026 5.047 6.065 7.981 10.020 11.938
Length (ft) Capacity in Cubic Feet of Gas per Hour
10 172 360 678 1,390 2,090 4,020 6,400 11,300 23,100 41,800 67,600 139,000 252,000 399,000
20 118 247 466 957 1,430 2,760 4,400 7,780 15,900 28,700 46,500 95,500 173,000 275,000
30 95 199 374 768 1,150 2,220 3,530 6,250 12,700 23,000 37,300 76,700 139,000 220,000
40 81 170 320 657 985 1,900 3,020 5,350 10,900 19,700 31,900 65,600 119,000 189,000
50 72 151 284 583 873 1,680 2,680 4,740 9,660 17,500 28,300 58,200 106,000 167,000
60 65 137 257 528 791 1,520 2,430 4,290 8,760 15,800 25,600 52,700 95,700 152,000
70 60 126 237 486 728 1,400 2,230 3,950 8,050 14,600 23,600 48,500 88,100 139,000
80 56 117 220 452 677 1,300 2,080 3,670 7,490 13,600 22,000 45,100 81,900 130,000
90 52 110 207 424 635 1,220 1,950 3,450 7,030 12,700 20,600 42,300 76,900 122,000
100 50 104 195 400 600 1,160 1,840 3,260 6,640 12,000 19,500 40,000 72,600 115,000
125 44 92 173 355 532 1,020 1,630 2,890 5,890 10,600 17,200 35,400 64,300 102,000
150 40 83 157 322 482 928 1,480 2,610 5,330 9,650 15,600 32,100 58,300 92,300
175 37 77 144 296 443 854 1,360 2,410 4,910 8,880 14,400 29,500 53,600 84,900
200 34 71 134 275 412 794 1,270 2,240 4,560 8,260 13,400 27,500 49,900 79,000
250 30 63 119 244 366 704 1,120 1,980 4,050 7,320 11,900 24,300 44,200 70,000
300 27 57 108 221 331 638 1,020 1,800 3,670 6,630 10,700 22,100 40,100 63,400
350 25 53 99 203 305 587 935 1,650 3,370 6,100 9,880 20,300 36,900 58,400
400 23 49 92 189 283 546 870 1,540 3,140 5,680 9,190 18,900 34,300 54,300
450 22 46 86 177 266 512 816 1,440 2,940 5,330 8,620 17,700 32,200 50,900
500 21 43 82 168 251 484 771 1,360 2,780 5,030 8,150 16,700 30,400 48,100
550 20 41 78 159 239 459 732 1,290 2,640 4,780 7,740 15,900 28,900 45,700
600 19 39 74 152 228 438 699 1,240 2,520 4,560 7,380 15,200 27,500 43,600
650 18 38 71 145 218 420 669 1,180 2,410 4,360 7,070 14,500 26,400 41,800
700 17 36 68 140 209 403 643 1,140 2,320 4,190 6,790 14,000 25,300 40,100
750 17 35 66 135 202 389 619 1,090 2,230 4,040 6,540 13,400 24,400 38,600
800 16 34 63 130 195 375 598 1,060 2,160 3,900 6,320 13,000 23,600 37,300
850 16 33 61 126 189 363 579 1,020 2,090 3,780 6,110 12,600 22,800 36,100
900 15 32 59 122 183 352 561 992 2,020 3,660 5,930 12,200 22,100 35,000
950 15 31 58 118 178 342 545 963 1,960 3,550 5,760 11,800 21,500 34,000
1,000 14 30 56 115 173 333 530 937 1,910 3,460 5,600 11,500 20,900 33,100
1,100 14 28 53 109 164 316 503 890 1,810 3,280 5,320 10,900 19,800 31,400
1,200 13 27 51 104 156 301 480 849 1,730 3,130 5,070 10,400 18,900 30,000
1,300 12 26 49 100 150 289 460 813 1,660 3,000 4,860 9,980 18,100 28,700
1,400 12 25 47 96 144 277 442 781 1,590 2,880 4,670 9,590 17,400 27,600
1,500 11 24 45 93 139 267 426 752 1,530 2,780 4,500 9,240 16,800 26,600
1,600 11 23 44 89 134 258 411 727 1,480 2,680 4,340 8,920 16,200 25,600
1,700 11 22 42 86 130 250 398 703 1,430 2,590 4,200 8,630 15,700 24,800
1,800 10 22 41 84 126 242 386 682 1,390 2,520 4,070 8,370 15,200 24,100
1,900 10 21 40 81 122 235 375 662 1,350 2,440 3,960 8,130 14,800 23,400
2,000 NA 20 39 79 119 229 364 644 1,310 2,380 3,850 7,910 14,400 22,700

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 NA means a flow of less than 10 cfh.

2 All table entries have been rounded to three significant digits.

TABLE 2413.4(2)

SCHEDULE 40 METAL LIC PIPE

Gas Natural
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 0.60

PIPE SIZE (inch)
Nominal 1/2 3/4 1 11/4 11/2 2 21/2 3 4
Actual ID 0.622 0.824 1.049 1.380 1.610 2.067 2.469 3.068 4.026
Length (ft) Capacity in Cubic Feet of Gas per Hour
10 1,510 3,040 5,560 11,400 17,100 32,900 52,500 92,800 189,000
20 1,070 2,150 3,930 8,070 12,100 23,300 37,100 65,600 134,000
30 869 1,760 3,210 6,590 9,880 19,000 30,300 53,600 109,000
40 753 1,520 2,780 5,710 8,550 16,500 26,300 46,400 94,700
50 673 1,360 2,490 5,110 7,650 14,700 23,500 41,500 84,700
60 615 1,240 2,270 4,660 6,980 13,500 21,400 37,900 77,300
70 569 1,150 2,100 4,320 6,470 12,500 19,900 35,100 71,600
80 532 1,080 1,970 4,040 6,050 11,700 18,600 32,800 67,000
90 502 1,010 1,850 3,810 5,700 11,000 17,500 30,900 63,100
100 462 934 1,710 3,510 5,260 10,100 16,100 28,500 58,200
125 414 836 1,530 3,140 4,700 9,060 14,400 25,500 52,100
150 372 751 1,370 2,820 4,220 8,130 13,000 22,900 46,700
175 344 695 1,270 2,601 3,910 7,530 12,000 21,200 43,300
200 318 642 1,170 2,410 3,610 6,960 11,100 19,600 40,000
250 279 583 1,040 2,140 3,210 6,180 9,850 17,400 35,500
300 253 528 945 1,940 2,910 5,600 8,920 15,800 32,200
350 232 486 869 1,790 2,670 5,150 8,210 14,500 29,600
400 216 452 809 1,660 2,490 4,790 7,640 13,500 27,500
450 203 424 759 1,560 2,330 4,500 7,170 12,700 25,800
500 192 401 717 1,470 2,210 4,250 6,770 12,000 24,400
550 182 381 681 1,400 2,090 4,030 6,430 11,400 23,200
600 174 363 650 1,330 2,000 3,850 6,130 10,800 22,100
650 166 348 622 1,280 1,910 3,680 5,870 10,400 21,200
700 160 334 598 1,230 1,840 3,540 5,640 9,970 20,300
750 154 322 576 1,180 1,770 3,410 5,440 9,610 19,600
800 149 311 556 1,140 1,710 3,290 5,250 9,280 18,900
850 144 301 538 1,100 1,650 3,190 5,080 8,980 18,300
900 139 292 522 1,070 1,600 3,090 4,930 8,710 17,800
950 135 283 507 1,040 1,560 3,000 4,780 8,460 17,200
1,000 132 275 493 1,010 1,520 2,920 4,650 8,220 16,800
1,100 125 262 468 960 1,440 2,770 4,420 7,810 15,900
1,200 119 250 446 917 1,370 2,640 4,220 7,450 15,200
1,300 114 239 427 878 1,320 2,530 4,040 7,140 14,600
1,400 110 230 411 843 1,260 2,430 3,880 6,860 14,000
1,500 106 221 396 812 1,220 2,340 3,740 6,600 13,500
1,600 102 214 382 784 1,180 2,260 3,610 6,380 13,000
1,700 99 207 370 759 1,140 2,190 3,490 6,170 12,600
1,800 96 200 358 736 1,100 2,120 3,390 5,980 12,200
1,900 93 195 348 715 1,070 2,060 3,290 5,810 11,900
2,000 91 189 339 695 1,040 2,010 3,200 5,650 11,500

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Note: All table entries have been rounded to three significant digits.

TABLE 2413.4(3)

SEMIRIGID COPPER TUBING

Gas Natural
Inlet Pressure Less than 2 psi
Pressure Drop 0.5 in. w.c.
Specific Gravity 0.60

TUBE SIZE (inch)
Nominal K & L 1/4 3/8 1/2 5/8 3/4 1 11/4 11/2 2
ACR 3/8 1/2 5/8 3/4 7/8 11/8 13/8 - -
Outside 0.375 0.500 0.625 0.750 0.875 1.125 1.375 1.625 2.125
Inside 0.305 0.402 0.527 0.652 0.745 0.995 1.245 1.481 1.959
Length (ft) Capacity in Cubic Feet of Gas per Hour
10 27 55 111 195 276 590 1,060 1,680 3,490
20 18 38 77 134 190 406 730 1,150 2,400
30 15 30 61 107 152 326 586 925 1,930
40 13 26 53 92 131 279 502 791 1,650
50 11 23 47 82 116 247 445 701 1,460
60 10 21 42 74 105 224 403 635 1,320
70 NA 19 39 74 68 96 206 371 585 1,220
80 NA 18 36 63 90 192 345 544 1,130
90 NA 17 34 59 84 180 324 510 1,060
100 NA 16 32 56 79 170 306 482 1,000
125 NA 14 28 50 70 151 271 427 890
150 NA 13 26 45 64 136 245 387 806
175 NA 12 24 41 59 125 226 356 742
200 NA 11 22 39 55 117 210 331 690
250 NA NA 20 34 48 103 186 294 612
300 NA NA 18 31 44 94 169 266 554
350 NA NA 16 28 40 86 155 245 510
400 NA NA 15 26 38 80 144 228 474
450 NA NA 14 25 35 75 135 214 445
500 NA NA 13 23 33 71 128 202 420
550 NA NA 13 22 32 68 122 192 399
600 NA NA 12 21 30 64 116 183 381
650 NA NA 12 20 29 62 111 175 365
700 NA NA 11 20 28 59 107 168 350
750 NA NA 11 19 27 57 103 162 338
800 NA NA 10 18 26 55 99 156 326
850 NA NA 10 18 25 53 96 151 315
900 NA NA NA 17 24 52 93 147 306
950 NA NA NA 17 24 50 90 143 297
1,000 NA NA NA 16 23 49 88 139 289
1,100 NA NA NA 15 22 46 84 132 274
1,200 NA NA NA 15 21 44 80 126 262
1,300 NA NA NA 14 20 42 76 120 251
1,400 NA NA NA 13 19 41 73 116 241
1,500 NA NA NA 13 18 39 71 111 232
1,600 NA NA NA 13 18 38 68 108 224
1,700 NA NA NA 12 17 37 66 104 217
1,800 NA NA NA 12 17 36 64 101 210
1,900 NA NA NA 11 16 35 62 98 204
2,000 NA NA NA 11 16 34 60 95 199

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.

2 NA means a flow of less than 10 cfh.

3 All table entries have been rounded to three significant digits.

TABLE 2413.4(4)

SEMIRIGID COPPER TUBING

Gas Natural
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 0.60

TUBE SIZE (inch)
Nominal K & L 1/4 3/8 1/2 5/8 3/4 1 11/4 11/2 2
ACR 3/8 1/2 5/8 3/4 7/8 11/8 13/8 - -
Outside 0.375 0.500 0.625 0.750 0.875 1.125 1.375 1.625 2.125
Inside 0.305 0.402 0.527 0.652 0.745 0.995 1.245 1.481 1.959
Length (ft) Capacity in Cubic Feet of Gas per Hour
10 245 506 1,030 1,800 2,550 5,450 9,820 15,500 32,200
20 169 348 708 1,240 1,760 3,750 6,750 10,600 22,200
30 135 279 568 993 1,410 3,010 5,420 8,550 17,800
40 116 239 486 850 1,210 2,580 4,640 7,310 15,200
50 103 212 431 754 1,070 2,280 4,110 6,480 13,500
60 93 192 391 683 969 2,070 3,730 5,870 12,200
70 86 177 359 628 891 1,900 3,430 5,400 11,300
80 80 164 334 584 829 1,770 3,190 5,030 10,500
90 75 154 314 548 778 1,660 2,990 4,720 9,820
100 71 146 296 518 735 1,570 2,830 4,450 9,280
125 63 129 263 459 651 1,390 2,500 3,950 8,220
150 57 117 238 416 590 1,260 2,270 3,580 7,450
175 52 108 219 383 543 1,160 2,090 3,290 6,850
200 49 100 204 356 505 1,080 1,940 3,060 6,380
250 43 89 181 315 448 956 1,720 2,710 5,650
300 39 80 164 286 406 866 1,560 2,460 5,120
350 36 74 150 263 373 797 1,430 2,260 4,710
400 33 69 140 245 347 741 1,330 2,100 4,380
450 31 65 131 230 326 696 1,250 1,970 4,110
500 30 61 124 217 308 657 1,180 1,870 3,880
550 28 58 118 206 292 624 1,120 1,770 3,690
600 27 55 112 196 279 595 1,070 1,690 3,520
650 26 53 108 188 267 570 1,030 1,620 3,370
700 25 51 103 181 256 548 986 1,550 3,240
750 24 49 100 174 247 528 950 1,500 3,120
800 23 47 96 168 239 510 917 1,450 3,010
850 22 46 93 163 231 493 888 1,400 2,920
900 22 44 90 158 224 478 861 1,360 2,830
950 21 43 88 153 217 464 836 1,320 2,740
1,000 20 42 85 149 211 452 813 1,280 2,670
1,100 19 40 81 142 201 429 772 1,220 2,540
1,200 18 38 77 135 192 409 737 1,160 2,420
1,300 18 36 74 129 183 392 705 1,110 2,320
1,400 17 35 71 124 176 376 678 1,070 2,230
1,500 16 34 68 120 170 363 653 1,030 2,140
1,600 16 33 66 116 164 350 630 994 2,070
1,700 15 31 64 112 159 339 610 962 2,000
1,800 15 30 62 108 154 329 592 933 1,940
1,900 14 30 60 105 149 319 575 906 1,890
2,000 14 29 59 102 145 310 559 881 1,830

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.

2 All table entries have been rounded to three significant digits.

TABLE 2413.4(5)

CORRUGATED STAINLESS STEEL TUBING (CSST)

Gas Natural
Inlet Pressure Less than 2 psi
Pressure Drop 0.5 in. w.c.
Specific Gravity 0.60

TUBE SIZE (EHD)
Flow Designation 13 15 18 19 23 25 30 31 37 39 46 48 60 62
Length (ft) Capacity in Cubic Feet of Gas per Hour
5 46 63 115 134 225 270 471 546 895 1,037 1,790 2,070 3,660 4,140
10 32 44 82 95 161 192 330 383 639 746 1,260 1,470 2,600 2,930
15 25 35 66 77 132 157 267 310 524 615 1,030 1,200 2,140 2,400
20 22 31 58 67 116 137 231 269 456 536 888 1,050 1,850 2,080
25 19 27 52 60 104 122 206 240 409 482 793 936 1,660 1,860
30 18 25 47 55 96 112 188 218 374 442 723 856 1,520 1,700
40 15 21 41 47 83 97 162 188 325 386 625 742 1,320 1,470
50 13 19 37 42 75 87 144 168 292 347 559 665 1,180 1,320
60 12 17 34 38 68 80 131 153 267 318 509 608 1,080 1,200
70 11 16 31 36 63 74 121 141 248 295 471 563 1,000 1,110
80 10 15 29 33 60 69 113 132 232 277 440 527 940 1,040
90 10 14 28 32 57 65 107 125 219 262 415 498 887 983
100 9 13 26 30 54 62 101 118 208 249 393 472 843 933
150 7 10 20 23 42 48 78 91 171 205 320 387 691 762
200 6 9 18 21 38 44 71 82 148 179 277 336 600 661
250 5 8 16 19 34 39 63 74 133 161 247 301 538 591
300 5 7 15 17 32 36 57 67 95 148 226 275 492 540

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent length of tubing to the following equation: L = 1.3n, where L is additional length (feet) of tubing and n is the number of additional fittings and/or bends.

2 EHD-Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the greater the gas capacity of the tubing.

3 All table entries have been rounded to three significant digits.

TABLE 2413.4(6)

CORRUGATED STAINLESS STEEL TUBING (CSST)

Gas Natural
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 0.60

TUBE SIZE (EHD)
Flow Designation 13 15 18 19 23 25 30 31 37 39 46 48 60 62
Length (ft) Capacity in Cubic Feet of Gas Per Hour
10 270 353 587 700 1,100 1,370 2,590 2,990 4,510 5,037 9,600 10,700 18,600 21,600
25 166 220 374 444 709 876 1,620 1,870 2,890 3,258 6,040 6,780 11,900 13,700
30 151 200 342 405 650 801 1,480 1,700 2,640 2,987 5,510 6,200 10,900 12,500
40 129 172 297 351 567 696 1,270 1,470 2,300 2,605 4,760 5,380 9,440 10,900
50 115 154 266 314 510 624 1,140 1,310 2,060 2,343 4,260 4,820 8,470 9,720
75 93 124 218 257 420 512 922 1,070 1,690 1,932 3,470 3,950 6,940 7,940
80 89 120 211 249 407 496 892 1,030 1,640 1,874 3,360 3,820 6,730 7,690
100 79 107 189 222 366 445 795 920 1,470 1,685 3,000 3,420 6,030 6,880
150 64 87 155 182 302 364 646 748 1,210 1,389 2,440 2,800 4,940 5,620
200 55 75 135 157 263 317 557 645 1,050 1,212 2,110 2,430 4,290 4,870
250 49 67 121 141 236 284 497 576 941 1,090 1,890 2,180 3,850 4,360
300 44 61 110 129 217 260 453 525 862 999 1,720 1,990 3,520 3,980
400 38 52 96 111 189 225 390 453 749 871 1,490 1,730 3,060 3,450
500 34 46 86 100 170 202 348 404 552 783 1,330 1,550 2,740 3,090

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 Table does not include effect of pressure drop across the line regulator. Where regulator loss exceeds 3/4 psi, DO NOT USE THIS TABLE. Consult with the regulator manufacturer for pressure drops and capacity factors. Pressure drops across a regulator can vary with flow rate.

2 CAUTION: Capacities shown in the table might exceed maximum capacity for a selected regulator. Consult with the regulator or tubing manufacturer for guidance.

3 Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent length of tubing to the following equation: L = 1.3 n where L is additional length (feet) of tubing and n is the number of additional fittings and/or bends.

4 EHD-Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the greater the gas capacity of the tubing.

5 All table entries have been rounded to three significant digits.

TABLE 2413.4(7)

POLYETHYLENE PLASTIC PIPE

Gas Natural
Inlet Pressure Less than 2 psi
Pressure Drop 0.5 in. w.c.
Specific Gravity 0.60

PIPE SIZE (in.)
Nominal OD 1/2 3/4 1 11/4 11/2 2
Designation SDR 9.33 SDR 11.0 SDR 10.00 SDR 11.00 SDR 11.00 SDR 11.00
Actual ID 0.660 0.860 1.077 1.328 1.554 1.943
Length (ft) Capacity in Cubic Feet of Gas per Hour
10 201 403 726 1,260 1,900 3,410
20 138 277 499 865 1,310 2,350
30 111 222 401 695 1,050 1,880
40 95 190 343 594 898 1,610
50 84 169 304 527 796 1,430
60 76 153 276 477 721 1,300
70 70 140 254 439 663 1,190
80 65 131 236 409 617 1,110
90 61 123 221 383 579 1,040
100 58 116 209 362 547 983
125 51 103 185 321 485 871
150 46 93 168 291 439 789
175 43 86 154 268 404 726
200 40 80 144 249 376 675
250 35 71 127 221 333 598
300 32 64 115 200 302 542
350 29 59 106 184 278 499
400 27 55 99 171 258 464
450 26 51 93 160 242 435
500 24 48 88 152 229 411

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Note: All table entries have been rounded to three significant digits.

TABLE 2413.4(8)

POLYETHYLENE PLASTIC PIPE

Gas Natural
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 0.60

PIPE SIZE (in.)
Nominal OD 1/2 3/4 1 11/4 11/2 2
Designation SDR 9.33 SDR 11.0 SDR 11.00 SDR 10.00 SDR 11.00 SDR 11.00
Actual ID 0.660 0.860 1.077 1.328 1.554 1.943
Length (ft) Capacity in Cubic Feet of Gas per Hour
10 1,860 3,720 6,710 11,600 17,600 31,600
20 1,280 2,560 4,610 7,990 12,100 21,700
30 1,030 2,050 3,710 6,420 9,690 17,400
40 878 1,760 3,170 5,490 8,300 14,900
50 778 1,560 2,810 4,870 7,350 13,200
60 705 1,410 2,550 4,410 6,660 12,000
70 649 1,300 2,340 4,060 6,130 11,000
80 603 1,210 2,180 3,780 5,700 10,200
90 566 1,130 2,050 3,540 5,350 9,610
100 535 1,070 1,930 3,350 5,050 9,080
125 474 949 1,710 2,970 4,480 8,050
150 429 860 1,550 2,690 4,060 7,290
175 395 791 1,430 2,470 3,730 6,710
200 368 736 1,330 2,300 3,470 6,240
250 326 652 1,180 2,040 3,080 5,530
300 295 591 1,070 1,850 2,790 5,010
350 272 544 981 1,700 2,570 4,610
400 253 506 913 1,580 2,390 4,290
450 237 475 856 1,480 2,240 4,020
500 224 448 809 1,400 2,120 3,800
550 213 426 768 1,330 2,010 3,610
600 203 406 733 1,270 1,920 3,440
650 194 389 702 1,220 1,840 3,300
700 187 374 674 1,170 1,760 3,170
750 180 360 649 1,130 1,700 3,050
800 174 348 627 1,090 1,640 2,950
850 168 336 607 1,050 1,590 2,850
900 163 326 588 1,020 1,540 2,770
950 158 317 572 990 1,500 2,690
1,000 154 308 556 963 1,450 2,610
1,100 146 293 528 915 1,380 2,480
1,200 139 279 504 873 1,320 2,370
1,300 134 267 482 836 1,260 2,270
1,400 128 257 463 803 1,210 2,180
1,500 124 247 446 773 1,170 2,100
1,600 119 239 431 747 1,130 2,030
1,700 115 231 417 723 1,090 1,960
1,800 112 224 404 701 1,060 1,900
1,900 109 218 393 680 1,030 1,850
2,000 106 212 382 662 1,000 1,800

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

TABLE 2413.4(9)

SCHEDULE 40 METALLIC PIPE

Gas Undiluted Propane
Inlet Pressure 10.0 psi
Pressure Drop 1.0 psi
Specific Gravity 1.50

INTENDED USE Pipe sizing between first stage (high-pressure regulator) and second stage (low-pressure regulator).
PIPE SIZE (in.)
Nominal 1/2 3/4 1 11/4 11/2 2 21/2 3 4
Actual ID 0.622 0.824 1.049 1.380 1.610 2.067 2.469 3.068 4.026
Length (ft) Capacity in Thousands of Btu per Hour
10 3,320 6,950 13,100 26,900 40,300 77,600 124,000 219,000 446,000
20 2,280 4,780 9,000 18,500 27,700 53,300 85,000 150,000 306,000
30 1,830 3,840 7,220 14,800 22,200 42,800 68,200 121,000 246,000
40 1,570 3,280 6,180 12,700 19,000 36,600 58,400 103,000 211,000
50 1,390 2,910 5,480 11,300 16,900 32,500 51,700 91,500 187,000
60 1,260 2,640 4,970 10,200 15,300 29,400 46,900 82,900 169,000
70 1,160 2,430 4,570 9,380 14,100 27,100 43,100 76,300 156,000
80 1,080 2,260 4,250 8,730 13,100 25,200 40,100 70,900 145,000
90 1,010 2,120 3,990 8,190 12,300 23,600 37,700 66,600 136,000
100 956 2,000 3,770 7,730 11,600 22,300 35,600 62,900 128,000
125 848 1,770 3,340 6,850 10,300 19,800 31,500 55,700 114,000
150 768 1,610 3,020 6,210 9,300 17,900 28,600 50,500 103,000
175 706 1,480 2,780 5,710 8,560 16,500 26,300 46,500 94,700
200 657 1,370 2,590 5,320 7,960 15,300 24,400 43,200 88,100
250 582 1,220 2,290 4,710 7,060 13,600 21,700 38,300 78,100
300 528 1,100 2,080 4,270 6,400 12,300 19,600 34,700 70,800
350 486 1,020 1,910 3,930 5,880 11,300 18,100 31,900 65,100
400 452 945 1,780 3,650 5,470 10,500 16,800 29,700 60,600
450 424 886 1,670 3,430 5,140 9,890 15,800 27,900 56,800
500 400 837 1,580 3,240 4,850 9,340 14,900 26,300 53,700
550 380 795 1,500 3,070 4,610 8,870 14,100 25,000 51,000
600 363 759 1,430 2,930 4,400 8,460 13,500 23,900 48,600
650 347 726 1,370 2,810 4,210 8,110 12,900 22,800 46,600
700 334 698 1,310 2,700 4,040 7,790 12,400 21,900 44,800
750 321 672 1,270 2,600 3,900 7,500 12,000 21,100 43,100
800 310 649 1,220 2,510 3,760 7,240 11,500 20,400 41,600
850 300 628 1,180 2,430 3,640 7,010 11,200 19,800 40,300
900 291 609 1,150 2,360 3,530 6,800 10,800 19,200 39,100
950 283 592 1,110 2,290 3,430 6,600 10,500 18,600 37,900
1,000 275 575 1,080 2,230 3,330 6,420 10,200 18,100 36,900
1,100 261 546 1,030 2,110 3,170 6,100 9,720 17,200 35,000
1,200 249 521 982 2,020 3,020 5,820 9,270 16,400 33,400
1,300 239 499 940 1,930 2,890 5,570 8,880 15,700 32,000
1,400 229 480 903 1,850 2,780 5,350 8,530 15,100 30,800
1,500 221 462 870 1,790 2,680 5,160 8,220 14,500 29,600
1,600 213 446 840 1,730 2,590 4,980 7,940 14,000 28,600
1,700 206 432 813 1,670 2,500 4,820 7,680 13,600 27,700
1,800 200 419 789 1,620 2,430 4,670 7,450 13,200 26,900
1,900 194 407 766 1,570 2,360 4,540 7,230 12,800 26,100
2,000 189 395 745 1,530 2,290 4,410 7,030 12,400 25,400

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Note: All table entries have been rounded to three significant digits.

TABLE 2413.4(10)

SCHEDULE 40 METALLIC PIPE

Gas Undiluted Propane
Inlet Pressure 10.0 psi
Pressure Drop 3.0 psi
Specific Gravity 1.50

INTENDED USE Pipe sizing between first stage (high-pressure regulator) and second stage (low-pressure regulator).
PIPE SIZE (in)
Nominal 1/2 3/4 1 11/4 11/2 2 21/2 3 4
Actual ID 0.622 0.824 1.049 1.380 1.610 2.067 2.469 3.068 4.026
Length (ft) Capacity in Thousands of Btu per Hour
10 5,890 12,300 23,200 47,600 71,300 137,000 219,000 387,000 789,000
20 4,050 8,460 15,900 32,700 49,000 94,400 150,000 266,000 543,000
30 3,250 6,790 12,800 26,300 39,400 75,800 121,000 214,000 436,000
40 2,780 5,810 11,000 22,500 33,700 64,900 103,000 183,000 373,000
50 2,460 5,150 9,710 19,900 29,900 57,500 91,600 162,000 330,000
60 2,230 4,670 8,790 18,100 27,100 52,100 83,000 147,000 299,000
70 2,050 4,300 8,090 16,600 24,900 47,900 76,400 135,000 275,000
80 1,910 4,000 7,530 15,500 23,200 44,600 71,100 126,000 256,000
90 1,790 3,750 7,060 14,500 21,700 41,800 66,700 118,000 240,000
100 1,690 3,540 6,670 13,700 20,500 39,500 63,000 111,000 227,000
125 1,500 3,140 5,910 12,100 18,200 35,000 55,800 98,700 201,000
150 1,360 2,840 5,360 11,000 16,500 31,700 50,600 89,400 182,000
175 1,250 2,620 4,930 10,100 15,200 29,200 46,500 82,300 167,800
200 1,160 2,430 4,580 9,410 14,100 27,200 43,300 76,500 156,100
250 1,030 2,160 4,060 8,340 12,500 24,100 38,400 67,800 138,400
300 935 1,950 3,680 7,560 11,300 21,800 34,800 61,500 125,400
350 860 1,800 3,390 6,950 10,400 20,100 32,000 56,500 115,300
400 800 1,670 3,150 6,470 9,690 18,700 29,800 52,600 107,300
450 751 1,570 2,960 6,070 9,090 17,500 27,900 49,400 100,700
500 709 1,480 2,790 5,730 8,590 16,500 26,400 46,600 95,100
550 673 1,410 2,650 5,450 8,160 15,700 25,000 44,300 90,300
600 642 1,340 2,530 5,200 7,780 15,000 23,900 42,200 86,200
650 615 1,290 2,420 4,980 7,450 14,400 22,900 40,500 82,500
700 591 1,240 2,330 4,780 7,160 13,800 22,000 38,900 79,300
750 569 1,190 2,240 4,600 6,900 13,300 21,200 37,400 76,400
800 550 1,150 2,170 4,450 6,660 12,800 20,500 36,200 73,700
850 532 1,110 2,100 4,300 6,450 12,400 19,800 35,000 71,400
900 516 1,080 2,030 4,170 6,250 12,000 19,200 33,900 69,200
950 501 1,050 1,970 4,050 6,070 11,700 18,600 32,900 67,200
1,000 487 1,020 1,920 3,940 5,900 11,400 18,100 32,000 65,400
1,100 463 968 1,820 3,740 5,610 10,800 17,200 30,400 62,100
1,200 442 923 1,740 3,570 5,350 10,300 16,400 29,000 59,200
1,300 423 884 1,670 3,420 5,120 9,870 15,700 27,800 56,700
1,400 406 849 1,600 3,280 4,920 9,480 15,100 26,700 54,500
1,500 391 818 1,540 3,160 4,740 9,130 14,600 25,700 52,500
1,600 378 790 1,490 3,060 4,580 8,820 14,100 24,800 50,700
1,700 366 765 1,440 2,960 4,430 8,530 13,600 24,000 49,000
1,800 355 741 1,400 2,870 4,300 8,270 13,200 23,300 47,600
1,900 344 720 1,360 2,780 4,170 8,040 12,800 22,600 46,200
2,000 335 700 1,320 2,710 4,060 7,820 12,500 22,000 44,900

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Note: All table entries have been rounded to three significant digits.

TABLE 2413.4(11)

SCHEDULE 40 METALLIC PIPE

Gas Undiluted Propane
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 1.50

INTENDED USE Pipe sizing between 2 psig service and line pressure regulator.
PIPE SIZE (in.)
Nominal 1/2 3/4 1 11/4 11/2 2 21/2 3 4
Actual ID 0.622 0.824 1.049 1.380 1.610 2.067 2.469 3.068 4.026
Length (ft) Capacity in Thousands of Btu per Hour
10 2,680 5,590 10,500 21,600 32,400 62,400 99,500 176,000 359,000
20 1,840 3,850 7,240 14,900 22,300 42,900 68,400 121,000 247,000
30 1,480 3,090 5,820 11,900 17,900 34,500 54,900 97,100 198,000
40 1,260 2,640 4,980 10,200 15,300 29,500 47,000 83,100 170,000
50 1,120 2,340 4,410 9,060 13,600 26,100 41,700 73,700 150,000
60 1,010 2,120 4,000 8,210 12,300 23,700 37,700 66,700 136,000
70 934 1,950 3,680 7,550 11,300 21,800 34,700 61,400 125,000
80 869 1,820 3,420 7,020 10,500 20,300 32,300 57,100 116,000
90 815 1,700 3,210 6,590 9,880 19,000 30,300 53,600 109,000
100 770 1,610 3,030 6,230 9,330 18,000 28,600 50,600 103,000
125 682 1,430 2,690 5,520 8,270 15,900 25,400 44,900 91,500
150 618 1,290 2,440 5,000 7,490 14,400 23,000 40,700 82,900
175 569 1,190 2,240 4,600 6,890 13,300 21,200 37,400 76,300
200 529 1,110 2,080 4,280 6,410 12,300 19,700 34,800 71,000
250 469 981 1,850 3,790 5,680 10,900 17,400 30,800 62,900
300 425 889 1,670 3,440 5,150 9,920 15,800 27,900 57,000
350 391 817 1,540 3,160 4,740 9,120 14,500 25,700 52,400
400 364 760 1,430 2,940 4,410 8,490 13,500 23,900 48,800
450 341 714 1,340 2,760 4,130 7,960 12,700 22,400 45,800
500 322 674 1,270 2,610 3,910 7,520 12,000 21,200 43,200
550 306 640 1,210 2,480 3,710 7,140 11,400 20,100 41,100
600 292 611 1,150 2,360 3,540 6,820 10,900 19,200 39,200
650 280 585 1,100 2,260 3,390 6,530 10,400 18,400 37,500
700 269 562 1,060 2,170 3,260 6,270 9,990 17,700 36,000
750 259 541 1,020 2,090 3,140 6,040 9,630 17,000 34,700
800 250 523 985 2,020 3,030 5,830 9,300 16,400 33,500
850 242 506 953 1,960 2,930 5,640 9,000 15,900 32,400
900 235 490 924 1,900 2,840 5,470 8,720 15,400 31,500
950 228 476 897 1,840 2,760 5,310 8,470 15,000 30,500
1,000 222 463 873 1,790 2,680 5,170 8,240 14,600 29,700
1,100 210 440 829 1,700 2,550 4,910 7,830 13,800 28,200
1,200 201 420 791 1,620 2,430 4,680 7,470 13,200 26,900
1,300 192 402 757 1,550 2,330 4,490 7,150 12,600 25,800
1,400 185 386 727 1,490 2,240 4,310 6,870 12,100 24,800
1,500 178 372 701 1,440 2,160 4,150 6,620 11,700 23,900
1,600 172 359 677 1,390 2,080 4,010 6,390 11,300 23,000
1,700 166 348 655 1,340 2,010 3,880 6,180 10,900 22,300
1,800 161 337 635 1,300 1,950 3,760 6,000 10,600 21,600
1,900 157 327 617 1,270 1,900 3,650 5,820 10,300 21,000
2,000 152 318 600 1,230 1,840 3,550 5,660 10,000 20,400

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Note: All table entries have been rounded to three significant digits.

TABLE 2413.4(12)

SCHEDULE 40 METALLIC PIPE

Gas Undiluted Propane
Inlet Pressure 11.0 in. w.c.
Pressure Drop 0.5 in. w.c.
Specific Gravity 1.50

INTENDED USE Pipe sizing between single- or second-stage (low pressure) regulator and appliance.
PIPE SIZE (in.)
Nominal 1/2 3/4 1 11/4 11/2 2 21/2 3 4
Actual ID 0.622 0.824 1.049 1.380 1.610 2.067 2.469 3.068 4.026
Length (ft) Capacity in Thousands of Btu per Hour
10 291 608 1,150 2,350 3,520 6,790 10,800 19,100 39,000
20 200 418 787 1,620 2,420 4,660 7,430 13,100 26,800
30 160 336 632 1,300 1,940 3,750 5,970 10,600 21,500
40 137 287 541 1,110 1,660 3,210 5,110 9,030 18,400
50 122 255 480 985 1,480 2,840 4,530 8,000 16,300
60 110 231 434 892 1,340 2,570 4,100 7,250 14,800
80 101 212 400 821 1,230 2,370 3,770 6,670 13,600
100 94 197 372 763 1,140 2,200 3,510 6,210 12,700
125 89 185 349 716 1,070 2,070 3,290 5,820 11,900
150 84 175 330 677 1,010 1,950 3,110 5,500 11,200
175 74 155 292 600 899 1,730 2,760 4,880 9,950
200 67 140 265 543 814 1,570 2,500 4,420 9,010
250 62 129 243 500 749 1,440 2,300 4,060 8,290
300 58 120 227 465 697 1,340 2,140 3,780 7,710
350 51 107 201 412 618 1,190 1,900 3,350 6,840
400 46 97 182 373 560 1,080 1,720 3,040 6,190
450 42 89 167 344 515 991 1,580 2,790 5,700
500 40 83 156 320 479 922 1,470 2,600 5,300
550 37 78 146 300 449 865 1,380 2,440 4,970
600 35 73 138 283 424 817 1,300 2,300 4,700
650 33 70 131 269 403 776 1,240 2,190 4,460
700 32 66 125 257 385 741 1,180 2,090 4,260
750 30 64 120 246 368 709 1,130 2,000 4,080
800 29 61 115 236 354 681 1,090 1,920 3,920
850 28 59 111 227 341 656 1,050 1,850 3,770
900 27 57 107 220 329 634 1,010 1,790 3,640
950 26 55 104 213 319 613 978 1,730 3,530
1,000 25 53 100 206 309 595 948 1,680 3,420
1,100 25 52 97 200 300 578 921 1,630 3,320
1,200 24 50 95 195 292 562 895 1,580 3,230
1,300 23 48 90 185 277 534 850 1,500 3,070
1,400 22 46 86 176 264 509 811 1,430 2,930
1,500 21 44 82 169 253 487 777 1,370 2,800
1,600 20 42 79 162 243 468 746 1,320 2,690
1,700 19 40 76 156 234 451 719 1,270 2,590
1,800 19 39 74 151 226 436 694 1,230 2,500
1,900 18 38 71 146 219 422 672 1,190 2,420
2,000 18 37 69 142 212 409 652 1,150 2,350

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

TABLE 2413.4(13)

SEMIRIGID COPPER TUBING

Gas Undiluted Propane
Inlet Pressure 10.0 psi
Pressure Drop 1.0 psi
Specific Gravity 1.50

INTENDED USE Sizing between first stage (high-pressure regulator) and second stage (low-pressure regulator).
TUBE SIZE (in.)
Nominal K & L 1/4 3/8 1/2 5/8 3/4 1 11/4 11/2 2
ACR 3/8 1/2 5/8 3/4 7/8 11/8 13/8 - -
Outside 0.375 0.500 0.625 0.750 0.875 1.125 1.375 1.625 2.125
Inside 0.305 0.402 0.527 0.652 0.745 0.995 1.245 1.959 1.959
Length (ft) Capacity in Thousands of Btu per Hour
10 513 1,060 2,150 3,760 5,330 11,400 20,500 32,300 67,400
20 352 727 1,480 2,580 3,670 7,830 14,100 22,200 46,300
30 283 584 1,190 2,080 2,940 6,290 11,300 17,900 37,200
40 242 500 1,020 1,780 2,520 5,380 9,690 15,300 31,800
50 215 443 901 1,570 2,230 4,770 8,590 13,500 28,200
60 194 401 816 1,430 2,020 4,320 7,780 12,300 25,600
70 179 369 751 1,310 1,860 3,980 7,160 11,300 23,500
80 166 343 699 1,220 1,730 3,700 6,660 10,500 21,900
90 156 322 655 1,150 1,630 3,470 6,250 9,850 20,500
100 147 304 619 1,080 1,540 3,280 5,900 9,310 19,400
125 131 270 549 959 1,360 2,910 5,230 8,250 17,200
150 118 244 497 869 1,230 2,630 4,740 7,470 15,600
175 109 225 457 799 1,130 2,420 4,360 6,880 14,300
200 101 209 426 744 1,060 2,250 4,060 6,400 13,300
250 90 185 377 659 935 2,000 3,600 5,670 11,800
300 81 168 342 597 847 1,810 3,260 5,140 10,700
350 75 155 314 549 779 1,660 3,000 4,730 9,840
400 70 144 292 511 725 1,550 2,790 4,400 9,160
450 65 135 274 480 680 1,450 2,620 4,130 8,590
500 62 127 259 453 643 1,370 2,470 3,900 8,120
550 59 121 246 430 610 1,300 2,350 3,700 7,710
600 56 115 235 410 582 1,240 2,240 3,530 7,350
650 54 111 225 393 558 1,190 2,140 3,380 7,040
700 51 106 216 378 536 1,140 2,060 3,250 6,770
750 50 102 208 364 516 1,100 1,980 3,130 6,520
800 48 99 201 351 498 1,060 1,920 3,020 6,290
850 46 96 195 340 482 1,030 1,850 2,920 6,090
900 45 93 189 330 468 1,000 1,800 2,840 5,910
950 44 90 183 320 454 970 1,750 2,750 5,730
1,000 42 88 178 311 442 944 1,700 2,680 5,580
1,100 40 83 169 296 420 896 1,610 2,540 5,300
1,200 38 79 161 282 400 855 1,540 2,430 5,050
1,300 37 76 155 270 383 819 1,470 2,320 4,840
1,400 35 73 148 260 368 787 1,420 2,230 4,650
1,500 34 70 143 250 355 758 1,360 2,150 4,480
1,600 33 68 138 241 343 732 1,320 2,080 4,330
1,700 32 66 134 234 331 708 1,270 2,010 4,190
1,800 31 64 130 227 321 687 1,240 1,950 4,060
1,900 30 62 126 220 312 667 1,200 1,890 3,940
2,000 29 60 122 214 304 648 1,170 1,840 3,830

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.

2 All table entries have been rounded to three significant digits.

TABLE 2413.4(14)

SEMIRIGID COPPER TUBING

Gas Undiluted Propane
Inlet Pressure 11.0 in. w.c.
Pressure Drop 0.5 in. w.c.
Specific Gravity 1.50

INTENDED USE Sizing between single- or second-stage (low-pressure regulator) and appliance.
TUBE SIZE (in.)
Nominal K & L 1/4 3/8 1/2 5/8 3/4 1 11/4 11/2 2
ACR 3/8 1/2 5/8 3/4 7/8 11/8 13/8 - -
Outside 0.375 0.500 0.625 0.750 0.875 1.125 1.375 1.625 2.125
Inside 0.305 0.402 0.527 0.652 0.745 0.995 1.245 1.481 1.959
Length (ft) Capacity in Thousands of Btu per Hour
10 45 93 188 329 467 997 1,800 2,830 5,890
20 31 64 129 226 321 685 1,230 1,950 4,050
30 25 51 104 182 258 550 991 1,560 3,250
40 21 44 89 155 220 471 848 1,340 2,780
50 19 39 79 138 195 417 752 1,180 2,470
60 17 35 71 125 177 378 681 1,070 2,240
70 16 32 66 115 163 348 626 988 2,060
80 15 30 61 107 152 324 583 919 1,910
90 14 28 57 100 142 304 547 862 1,800
100 13 27 54 95 134 287 517 814 1,700
125 11 24 48 84 119 254 458 722 1,500
150 10 21 44 76 108 230 415 654 1,360
175 NA 20 40 70 99 212 382 602 1,250
200 NA 18 37 65 92 197 355 560 1,170
250 NA 16 33 58 82 175 315 496 1,030
300 NA 15 30 52 74 158 285 449 936
350 NA 14 28 48 68 146 262 414 861
400 NA 13 26 45 63 136 244 385 801
450 NA 12 24 42 60 127 229 361 752
500 NA 11 23 40 56 120 216 341 710
550 NA 11 22 38 53 114 205 324 674
600 NA 10 21 36 51 109 196 309 643
650 NA NA 20 34 49 104 188 296 616
700 NA NA 19 33 47 100 180 284 592
750 NA NA 18 32 45 96 174 274 570
800 NA NA 18 31 44 93 168 264 551
850 NA NA 17 30 42 90 162 256 533
900 NA NA 17 29 41 87 157 248 517
950 NA NA 16 28 40 85 153 241 502
1,000 NA NA 16 27 39 83 149 234 488
1,100 NA NA 15 26 37 78 141 223 464
1,200 NA NA 14 25 35 75 135 212 442
1,300 NA NA 14 24 34 72 129 203 423
1,400 NA NA 13 23 32 69 124 195 407
1,500 NA NA 13 22 31 66 119 188 392
1,600 NA NA 12 21 30 64 115 182 378
1,700 NA NA 12 20 29 62 112 176 366
1,800 NA NA 11 20 28 60 108 170 355
1,900 NA NA 11 19 27 58 105 166 345
2,000 NA NA 11 19 27 57 102 161 335

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.

2 NA means a flow of less than 10,000 Btu/hr.

3 All table entries have been rounded to three significant digits.

TABLE 2413.4(15)

SEMIRIGID COPPER TUBING

Gas Undiluted Propane
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 1.50

INTENDED USE Tube sizing between 2 psig service and line pressure regulator. TUBE SIZE (in.)
TUBE SIZE (in.)
Nominal K & L 1/4 3/8 1/2 5/8 3/4 1 11/4 11/2 2
ACR 3/8 1/2 5/8 3/4 7/8 11/8 13/8 - -
Outside 0.375 0.500 0.625 0.750 0.875 1.125 1.375 1.625 2.125
Inside 0.305 0.402 0.527 0.652 0.745 0.995 1.245 1.481 1.959
Length (ft) Capacity in Thousands of Btu per Hour
10 413 852 1,730 3,030 4,300 9,170 16,500 26,000 54,200
20 284 585 1,190 2,080 2,950 6,310 11,400 17,900 37,300
30 228 470 956 1,670 2,370 5,060 9,120 14,400 29,900
40 195 402 818 1,430 2,030 4,330 7,800 12,300 25,600
50 173 356 725 1,270 1,800 3,840 6,920 10,900 22,700
60 157 323 657 1,150 1,630 3,480 6,270 9,880 20,600
70 144 297 605 1,060 1,500 3,200 5,760 9,090 18,900
80 134 276 562 983 1,390 2,980 5,360 8,450 17,600
90 126 259 528 922 1,310 2,790 5,030 7,930 16,500
100 119 245 498 871 1,240 2,640 4,750 7,490 15,600
125 105 217 442 772 1,100 2,340 4,210 6,640 13,800
150 95 197 400 700 992 2,120 3,820 6,020 12,500
175 88 181 368 644 913 1,950 3,510 5,540 11,500
200 82 168 343 599 849 1,810 3,270 5,150 10,700
250 72 149 304 531 753 1,610 2,900 4,560 9,510
300 66 135 275 481 682 1,460 2,620 4,140 8,610
350 60 124 253 442 628 1,340 2,410 3,800 7,920
400 56 116 235 411 584 1,250 2,250 3,540 7,370
450 53 109 221 386 548 1,170 2,110 3,320 6,920
500 50 103 209 365 517 1,110 1,990 3,140 6,530
550 47 97 198 346 491 1,050 1,890 2,980 6,210
600 45 93 189 330 469 1,000 1,800 2,840 5,920
650 43 89 181 316 449 959 1,730 2,720 5,670
700 41 86 174 304 431 921 1,660 2,620 5,450
750 40 82 168 293 415 888 1,600 2,520 5,250
800 39 80 162 283 401 857 1,540 2,430 5,070
850 37 77 157 274 388 829 1,490 2,350 4,900
900 36 75 152 265 376 804 1,450 2,280 4,750
950 35 72 147 258 366 781 1,410 2,220 4,620
1,000 34 71 143 251 356 760 1,370 2,160 4,490
1,100 32 67 136 238 338 721 1,300 2,050 4,270
1,200 31 64 130 227 322 688 1,240 1,950 4,070
1,300 30 61 124 217 309 659 1,190 1,870 3,900
1,400 28 59 120 209 296 633 1,140 1,800 3,740
1,500 27 57 115 201 286 610 1,100 1,730 3,610
1,600 26 55 111 194 276 589 1,060 1,670 3,480
1,700 26 53 108 188 267 570 1,030 1,620 3,370
1,800 25 51 104 182 259 553 1,000 1,570 3,270
1,900 24 50 101 177 251 537 966 1,520 3,170
2,000 23 48 99 172 244 522 940 1,480 3,090

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.

2 All table entries have been rounded to three significant digits.

TABLE 2413.4(16)

CORRUGATED STAINLESS STEEL TUBING (CSST)

Gas Undiluted Propane
Inlet Pressure 11.0 in. w.c.
Pressure Drop 0.5 in. w.c.
Specific Gravity 1.50

INTENDED USE Sizing between single or second stage (low pressure) regulator and the appliance shutoff valve.
TUBE SIZE (EHD)
Flow Designation 13 15 18 19 23 25 30 31 37 39 46 48 60 62
Length (ft) Capacity in Thousands of Btu per Hour
5 72 99 181 211 355 426 744 863 1,420 1,638 2,830 3,270 5,780 6,550
10 50 69 129 150 254 303 521 605 971 1,179 1,990 2,320 4,110 4,640
15 39 55 104 121 208 248 422 490 775 972 1,620 1,900 3,370 3,790
20 34 49 91 106 183 216 365 425 661 847 1,400 1,650 2,930 3,290
25 30 42 82 94 164 192 325 379 583 762 1,250 1,480 2,630 2,940
30 28 39 74 87 151 177 297 344 528 698 1,140 1,350 2,400 2,680
40 23 33 64 74 131 153 256 297 449 610 988 1,170 2,090 2,330
50 20 30 58 66 118 137 227 265 397 548 884 1,050 1,870 2,080
60 19 26 53 60 107 126 207 241 359 502 805 961 1,710 1,900
70 17 25 49 57 99 117 191 222 330 466 745 890 1,590 1,760
80 15 23 45 52 94 109 178 208 307 438 696 833 1,490 1,650
90 15 22 44 50 90 102 169 197 286 414 656 787 1,400 1,550
100 14 20 41 47 85 98 159 186 270 393 621 746 1,330 1,480
150 11 15 31 36 66 75 123 143 217 324 506 611 1,090 1,210
200 9 14 28 33 60 69 112 129 183 283 438 531 948 1,050
250 8 12 25 30 53 61 99 117 163 254 390 476 850 934
300 8 11 23 26 50 57 90 107 147 234 357 434 777 854

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent length of tubing to the following equation: L = 1.3n where L is additional length (feet) of tubing and n is the number of additional fittings and/or bends.

2 EHD-Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the greater the gas capacity of the tubing.

3 All table entries have been rounded to three significant digits.

TABLE 2413.4(17)

CORRUGATED STAINLESS STEEL TUBING (CSST)

Gas Undiluted Propane
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 1.50

INTENDED USE Sizing between 2 psi service and the line pressure regulator.
TUBE SIZE (EHD)
Flow Designation 13 15 18 19 23 25 30 31 37 39 46 48 60 62
Length (ft) Capacity in Thousands of Btu per Hour
10 426 558 927 1,110 1,740 2,170 4,100 4,720 7,130 7,958 15,200 16,800 29,400 34,200
25 262 347 591 701 1,120 1,380 2,560 2,950 4,560 5,147 9,550 10,700 18,800 21,700
30 238 316 540 640 1,030 1,270 2,330 2,690 4,180 4,719 8,710 9,790 17,200 19,800
40 203 271 469 554 896 1,100 2,010 2,320 3,630 4,116 7,530 8,500 14,900 17,200
50 181 243 420 496 806 986 1,790 2,070 3,260 3,702 6,730 7,610 13,400 15,400
75 147 196 344 406 663 809 1,460 1,690 2,680 3,053 5,480 6,230 11,000 12,600
80 140 189 333 393 643 768 1,410 1,630 2,590 2,961 5,300 6,040 10,600 12,200
100 124 169 298 350 578 703 1,260 1,450 2,330 2,662 4,740 5,410 9,530 10,900
150 101 137 245 287 477 575 1,020 1,180 1,910 2,195 3,860 4,430 7,810 8,890
200 86 118 213 248 415 501 880 1,020 1,660 1,915 3,340 3,840 6,780 7,710
250 77 105 191 222 373 448 785 910 1,490 1,722 2,980 3,440 6,080 6,900
300 69 96 173 203 343 411 716 829 1,360 1,578 2,720 3,150 5,560 6,300
400 60 82 151 175 298 355 616 716 1,160 1,376 2,350 2,730 4,830 5,460
500 53 72 135 158 268 319 550 638 1,030 1,237 2,100 2,450 4,330 4,880

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 Table does not include effect of pressure drop across the line regulator. Where regulator loss exceeds 1/2 psi (based on 13 in. w.c. outlet pressure), DO NOT USE THIS TABLE. Consult with the regulator manufacturer for pressure drops and capacity factors. Pressure drops across a regulator can vary with flow rate.

2 CAUTION: Capacities shown in the table might exceed maximum capacity for a selected regulator. Consult with the regulator or tubing manufacturer for guidance.

3 Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent length of tubing to the following equation: L = 1.3n where L is additional length (feet) of tubing and n is the number of additional fittings and/or bends.

4 EHD-Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the greater the gas capacity of the tubing.

5 All table entries have been rounded to three significant digits.

TABLE 2413.4(18)

CORRUGATED STAINLESS STEEL TUBING (CSST)

Gas Undiluted Propane
Inlet Pressure 5.0 psi
Pressure Drop 3.5 psi
Specific Gravity 1.50

TUBE SIZE (EHD)
Flow Designation 13 15 18 19 23 25 30 31 37 39 46 48 60 62
Length (ft) Capacity in Thousands of Btu per Hour
10 826 1,070 1,710 2,060 3,150 4,000 7,830 8,950 13,100 14,441 28,600 31,200 54,400 63,800
25 509 664 1,090 1,310 2,040 2,550 4,860 5,600 8,400 9,339 18,000 19,900 34,700 40,400
30 461 603 999 1,190 1,870 2,340 4,430 5,100 7,680 8,564 16,400 18,200 31,700 36,900
40 396 520 867 1,030 1,630 2,030 3,820 4,400 6,680 7,469 14,200 15,800 27,600 32,000
50 352 463 777 926 1,460 1,820 3,410 3,930 5,990 6,717 12,700 14,100 24,700 28,600
75 284 376 637 757 1,210 1,490 2,770 3,190 4,920 5,539 10,300 11,600 20,300 23,400
80 275 363 618 731 1,170 1,450 2,680 3,090 4,770 5,372 9,990 11,200 19,600 22,700
100 243 324 553 656 1,050 1,300 2,390 2,760 4,280 4,830 8,930 10,000 17,600 20,300
150 196 262 453 535 866 1,060 1,940 2,240 3,510 3,983 7,270 8,210 14,400 16,600
200 169 226 393 464 755 923 1,680 1,930 3,050 3,474 6,290 7,130 12,500 14,400
250 150 202 352 415 679 828 1,490 1,730 2,740 3,124 5,620 6,390 11,200 12,900
300 136 183 322 379 622 757 1,360 1,570 2,510 2,865 5,120 5,840 10,300 11,700
400 117 158 279 328 542 657 1,170 1,360 2,180 2,498 4,430 5,070 8,920 10,200
500 104 140 251 294 488 589 1,050 1,210 1,950 2,247 3,960 4,540 8,000 9,110

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Notes:

1 Table does not include effect of pressure drop across line regulator. Where regulator loss exceeds1 psi, DO NOT USE THIS TABLE. Consult with the regulator manufacturer for pressure drops and capacity factors. Pressure drop across regulator can vary with the flow rate.

2 CAUTION: Capacities shown in the table might exceed maximum capacity of selected regulator. Consult with the tubing manufacturer for guidance.

3 Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends and/or fittings shall be increased by an equivalent length of tubing to the following equation: L = 1.3n where L is additional length (feet) of tubing and n is the number of additional fittings and/or bends.

4 EHD- Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between different tubing sizes. The greater the value of EHD, the greater the gas capacity of the tubing.

5 All table entries have been rounded to three significant digits.

TABLE 2413.4(19)

POLYETHYLENE PLASTIC PIPE

Gas Undiluted Propane
Inlet Pressure 11.0 in. w.c.
Pressure Drop 0.5 in. w.c.
Specific Gravity 1.50

INTENDED USE PE pipe sizing between integral 2-stage regulator at tank or second stage (low pressure regulator) and building.
PIPE SIZE (in.)
Nominal OD 1/2 3/4 1 11/4 11/2 2
Designation SDR 9.33 SDR 11.0 SDR 11.00 SDR 10.00 SDR 11.00 SDR 11.00
Actual ID 0.660 0.860 1.077 1.328 1.554 1.943
Length (ft) Capacity in Thousands of Btu per Hour
10 340 680 1,230 2,130 3,210 5,770
20 233 468 844 1,460 2,210 3,970
30 187 375 677 1,170 1,770 3,180
40 160 321 580 1,000 1,520 2,730
50 142 285 514 890 1,340 2,420
60 129 258 466 807 1,220 2,190
70 119 237 428 742 1,120 2,010
80 110 221 398 690 1,040 1,870
90 103 207 374 648 978 1,760
100 98 196 353 612 924 1,660
125 87 173 313 542 819 1,470
150 78 157 284 491 742 1,330
175 72 145 261 452 683 1,230
200 67 135 243 420 635 1,140
250 60 119 215 373 563 1,010
300 54 108 195 338 510 916
350 50 99 179 311 469 843
400 46 92 167 289 436 784
450 43 87 157 271 409 736
500 41 82 148 256 387 695

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad. Note: All table entries have been rounded to three significant digits.

TABLE 2413.4(20)

POLYETHYLENE PLASTIC PIPE

Gas Undiluted Propane
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 1.50

INTENDED USE PE pipe sizing between 2 psig service regulator and line pressure regulator.
PIPE SIZE (in.)
Nominal OD 1/2 3/4 1 11/4 11/2 2
Designation SDR 9.33 SDR 11.0 SDR 11.00 SDR 10.00 SDR 11.00 SDR 11.00
Actual ID 0.660 0.860 1.077 1.328 1.554 1.943
Length (ft) Capacity in Thousands of Btu per Hou
10 3,130 6,260 11,300 19,600 29,500 53,100
20 2,150 4,300 7,760 13,400 20,300 36,500
30 1,730 3,450 6,230 10,800 16,300 29,300
40 1,480 2,960 5,330 9,240 14,000 25,100
50 1,310 2,620 4,730 8,190 12,400 22,200
60 1,190 2,370 4,280 7,420 11,200 20,100
70 1,090 2,180 3,940 6,830 10,300 18,500
80 1,010 2,030 3,670 6,350 9,590 17,200
90 952 1,910 3,440 5,960 9,000 16,200
100 899 1,800 3,250 5,630 8,500 15,300
125 797 1,600 2,880 4,990 7,530 13,500
150 722 1,450 2,610 4,520 6,830 12,300
175 664 1,330 2,400 4,160 6,280 11,300
200 618 1,240 2,230 3,870 5,840 10,500
250 548 1,100 1,980 3,430 5,180 9,300
300 496 994 1,790 3,110 4,690 8,430
350 457 914 1,650 2,860 4,320 7,760
400 425 851 1,530 2,660 4,020 7,220
450 399 798 1,440 2,500 3,770 6,770
500 377 754 1,360 2,360 3,560 6,390
550 358 716 1,290 2,240 3,380 6,070
600 341 683 1,230 2,140 3,220 5,790
650 327 654 1,180 2,040 3,090 5,550
700 314 628 1,130 1,960 2,970 5,330
750 302 605 1,090 1,890 2,860 5,140
800 292 585 1,050 1,830 2,760 4,960
850 283 566 1,020 1,770 2,670 4,800
900 274 549 990 1,710 2,590 4,650
950 266 533 961 1,670 2,520 4,520
1,000 259 518 935 1,620 2,450 4,400
1,100 246 492 888 1,540 2,320 4,170
1,200 234 470 847 1,470 2,220 3,980
1,300 225 450 811 1,410 2,120 3,810
1,400 216 432 779 1,350 2,040 3,660
1,500 208 416 751 1,300 1,960 3,530
1,600 201 402 725 1,260 1,900 3,410
1,700 194 389 702 1,220 1,840 3,300
1,800 188 377 680 1,180 1,780 3,200
1,900 183 366 661 1,140 1,730 3,110
2,000 178 356 643 1,110 1,680 3,020

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Note: All table entries have been rounded to three significant digits.

TABLE 2413.4(21)

POLYETHYLENE PLASTIC TUBING

Gas Undiluted Propane
Inlet Pressure 11.0 in. w.c.
Pressure Drop 0.5 in. w.c.
Specific Gravity 1.50
INTENDED USE PE pipe sizing between integral 2-stage regulator at tank or second stage (low pressure regulator) and building.
  Plastic Tubing Size (CTS) (in.)
Nominal OD 1/2 1
Designation SDR 7.00 SDR 11.00
Actual ID 0.445 0.927
Length (ft) Capacity in Cubic Feet of Gas per Hour
10 121 828
20 83 569
30 67 457
40 57 391
50 51 347
60 46 314
70 42 289
80 39 269
90 37 252
100 35 238
125 31 211
150 28 191
175 26 176
200 24 164
225 22 154
250 21 145
275 20 138
300 19 132
350 18 121
400 16 113
450 15 106
500 15 100

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Note: All table entries have been rounded to three significant digits.

SECTION 2414

PIPING MATERIALS

2414.1 General. Materials used for piping systems shall comply with the requirements of this chapter or shall be approved.

2414.2 Used materials. Pipe, fittings, valves or other materials shall not be used again unless they are free of foreign materials and have been ascertained to be adequate for the service intended.

2414.3 Other materials. Material not covered by the standards specifications listed herein shall be investigated and tested to determine that it is safe and suitable for the proposed service, and, in addition, shall be recommended for that service by the manufacturer and shall be approved by the building official.

2414.4 Metallic pipe. Metallic pipe shall comply with Sections 2414.4.1 and 2414.4.2.

2414.4.1 Cast iron. Cast-iron pipe shall not be used.

2414.4.2 Steel. Steel and wrought-iron pipe shall be at least of standard weight (Schedule 40) and shall comply with one of the following:

1. ASME B 36.10, 10M;

2. ASTM A 53/A 53M; or

3. ASTM A 106.

2414.5 Metallic tubing. Seamless copper, aluminum alloy or steel tubing shall be permitted to be used with gases not corrosive to such material.

2414.5.1 Steel tubing. Steel tubing shall comply with ASTM A 254.

2414.5.2 Copper tubing. Copper tubing shall comply with standard Type K or L of ASTM B 88 or ASTM B 280.

Copper and brass tubing shall not be used if the gas contains more than an average of 0.3 grains of hydrogen sulfide per 100 standard cubic feet of gas ( 0.7 milligrams per 100 liters).

2414.5.3 Corrugated stainless steel tubing. Corrugated stainless steel tubing shall be listed in accordance with ANSI LC 1/CSA 6.26.

2414.6 Plastic pipe, tubing and fittings. Plastic pipe, tubing and fittings used to supply fuel gas shall conform to ASTM D 2513. Pipe shall be marked "Gas" and "ASTM D 2513."

2414.6.1 Anodeless risers. Anodeless risers shall comply with the following:

1. Factory-assembled anodeless risers shall be recommended by the manufacturer for the gas used and shall be leak-tested by the manufacturer in accordance with written procedures.

2. Service head adapters and field-assembled anodeless risers incorporating service head adapters shall be recommended by the manufacturer for the gas used by the manufacturer and shall be designed certified to meet the requirements of Category I of ASTM D 2513, and U.S. Department of Transportation, Code of Federal Regulations, Title 49, Part 192.281(e). The manufacturer shall provide the user qualified installation instructions as prescribed by the U.S. Department of Transportation, Code of Federal Regulations, Title 49, Part 192.283(b).

2414.6.2 LP-gas systems. The use of plastic pipe, tubing and fittings in undiluted liquefied petroleum gas piping systems shall be in accordance with NFPA 58.

2414.6.3 Regulator vent piping. Plastic pipe, tubing and fittings used to connect regulator vents to remote vent terminations shall be of PVC conforming to ANSI/UL 651. PVC vent piping shall not be installed indoors.

2414.7 Workmanship and defects. Pipe or tubing and fittings shall be clear and free from cutting burrs and defects in structure or threading, and shall be thoroughly brushed, and chip and scale blown.

Defects in pipe or tubing or fittings shall not be repaired. Defective pipe, tubing or fittings shall be replaced. (See Section 2417.1.2.)

2414.8 Protective coating. Where in contact with material or atmosphere exerting a corrosive action, metallic piping and fittings coated with a corrosion-resistant material shall be used. External or internal coatings or linings used on piping or components shall not be considered as adding strength.

2414.9 Metallic pipe threads. Metallic pipe and fitting threads shall be taper pipe threads and shall comply with ASME B1.20.1.

2414.9.1 Damaged threads. Pipe with threads that are stripped, chipped, corroded or otherwise damaged shall not be used. If a weld opens during the operation of cutting or threading, that portion of the pipe shall not be used.

2414.9.2 Number of threads. Field threading of metallic pipe shall be in accordance with Table 2414.9.2.

TABLE 2414.9.2

SPECIFICATIONS FOR THREADING METALLIC PIPE

IRON PIPE SIZE (inches) APPROXIMATELENGTH OFTHREADED PORTION(inches) APPROXIMATE NO. OF THREADS TO BE CUT
1/2 3/4 10
3/4 3/4 10
1 7/8 10
11/4 1 11
11/2 1 11

For SI: 1 inch = 25.4 mm.

2414.9.3 Thread compounds. Thread (joint) compounds (pipe dope) shall be resistant to the action of liquefied petroleum gas or to any other chemical constituents of the gases to be conducted through the piping.

2414.10 Metallic piping joints and fittings. The type of piping joint used shall be suitable for the pressure-temperature conditions and shall be selected giving consideration to joint tightness and mechanical strength under the service conditions. The joint shall be able to sustain the maximum end force due to the internal pressure and any additional forces due to temperature expansion or contraction, vibration, fatigue, or to the weight of the pipe and its contents.

2414.10.1 Pipe joints. Pipe joints shall be threaded, flanged, brazed or welded. Where nonferrous pipe is brazed, the brazing materials shall have a melting point in excess of 1,000°F (538°C). Brazing alloys shall not contain more than 0.05 -percent phosphorus.

2414.10.2 Tubing joints. Tubing joints shall be made with approved gas tubing fittings or be brazed with a material having a melting point in excess of 1,000°F (538°C) or made with press-connect fittings complying with ANSI LC-4. Brazing alloys shall not contain more than 0.05 -percent phosphorus.

2414.10.3 Flared joints. Flared joints shall be used only in systems constructed from nonferrous pipe and tubing where experience or tests have demonstrated that the joint is suitable for the conditions and where provisions are made in the design to prevent separation of the joints.

2414.10.4 Metallic fittings. Metallic fittings, including valves, strainers and filters shall comply with the following:

1. Fittings used with steel or wrought-iron pipe shall be steel, brass, bronze, malleable iron, ductile iron or cast iron.

2. Fittings used with copper or brass pipe shall be copper, brass or bronze.

3. Cast-iron bushings shall be prohibited.

4. Special fittings. Fittings such as couplings, proprietary-type joints, saddle tees, gland-type compression fittings, and flared, flareless or compression-type tubing fittings shall be: used within the fitting manufacturer's pressure-temperature recommendations; used within the service conditions anticipated with respect to vibration, fatigue, thermal expansion or contraction; installed or braced to prevent separation of the joint by gas pressure or external physical damage; and shall be approved.

2414.11 Plastic piping, joints and fittings. Plastic pipe, tubing and fittings shall be joined in accordance with the manufacturers' instructions. Such joints shall comply with the following:

1. The joints shall be designed and installed so that the longitudinal pull-out resistance of the joints will be at least equal to the tensile strength of the plastic piping material.

2. Heat-fusion joints shall be made in accordance with qualified procedures that have been established and proven by test to produce gas-tight joints at least as strong as the pipe or tubing being joined. Joints shall be made with the joining method recommended by the pipe manufacturer. Heat fusion fittings shall be marked "ASTM D 2513."

3. Where compression-type mechanical joints are used, the gasket material in the fitting shall be compatible with the plastic piping and with the gas distributed by the system. An internal tubular rigid stiffener shall be used in conjunction with the fitting. The stiffener shall be flush with the end of the pipe or tubing and shall extend at least to the outside end of the compression fitting when installed. The stiffener shall be free of rough or sharp edges and shall not be a force fit in the plastic. Split tubular stiffeners shall not be used.

4. Plastic piping joints and fittings for use in liquefied petroleum gas piping systems shall be in accordance with NFPA 58.

SECTION 2415

PIPING SYSTEM INSTALLATION

2415.1 Prohibited locations. Piping shall not be installed in or through a ducted supply, return or exhaust, or a clothes chute, chimney or gas vent, dumbwaiter or elevator shaft. Piping installed downstream of the point of delivery shall not extend through any townhouse unit other than the unit served by such piping.

2415.2 Piping in solid partitions and walls. Concealed piping shall not be located in solid partitions and solid walls, unless installed in a chase or casing.

2415.3 Piping in concealed locations. Portions of a piping system installed in concealed locations shall not have unions, tubing fittings, right and left couplings, bushings, compression couplings, and swing joints made by combinations of fittings.

Exceptions:

1. Tubing joined by brazing.

2. Fittings listed for use in concealed locations.

2415.4 Underground penetrations prohibited. Gas piping shall not penetrate building foundation walls at any point below grade. Gas piping shall enter and exit a building at a point above grade and the annular space between the pipe and the wall shall be sealed.

2415.5 Protection against physical damage. In concealed locations, where piping other than black or galvanized steel is installed through holes or notches in wood studs, joists, rafters or similar members less than 11/2 inches (38 mm) from the nearest edge of the member, the pipe shall be protected by shield plates.

Protective steel shield plates having a minimum thickness of 0.0575 -inch ( 1.463 mm) (No. 16 Gage) shall cover the area of the pipe where the member is notched or bored and shall extend a minimum of 4 inches (102 mm) above sole plates, below top plates and to each side of a stud, joist or rafter.

2415.6 Piping in solid floors. Piping in solid floors shall be laid in channels in the floor and covered in a manner that will allow access to the piping with a minimum amount of damage to the building. Where such piping is subject to exposure to excessive moisture or corrosive substances, the piping shall be protected in an approved manner. As an alternative to installation in channels, the piping shall be installed in a conduit of Schedule 40 steel, wrought iron, PVC or ABS pipe in accordance with Section 2415.6.1 or 2415.6.2.

2415.6.1 Conduit with one end terminating outdoors. The conduit shall extend into an occupiable portion of the building and, at the point where the conduit terminates in the building, the space between the conduit and the gas piping shall be sealed to prevent the possible entrance of any gas leakage. The conduit shall extend not less than 2 inches (51 mm) beyond the point where the pipe emerges from the floor. If the end sealing is capable of withstanding the full pressure of the gas pipe, the conduit shall be designed for the same pressure as the pipe. Such conduit shall extend not less than 4 inches (102 mm) outside of the building, shall be vented above grade to the outdoors and shall be installed to prevent the entrance of water and insects.

2415.6.2 Conduit with both ends terminating indoors. Where the conduit originates and terminates within the same building, the conduit shall originate and terminate in an accessible portion of the building and shall not be sealed. The conduit shall extend not less than 2 inches (51 mm) beyond the point where the pipe emerges from the floor.

2415.7 Above-ground piping outdoors. All piping installed outdoors shall be elevated not less than 31/2 inches (152 mm) above ground and where installed across roof surfaces, shall be elevated not less than 31/2 inches (152 mm) above the roof surface. Piping installed above ground, outdoors, and installed across the surface of roofs shall be securely supported and located where it will be protected from physical damage. Where passing through an outside wall, the piping shall also be protected against corrosion by coating or wrapping with an inert material. Where piping is encased in a protective pipe sleeve, the annular space between the piping and the sleeve shall be sealed.

2415.8 Isolation. Metallic piping and metallic tubing that conveys fuel gas from an LP-gas storage container shall be provided with an approved dielectric fitting to electrically isolate the underground portion of the pipe or tube from the above ground portion that enters a building. Such dielectric fitting shall be installed aboveground outdoors.

2415.9 Protection against corrosion. Metallic pipe or tubing exposed to corrosive action, such as soil condition or moisture, shall be protected in an approved manner. Zinc coatings (galvanizing) shall not be deemed adequate protection for gas piping underground. Where dissimilar metals are joined underground, an insulating coupling or fitting shall be used. Piping shall not be laid in contact with cinders.

2415.9.1 Prohibited use. Uncoated threaded or socket welded joints shall not be used in piping in contact with soil or where internal or external crevice corrosion is known to occur.

2415.9.2 Protective coatings and wrapping. Pipe protective coatings and wrappings shall be approved for the application and shall be factory applied.

Exception: Where installed in accordance with the manufacturer's installation instructions, field application of coatings and wrappings shall be permitted for pipe nipples, fittings and locations where the factory coating or wrapping has been damaged or necessarily removed at joints.

2415.10 Minimum burial depth. Underground piping systems shall be installed a minimum depth of 12 inches (305 mm) below grade, except as provided for in Section 2415.10.1.

2415.10.1 Individual outside appliances. Individual lines to outside lights, grills or other appliances shall be installed a minimum of 8 inches (203 mm) below finished grade, provided that such installation is approved and is installed in locations not susceptible to physical damage.

2415.11 Trenches. The trench shall be graded so that the pipe has a firm, substantially continuous bearing on the bottom of the trench.

2415.12 Piping underground beneath buildings. Piping installed underground beneath buildings is prohibited except where the piping is encased in a conduit of wrought iron, plastic pipe, steel pipe or other approved conduit material designed to withstand the superimposed loads. The conduit shall be protected from corrosion in accordance with Section 2415.9 and shall be installed in accordance with Section 2415.12.1 or 2415.12.2.

2415.12.1 Conduit with one end terminating outdoors. The conduit shall extend into an occupiable portion of the building and, at the point where the conduit terminates in the building, the space between the conduit and the gas piping shall be sealed to prevent the possible entrance of any gas leakage. The conduit shall extend not less than 2 inches (51 mm) beyond the point where the pipe emerges from the floor. Where the end sealing is capable of withstanding the full pressure of the gas pipe, the conduit shall be designed for the same pressure as the pipe. Such conduit shall extend not less than 4 inches (102 mm) outside the building, shall be vented above grade to the outdoors and shall be installed so as to prevent the entrance of water and insects.

2415.12.2 Conduit with both ends terminating indoors. Where the conduit originates and terminates within the same building, the conduit shall originate and terminate in an accessible portion of the building and shall not be sealed. The conduit shall extend not less than 2 inches (51 mm) beyond the point where the pipe emerges from the floor.

2415.13 Outlet closures. Gas outlets that do not connect to appliances shall be capped gas tight.

Exception: Listed and labeled flush-mounted-type quick-disconnect devices and listed and labeled gas convenience outlets shall be installed in accordance with the manufacturer's installation instructions.

2415.14 Location of outlets. The unthreaded portion of piping outlets shall extend not less than l inch (25 mm) through finished ceilings and walls and where extending through floors, outdoor patios and slabs, shall not be less than 2 inches (51 mm) above them. The outlet fitting or piping shall be securely supported. Outlets shall not be placed behind doors. Outlets shall be located in the room or space where the appliance is installed.

Exception: Listed and labeled flush-mounted-type quick-disconnect devices and listed and labeled gas convenience outlets shall be installed in accordance with the manufacturer's installation instructions.

2415.15 Plastic pipe. The installation of plastic pipe shall comply with Sections 2415.15.1 through 2415.15.3.

2415.15.1 Limitations. Plastic pipe shall be installed outdoors underground only. Plastic pipe shall not be used within or under any building or slab or be operated at pressures greater than 100 psig (689 kPa) for natural gas or 30 psig (207 kPa) for LP-gas.

Exceptions:

1. Plastic pipe shall be permitted to terminate above ground outside of buildings where installed in premanufactured anodeless risers or service head adapter risers that are installed in accordance with the manufacturer's installation instructions.

2. Plastic pipe shall be permitted to terminate with a wall head adapter within buildings where the plastic pipe is inserted in a piping material for fuel gas use in buildings.

3. Plastic pipe shall be permitted under outdoor patio, walkway and driveway slabs provided that the burial depth complies with Section 2415.10.

2415.15.2 Connections. Connections outdoors and underground between metallic and plastic piping shall be made only with transition fittings conforming to ASTM D 2513 Category I or ASTM F 1973.

2415.15.3 Tracer. A yellow insulated copper tracer wire or other approved conductor shall be installed adjacent to underground nonmetallic piping. Access shall be provided to the tracer wire or the tracer wire shall terminate above ground at each end of the nonmetallic piping. The tracer wire size shall not be less than 18 AWG and the insulation type shall be suitable for direct burial.

2415.16 Prohibited devices. A device shall not be placed inside the piping or fittings that will reduce the cross-sectional area or otherwise obstruct the free flow of gas.

Exception: Approved gas filters.

2415.17 Testing of piping. Before any system of piping is put in service or concealed, it shall be tested to ensure that it is gas tight. Testing, inspection and purging of piping systems shall comply with Section 2417.

SECTION 2416

PIPING BENDS AND CHANGES IN DIRECTION

2416.1 General. Changes in direction of pipe shall be permitted to be made by the use of fittings, factory bends or field bends.

2416.2 Metallic pipe. Metallic pipe bends shall comply with the following:

1. Bends shall be made only with bending tools and procedures intended for that purpose.

2. All bends shall be smooth and free from buckling, cracks or other evidence of mechanical damage.

3. The longitudinal weld of the pipe shall be near the neutral axis of the bend.

4. Pipe shall not be bent through an arc of more than 90 degrees ( 1.6 rad).

5. The inside radius of a bend shall be not less than six times the outside diameter of the pipe.

2416.3 Plastic pipe. Plastic pipe bends shall comply with the following:

1. The pipe shall not be damaged and the internal diameter of the pipe shall not be effectively reduced.

2. Joints shall not be located in pipe bends.

3. The radius of the inner curve of such bends shall not be less than 25 times the inside diameter of the pipe.

4. Where the piping manufacturer specifies the use of special bending tools or procedures, such tools or procedures shall be used.

SECTION 2417

INSPECTION, TESTING AND PURGING

2417.1 General. Prior to acceptance and initial operation, all piping installations shall be inspected and pressure tested to determine that the materials, design, fabrication, and installation practices comply with the requirements of this code.

2417.1.1 Inspections. Inspection shall consist of visual examination, during or after manufacture, fabrication, assembly or pressure tests as appropriate.

2417.1.2 Repairs and additions. In the event repairs or additions are made after the pressure test, the affected piping shall be tested.

Minor repairs and additions are not required to be pressure tested provided that the work is inspected and connections are tested with a noncorrosive leak-detecting fluid or other approved leak-detecting methods.

2417.1.3 New branches. Where new branches are installed to new appliances, only the newly installed branches shall be required to be pressure tested. Connections between the new piping and the existing piping shall be tested with a noncorrosive leak-detecting fluid or other approved leak-detecting methods.

2417.1.4 Section testing. A piping system shall be permitted to be tested as a complete unit or in sections. Under no circumstances shall a valve in a line be used as a bulkhead between gas in one section of the piping system and test medium in an adjacent section, unless two valves are installed in series with a valved "tell-tale" located between these valves. A valve shall not be subjected to the test pressure unless it can be determined that the valve, including the valve closing mechanism, is designed to safely withstand the test pressure.

2417.1.5 Regulators and valve assemblies. Regulator and valve assemblies fabricated independently of the piping system in which they are to be installed shall be permitted to be tested with inert gas or air at the time of fabrication.

2417.2 Test medium. The test medium shall be air, nitrogen, carbon dioxide or an inert gas. Oxygen shall not be used.

2417.3 Test preparation. Pipe joints, including welds, shall be left exposed for examination during the test.

Exception: Covered or concealed pipe end joints that have been previously tested in accordance with this code.

2417.3.1 Expansion joints. Expansion joints shall be provided with temporary restraints, if required, for the additional thrust load under test.

2417.3.2 Equipment isolation. Equipment that is not to be included in the test shall be either disconnected from the piping or isolated by blanks, blind flanges or caps.

2417.3.3 Appliance and equipment disconnection. Where the piping system is connected to appliances or equipment designed for operating pressures of less than the test pressure, such appliances or equipment shall be isolated from the piping system by disconnecting them and capping the outlet(s).

2417.3.4 Valve isolation. Where the piping system is connected to appliances or equipment designed for operating pressures equal to or greater than the test pressure, such appliances or equipment shall be isolated from the piping system by closing the individual appliance or equipment shutoff valve(s).

2417.3.5 Testing precautions. All testing of piping systems shall be done with due regard for the safety of employees and the public during the test. Prior to testing, the interior of the pipe shall be cleared of all foreign material.

2417.4 Test pressure measurement. Test pressure shall be measured with a manometer or with a pressure-measuring device designed and calibrated to read, record, or indicate a pressure loss caused by leakage during the pressure test period. The source of pressure shall be isolated before the pressure tests are made. Mechanical gauges used to measure test pressures shall have a range such that the highest end of the scale is not greater than five times the test pressure.

2417.4.1 Test pressure. The test pressure to be used shall be not less than one and one-half times the proposed maximum working pressure, but not less than 3 psig (20 kPa gauge), irrespective of design pressure. Where the test pressure exceeds 125 psig (862 kPa gauge), the test pressure shall not exceed a value that produces a hoop stress in the piping greater than 50 percent of the specified minimum yield strength of the pipe.

2417.4.2 Test duration. The test duration shall be not less than 10 minutes.

2417.5 Detection of leaks and defects. The piping system shall withstand the test pressure specified without showing any evidence of leakage or other defects. Any reduction of test pressures as indicated by pressure gauges shall be deemed to indicate the presence of a leak unless such reduction can be readily attributed to some other cause.

2417.5.1 Detection methods. The leakage shall be located by means of an approved combustible gas detector, a noncorrosive leak detection fluid or an equivalent nonflammable solution. Matches, candles, open flames or other methods that could provide a source of ignition shall not be used.

2417.5.2 Corrections. Where leakage or other defects are located, the affected portion of the piping system shall be repaired or replaced and retested.

2417.6 Piping system and equipment leakage check. Leakage checking of systems and equipment shall be in accordance with Sections 2417.6.1 through 2417.6.4.

2417.6.1 Test gases. Fuel gas shall be permitted to be used for leak checks in piping systems that have been tested in accordance with Section 2417.

2417.6.2 Turning gas on. During the process of turning gas on into a system of new gas piping, the entire system shall be inspected to determine that there are no open fittings or ends and that all valves at unused outlets are closed and plugged or capped.

2417.6.3 Leak check. Immediately after the gas is turned on into a new system or into a system that has been initially restored after an interruption of service, the piping system shall be checked for leakage. Where leakage is indicated, the gas supply shall be shut off until the necessary repairs have been made.

2417.6.4 Placing appliances and equipment in operation. Appliances and equipment shall not be placed in operation until after the piping system has been checked for leakage and determined to be free of leakage and purged in accordance with Section 2417.7.2.

2417.7 Purging requirements. The purging of piping shall be in accordance with Sections 2417.7.1 through 2417.7.3

2417.7.1 Piping systems required to be purged outdoors. The purging of piping systems shall be in accordance with the provisions of Sections 2417.7.1.1 through 2417.7.1.4 where the piping system meets either of the following:

1.The design operating gas pressure is greater than 2 psig.

2.The piping being purged contains one or more sections of pie or tubing greater than 2 inches in nominal size and exceeding the lengths in Table 2417.7.1.1.

2417.7.1.1 Removal from service. Where existing gas piping is opened, the section that is opened shall be isolated from the gas supply and the line pressure vented in accordance with Section 2417.7.1.3. Where gas piping meeting the criteria of Table 2417.7.1.1 is removed from service, the residual fuel gas in the piping shall be displaced with an inert gas.

TABLE 2417.7.1.1

SIZE AND LENGTH OF PIPING

Nominal Pipe Size (inches) Length of Piping (feet)
2.5 >50
3 >30
4 >15
6 >10
8 or larger Any length

For SI units: 1 inch = 25.4 mm; 1 ft = 304.8 mm.

2417.7.1.2 Placing in operation. Where gas piping containing air and meeting the criteria of Table 2417.7.1.1 is placed in operation, the air in the piping shall first be displaced with an inert gas. The inert gas shall then be displaced with fuel gas in accordance with Section 2417.7.1.3.

2417.7.1.3 Outdoor discharge of purged gases. The open end of a piping system being pressure vented or purged shall discharge directly to an outdoor location. Purging operations shall comply with all of the following requirements.

1. The point of discharge shall be controlled with a shutoff valve.

2. The point of discharge shall be located at least 10 feet from sources of ignition, at least 10 feet from building openings and at least 25 feet from mechanical air intake openings.

3. During discharge, the open point of discharge shall be continuously attended and monitored with a combustible gas indicator that complies with Section 2417.7.1.4.

4. Purging operations introducing fuel gas shall be stopped when 90% fuel gas by volume is detected within the pipe.

5. Persons not involved in the purging operations shall be evacuated from all areas within 10 ft of the point of discharge.

2417.7.1.4 Combustible gas indicator. The combustible gas indicator used during purging operations shall be listed and shall be calibrated in accordance with the manufacturer's instructions and recommended schedule. The combustible gas indicator used for pipe discharge monitoring shall numerically display a volume scale from 0% to 100% with a resolution of not greater than 1% increments.

2417.7.2 Piping systems allowed to be purged indoors or outdoors. The purging of piping systems shall be in accordance with the provisions of Section 2417.7.2.1 where the piping system meets both of the following:

1. The design operating gas pressure is 2 psig or less.

2. The piping being purged is constructed entirely from pipe or tubing of 2 inch nominal size or smaller, or larger size pipe or tubing with lengths shorter than specified in Table 2417.7.1.1.

2417.7.2.1 Purging procedure. The piping system shall be purged in accordance with one or more of the following:

1. The piping shall be purged with fuel gas and shall discharge to the outdoors.

2. The piping shall be purged with fuel gas and shall discharge to the indoors or outdoors through an appliance burner not located in a combustion chamber. Such burner shall be provided with a continuous source of ignition.

3. The piping shall be purged with fuel gas and shall discharge to the indoors or outdoors through a burner that has a continuous source of ignition and that is designed for such purpose.

4. The piping shall be purged with fuel gas that is discharged to the indoors or outdoors, and the point of discharge shall be monitored with a listed combustible gas detector in accordance with 2417.7.2.2. Purging shall be stopped when fuel gas is detected.

5. The piping shall be purged by the gas supplier in accordance with written procedures.

2417.7.2.2 Combustible gas detector. The combustible gas detector used during purging operations shall be listed and shall be calibrated or tested in accordance with the manufacturer's instructions and recommended schedule. The combustible gas detector used for pipe discharge monitoring shall indicate the presence of fuel gas.

2417.7.3 Purging appliances and equipment. After the piping system has been placed in operation, appliances and equipment shall be purged before being placed into operation.

SECTION 2418

PIPING SUPPORT

2418.1 General. Piping shall be provided with support in accordance with Section 2418.2.

2418.2 Design and installation. Piping shall be supported with metal pipe hooks, metal pipe straps, metal bands, metal brackets, metal hangers or building structural components suitable for the size of piping, of adequate strength and quality, and located at intervals so as to prevent or damp out excessive vibration. Piping shall be anchored to prevent undue strains on connected appliances and shall not be supported by other piping. Pipe hangers and supports shall conform to the requirements of MSS SP-58 and shall be spaced in accordance with Section 2424. Supports, hangers and anchors shall be installed so as not to interfere with the free expansion and contraction of the piping between anchors. All parts of the supporting equipment shall be designed and installed so that they will not be disengaged by movement of the supported piping.

SECTION 2419

DRIPS AND SLOPED PIPING

2419.1 Slopes. Piping for other than dry gas conditions shall be sloped not less than 0.25 inch in 15 feet ( 6.4 mm in 4572 mm) to prevent traps.

2419.2 Drips. Where wet gas exists, a drip shall be provided at any point in the line of pipe where condensate could collect. A drip shall also be provided at the outlet of the meter and shall be installed so as to constitute a trap wherein an accumulation of condensate will shut off the flow of gas before the condensate will run back into the meter.

2419.3 Location of drips. Drips shall be provided with ready access to permit cleaning or emptying. A drip shall not be located where the condensate is subject to freezing.

2419.4 Sediment trap. Where a sediment trap is not incorporated as part of the appliance, a sediment trap shall be installed downstream of the appliance shutoff valve as close to the inlet of the appliance as practical. The sediment trap shall be either a tee fitting having a capped nipple of any length installed vertically in the bottom-most opening of the tee or other device approved as an effective sediment trap. Illuminating appliances, ranges, clothes dryers and outdoor grills need not be so equipped.

SECTION 2420

GAS SHUTOFF VALVES

2420.1 General. Piping systems shall be provided with shutoff valves in accordance with this section.

2420.1.1 Valve approval. Shutoff valves shall be of an approved type; shall be constructed of materials compatible with the piping; and shall comply with the standard that is applicable for the pressure and application, in accordance with Table 2420.1.1.

2420.1.2 Prohibited locations. Shutoff valves shall be prohibited in concealed locations and furnace plenums.

2420.1.3 Access to shutoff valves. Shutoff valves shall be located in places so as to provide access for operation and shall be installed so as to be protected from damage.

2420.2 Meter valve. Every meter shall be equipped with a shutoff valve located on the supply side of the meter.

2420.3 Individual buildings. In a common system serving more than one building, shutoff valves shall be installed outdoors at each building.

2420.4 MP regulator valves. A listed shutoff valve shall be installed immediately ahead of each MP regulator.

2420.5 Appliance shutoff valve. Each appliance shall be provided with a shutoff valve in accordance with Section 2420.5.1, 2420.5.2 or 2420.5.3.

2420.5.1 Located within same room. The shutoff valve shall be located in the same room as the appliance. The shutoff valve shall be within 6 feet (1829 mm) of the appliance, and shall be installed upstream of the union, connector or quick disconnect device it serves. Such shutoff valves shall be provided with access. Appliance shutoff valves located in the firebox of a fireplace shall be installed in accordance with the appliance manufacturer's instructions.

2420.5.2 Vented decorative appliances and room heaters. Shutoff valves for vented decorative appliances, room heaters and decorative appliances for installation in vented fireplaces shall be permitted to be installed in an area remote from the appliances where such valves are provided with ready access. Such valves shall be permanently identified and shall serve no other appliance. The piping from the shutoff valve to within 6 feet (1829 mm) of the appliance shall be designed, sized and installed in accordance with Sections 2412 through 2419.

2420.5.3 Located at manifold. Where the appliance shutoff valve is installed at a manifold, such shutoff valve shall be located within 50 feet (15 240 mm) of the appliance served and shall be readily accessible and permanently identified. The piping from the manifold to within 6 feet (1829 mm) of the appliance shall be designed, sized and installed in accordance with Sections 2412 through 2419.

SECTION 2421

FLOW CONTROLS

2421.1 Pressure regulators. A line pressure regulator shall be installed where the appliance is designed to operate at a lower pressure than the supply pressure. Line gas pressure regulators shall be listed as complying with ANSI Z 21.80. Access shall be provided to pressure regulators. Pressure regulators shall be protected from physical damage. Regulators installed on the exterior of the building shall be approved for outdoor installation.

2421.2 MP regulators. MP pressure regulators shall comply with the following:

1. The MP regulator shall be approved and shall be suitable for the inlet and outlet gas pressures for the application.

2. The MP regulator shall maintain a reduced outlet pressure under lockup (no-flow) conditions.

3. The capacity of the MP regulator, determined by published ratings of its manufacturer, shall be adequate to supply the appliances served.

4. The MP pressure regulator shall be provided with access. Where located indoors, the regulator shall be vented to the outdoors or shall be equipped with a leak-limiting device, in either case complying with Section 2421.3.

5. A tee fitting with one opening capped or plugged shall be installed between the MP regulator and its upstream shutoff valve. Such tee fitting shall be positioned to allow connection of a pressure measuring instrument and to serve as a sediment trap.

6. A tee fitting with one opening capped or plugged shall be installed not less than 10 pipe diameters downstream of the MP regulator outlet. Such tee fitting shall be positioned to allow connection of a pressure measuring instrument.

TABLE 2420.1.1

MANUAL GAS VALVE STANDARDS

VALVE STANDARDS APPLIANCE SHUTOFF VALVE APPLICATION UP TO 1/2 psig PRESSURE OTHER VALVE APPLICATIONS
UP TO 1/2 psig PRESSURE UP TO 2 psig PRESSURE UP TO 5 psig PRESSURE UP TO 125 psig PRESSURE
ANSI Z 21.15 X - - - -
CSA Requirement 3-88 X X Xa Xb -
ASME B 16.44 X X Xa Xb -
ASME B 16.33 X X X X X

For SI: 1 pound per square inch gauge = 6.895 kPa.

a. If labeled 2G.

b. If labeled 5G.

2421.3 Venting of regulators. Pressure regulators that require a vent shall be vented directly to the outdoors. The vent shall be designed to prevent the entry of insects, water and foreign objects.

Exception: A vent to the outdoors is not required for regulators equipped with and labeled for utilization with an approved vent-limiting device installed in accordance with the manufacturer's instructions.

2421.3.1 Vent piping. Vent piping for relief vents and breather vents shall be constructed of materials allowed for gas piping in accordance with Section 2414. Vent piping shall be not smaller than the vent connection on the pressure regulating device. Vent piping serving relief vents and combination relief and breather vents shall be run independently to the outdoors and shall serve only a single device vent. Vent piping serving only breather vents is permitted to be connected in a manifold arrangement where sized in accordance with an approved design that minimizes back pressure in the event of diaphragm rupture. Regulator vent piping shall not exceed the length specified in the regulator manufacturer's installation instructions.

SECTION 2422

APPLIANCE CONNECTIONS

2422.1 Connecting appliances. Appliances shall be connected to the piping system by one of the following:

1. Rigid metallic pipe and fittings.

2. Corrugated stainless steel tubing (CSST) where installed in accordance with the manufacturer's instructions.

3. Listed and labeled appliance connectors in compliance with ANSI Z 21.24 and installed in accordance with the manufacturer's installation instructions and located entirely in the same room as the appliance.

4. Listed and labeled quick-disconnect devices used in conjunction with listed and labeled appliance connectors.

5. Listed and labeled convenience outlets used in conjunction with listed and labeled appliance connectors.

6. Listed and labeled outdoor appliance connectors in compliance with ANSI Z 21.75 /CSA 6.27 and installed in accordance with the manufacturer's installation instructions.

2422.1.1 Protection from damage. Connectors and tubing shall be installed so as to be protected against physical damage.

2422.1.2 Connector installation. Appliance fuel connectors shall be installed in accordance with the manufacturer's instructions and Sections 24221.2.1 through 2422.1.2.4.

2422.1.2.1 Maximum length. Connectors shall not exceed 6 feet (1829 mm) in overall length. Measurement shall be made along the centerline of the connector. Only one connector shall be used for each appliance.

Exception: Rigid metallic piping used to connect an appliance to the piping system shall be permitted to have a total length greater than 6 feet (1829 mm) provided that the connecting pipe is sized as part of the piping system in accordance with Section 2413 and the location of the appliance shutoff valve complies with Section 2420.5.

2422.1.2.2 Minimum size. Connectors shall have the capacity for the total demand of the connected appliance.

2422.1.2.3 Prohibited locations and penetrations. Connectors shall not be concealed within, or extended through, walls, floors, partitions, ceilings or appliance housings.

Exceptions:

1. Connectors constructed of materials allowed for piping systems in accordance with Section 2414 shall be permitted to pass through walls, floors, partitions and ceilings where installed in accordance with Section 2420.5.2 or 2420.5.3.

2. Rigid steel pipe connectors shall be permitted to extend through openings in appliance housings.

3. Fireplace inserts that are factory equipped with grommets, sleeves or other means of protection in accordance with the listing of the appliance.

4. Semirigid tubing and listed connectors shall be permitted to extend through an opening in an appliance housing, cabinet or casing where the tubing or connector is protected against damage.

2422.1.2.4 Shutoff valve. A shutoff valve not less than the nominal size of the connector shall be installed ahead of the connector in accordance with Section 2420.5.

2422.1.3 Connection of gas engine-powered air conditioners. Internal combustion engines shall not be rigidly connected to the gas supply piping.

2422.1.4 Unions. A union fitting shall be provided for appliances connected by rigid metallic pipe. Such unions shall be accessible and located within 6 feet (1829 mm) of the appliance.

2422.1.5 Movable appliances. Where appliances are equipped with casters or are otherwise subject to periodic movement or relocation for purposes such as routine cleaning and maintenance, such appliances shall be connected to the supply system piping by means of an approved flexible connector designed and labeled for the application. Such flexible connectors shall be installed and protected against physical damage in accordance with the manufacturer's installation instructions.

2422.2 Suspended low-intensity infrared tube heaters. Suspended low-intensity infrared tube heaters shall be connected to the building piping system with a connector listed for the application complying with ANSI Z 21.24 /CGA 6.10. The connector shall be installed as specified by the tube heater manufacturer's instructions.

SECTION 2423

CNG GAS-DISPENSING SYSTEMS

2423.1 General. Motor fuel-dispensing facilities for CNG fuel shall be in accordance with Section 413 of the International Fuel Gas Code.

SECTION 2424

PIPING SUPPORT INTERVALS

2424.1 Interval of support. Piping shall be supported at intervals not exceeding the spacing specified in Table 2424.1. Spacing of supports for CSST shall be in accordance with the CSST manufacturer's instructions.

TABLE 2424.1

SUPPORT OF PIPING

STEEL PIPE,NOMINALSIZE OFPIPE (inches) SPACING OFSUPPORTS(feet) NOMINAL SIZEOF TUBINGSMOOTH-WALL(inch O.D.) SPACING OFSUPPORTS(feet)
1/2 6 1/2 4
3/4 or 1 8 5/8 or 3/4 6
11/4 or larger (horizontal) 10 7/8 or 1 (horizontal) 8
11/4 or larger (vertical) Every floor level 1 or larger (vertical) Every floor level

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

SECTION 2425

GENERAL

2425.1 Scope. This section shall govern the installation, maintenance, repair and approval of factory-built and masonry chimneys, chimney liners, vents and connectors serving gas-fired appliances.

2425.2 General. Every appliance shall discharge the products of combustion to the outdoors, except for appliances exempted by Section 2425.8.

2425.3 Masonry chimneys. Masonry chimneys shall be constructed in accordance with Section 2427.5 and Chapter 10.

2425.4 Minimum size of chimney or vent. Chimneys and vents shall be sized in accordance with Sections 2427 and 2428.

2425.5 Abandoned inlet openings. Abandoned inlet openings in chimneys and vents shall be closed by an approved method.

2425.6 Positive pressure. Where an appliance equipped with a mechanical forced draft system creates a positive pressure in the venting system, the venting system shall be designed for positive pressure applications.

2425.7 Connection to fireplace. Connection of appliances to chimney flues serving fireplaces shall be in accordance with Sections 2425.7.1 through 2425.7.3.

2425.7.1 Closure and access. A noncombustible seal shall be provided below the point of connection to prevent entry of room air into the flue. Means shall be provided for access to the flue for inspection and cleaning.

2425.7.2 Connection to factory-built fireplace flue. An appliance shall not be connected to a flue serving a factory-built fireplace unless the appliance is specifically listed for such installation. The connection shall be made in accordance with the appliance manufacturer's installation instructions.

2425.7.3 Connection to masonry fireplace flue. A connector shall extend from the appliance to the flue serving a masonry fireplace such that the flue gases are exhausted directly into the flue. The connector shall be accessible or removable for inspection and cleaning of both the connector and the flue. Listed direct connection devices shall be installed in accordance with their listing.

2425.8 Appliances not required to be vented. The following appliances shall not be required to be vented:

1. Ranges.

2. Built-in domestic cooking units listed and marked for optional venting.

3. Hot plates and laundry stoves.

4. Type 1 clothes dryers (Type 1 clothes dryers shall be exhausted in accordance with the requirements of Section 2439).

5. Refrigerators.

6. Counter appliances.

7. Room heaters listed for unvented use.

Where the appliances listed in Items 5 through 7 above are installed so that the aggregate input rating exceeds 20 Btu per hour per cubic foot (207 W/m3) of volume of the room or space in which such appliances are installed, one or more shall be provided with venting systems or other approved means for conveying the vent gases to the outdoor atmosphere so that the aggregate input rating of the remaining unvented appliances does not exceed 20 Btu per hour per cubic foot (207 W/m3). Where the room or space in which the appliance is installed is directly connected to another room or space by a doorway, archway or other opening of comparable size that cannot be closed, the volume of such adjacent room or space shall be permitted to be included in the calculations.

2425.9 Chimney entrance. Connectors shall connect to a masonry chimney flue at a point not less than 12 inches (305 mm) above the lowest portion of the interior of the chimney flue.

2425.10 Connections to exhauster. Appliance connections to a chimney or vent equipped with a power exhauster shall be made on the inlet side of the exhauster. Joints on the positive pressure side of the exhauster shall be sealed to prevent flue-gas leakage as specified by the manufacturer's installation instructions for the exhauster.

2425.11 Masonry chimneys. Masonry chimneys utilized to vent appliances shall be located, constructed and sized as specified in the manufacturer's installation instructions for the appliances being vented and Section 2427.

2425.12 Residential and low-heat appliances flue lining systems. Flue lining systems for use with residential-type and low-heat appliances shall be limited to the following:

1. Clay flue lining complying with the requirements of ASTM C 315 or equivalent. Clay flue lining shall be installed in accordance with Chapter 10.

2. Listed chimney lining systems complying with UL 1777.

3. Other approved materials that will resist, without cracking, softening or corrosion, flue gases and condensate at temperatures up to 1,800°F (982°C).

2425.13 Category I appliance flue lining systems. Flue lining systems for use with Category I appliances shall be limited to the following:

1. Flue lining systems complying with Section 2425.12.

2. Chimney lining systems listed and labeled for use with appliances with draft hoods and other Category I gas appliances listed and labeled for use with Type B vents.

2425.14 Category II, III and IV appliance venting systems. The design, sizing and installation of vents for Category II, III and IV appliances shall be in accordance with the appliance manufacturer's installation instructions.

2425.15 Existing chimneys and vents. Where an appliance is permanently disconnected from an existing chimney or vent, or where an appliance is connected to an existing chimney or vent during the process of a new installation, the chimney or vent shall comply with Sections 2425.15.1 through 2425.15.4.

2425.15.1 Size. The chimney or vent shall be resized as necessary to control flue gas condensation in the interior of the chimney or vent and to provide the appliance or appliances served with the required draft. For Category I appliances, the resizing shall be in accordance with Section 2426.

2425.15.2 Flue passageways. The flue gas passageway shall be free of obstructions and combustible deposits and shall be cleaned if previously used for venting a solid or liquid fuel-burning appliance or fireplace. The flue liner, chimney inner wall or vent inner wall shall be continuous and shall be free of cracks, gaps, perforations, or other damage or deterioration that would allow the escape of combustion products, including gases, moisture and creosote.

2425.15.3 Cleanout. Masonry chimney flues shall be provided with a cleanout opening having a minimum height of 6 inches (152 mm). The upper edge of the opening shall be located not less than 6 inches (152 mm) below the lowest chimney inlet opening. The cleanout shall be provided with a tight-fitting, noncombustible cover.

2425.15.4 Clearances. Chimneys and vents shall have airspace clearance to combustibles in accordance with Chapter 10 and the chimney or vent manufacturer's installation instructions.

Exception: Masonry chimneys without the required air-space clearances shall be permitted to be used if lined or relined with a chimney lining system listed for use in chimneys with reduced clearances in accordance with UL 1777. The chimney clearance shall be not less than that permitted by the terms of the chimney liner listing and the manufacturer's instructions.

2425.15.4.1 Fireblocking. Noncombustible fireblocking shall be provided in accordance with Chapter 10.

SECTION 2426

VENTS

2426.1 General. All vents, except as provided in Section 2427.7, shall be listed and labeled. Type B and BW vents shall be tested in accordance with UL 441. Type L vents shall be tested in accordance with UL 641. Vents for Category II and III appliances shall be tested in accordance with UL 1738. Plastic vents for Category IV appliances shall not be required to be listed and labeled where such vents are as specified by the appliance manufacturer and are installed in accordance with the appliance manufacturer's installation instructions.

2426.2 Connectors required. Connectors shall be used to connect appliances to the vertical chimney or vent, except where the chimney or vent is attached directly to the appliance. Vent connector size, material, construction and installation shall be in accordance with Section 2427.

2426.3 Vent application. The application of vents shall be in accordance with Table 2427.4.

2426.4 Insulation shield. Where vents pass through insulated assemblies, an insulation shield constructed of steel having a minimum thickness of 0.0187 inch ( 0.4712 mm) (26 gage) shall be installed to provide clearance between the vent and the insulation material. The clearance shall not be less than the clearance to combustibles specified by the vent manufacturer's installation instructions. Where vents pass through attic space, the shield shall terminate not less than 2 inches (51 mm) above the insulation materials and shall be secured in place to prevent displacement. Insulation shields provided as part of a listed vent system shall be installed in accordance with the manufacturer's installation instructions.

2426.5 Installation. Vent systems shall be sized, installed and terminated in accordance with the vent and appliance manufacturer's installation instructions and Section 2427.

2426.6 Support of vents. All portions of vents shall be adequately supported for the design and weight of the materials employed.

2426.7 Protection against physical damage. In concealed locations, where a vent is installed through holes or notches in studs, joists, rafters or similar members less than 11/2 inches (38 mm) from the nearest edge of the member, the vent shall be protected by shield plates. Protective steel shield plates having a minimum thickness of 0.0575 -inch ( 1.463 mm) (16 gage) shall cover the area of the vent where the member is notched or bored and shall extend a minimum of 4 inches (102 mm) above sole plates, below top plates and to each side of a stud, joist or rafter.

SECTION 2427

VENTING OF APPLIANCES

2427.1 General. This section recognizes that the choice of venting materials and the methods of installation of venting systems are dependent on the operating characteristics of the appliance being vented. The operating characteristics of vented appliances can be categorized with respect to:

(1) positive or negative pressure within the venting system; and (2) whether or not the appliance generates flue or vent gases that might condense in the venting system. See Section 2403 for the definitions of these vented appliance categories.

2427.2 Venting systems required. Except as permitted in Sections 2427.2.1, 2427.2.2 and 2425.8, all appliances shall be connected to venting systems.

2427.2.1 Direct-vent appliances. Listed direct-vent appliances shall be installed in accordance with the manufacturer's instructions and Section 2427.8, Item 3.

2427.2.2 Appliances with integral vents. Appliances incorporating integral venting means shall be considered properly vented where installed in accordance with the manufacturer's instructions and Section 2427.8, Items 1 and 2.

2427.3 Design and construction. A venting system shall be designed and constructed so as to develop a positive flow adequate to convey flue or vent gases to the outdoors.

2427.3.1 Appliance draft requirements. A venting system shall satisfy the draft requirements of the appliance in accordance with the manufacturer's instructions.

2427.3.2 Design and construction. Appliances required to be vented shall be connected to a venting system designed and installed in accordance with the provisions of Sections 2427.4 through 2427.16.

2427.3.3 Mechanical draft systems. Mechanical draft systems shall comply with the following:

1. Mechanical draft systems shall be listed and shall be installed in accordance with the manufacturer's installation instructions for both the appliance and the mechanical draft system.

2. Appliances, except incinerators, requiring venting shall be permitted to be vented by means of mechanical draft systems of either forced or induced draft design.

3. Forced draft systems and all portions of induced draft systems under positive pressure during operation shall be designed and installed so as to prevent leakage of flue or vent gases into a building.

4. Vent connectors serving appliances vented by natural draft shall not be connected into any portion of mechanical draft systems operating under positive pressure.

5. Where a mechanical draft system is employed, provisions shall be made to prevent the flow of gas to the main burners when the draft system is not performing so as to satisfy the operating requirements of the appliance for safe performance.

6. The exit terminals of mechanical draft systems shall be not less than 7 feet (2134 mm) above finished ground level where located adjacent to public walkways and shall be located as specified in Section 2427.8, Items 1 and 2.

2427.3.4 Air ducts and furnace plenums. Venting systems shall not extend into or pass through any fabricated air duct or furnace plenum

2427.3.5 Above-ceiling air-handling spaces. Where a venting system passes through an above-ceiling air-handling space or other nonducted portion of an air-handling system, the venting system shall conform to one of the following requirements:

1. The venting system shall be a listed special gas vent; other venting system serving a Category III or Category IV appliance; or other positive pressure vent, with joints sealed in accordance with the appliance or vent manufacturer's instructions.

2. The venting system shall be installed such that fittings and joints between sections are not installed in the above-ceiling space.

3. The venting system shall be installed in a conduit or enclosure with sealed joints separating the interior of the conduit or enclosure from the ceiling space.

2427.4 Type of venting system to be used. The type of venting system to be used shall be in accordance with Table 2427.4.

2427.4.1 Plastic piping. Plastic piping used for venting appliances listed for use with such venting materials shall be approved.

2427.4.1.1 (IFGS) Plastic vent joints. Plastic pipe and fittings used to vent appliances shall be installed in accordance with the appliance manufacturer's installation instructions. Where a primer is required, it shall be of a contrasting color.

2427.4.2 Special gas vent. Special gas vent shall be listed and installed in accordance with the special gas vent manufacturer's installation instructions.

2427.5 Masonry, metal and factory-built chimneys. Masonry, metal and factory-built chimneys shall comply with Sections 2427.5.1 through 2427.5.9.

2427.5.1 Factory-built chimneys. Factory-built chimneys shall be installed in accordance with the manufacturer's installation instructions. Factory-built chimneys used to vent appliances that operate at a positive vent pressure shall be listed for such application.

2427.5.2 Masonry chimneys. Masonry chimneys shall be built and installed in accordance with NFPA 211 and shall be lined with approved clay flue lining, a listed chimney lining system or other approved material that will resist corrosion, erosion, softening or cracking from vent gases at temperatures up to 1,800°F (982°C).

Exception: Masonry chimney flues serving listed gas appliances with draft hoods, Category I appliances and other gas appliances listed for use with Type B vents shall be permitted to be lined with a chimney lining system specifically listed for use only with such appliances. The liner shall be installed in accordance with the liner manufacturer's installation instructions. A permanent identifying label shall be attached at the point where the connection is to be made to the liner. The label shall read: "This chimney liner is for appliances that burn gas only. Do not connect to solid or liquid fuel-burning appliances or incinerators."

TABLE 2427.4

TYPE OF VENTING SYSTEM TO BE USED

APPLIANCES TYPE OF VENTING SYSTEM
Listed Category I appliances Listed appliances equipped with draft hood Appliances listed for use with Type B gas vent Type B gas vent (Section 2427.6 ) Chimney (Section 2427.5 ) Single-wall metal pipe (Section 2427.7 ) Listed chimney lining system for gas venting (Section 2427.5.2) Special gas vent listed for these appliances (Section 2427.4.2)
Listed vented wall furnaces Type B-W gas vent (Sections 2427.6, 2436)
Category II appliances As specified or furnished by manufacturers of listed appliances (Sections 2427.4.1, 2427.4.2)
Category III appliances As specified or furnished by manufacturers of listed appliances (Sections 2427.4.1, 2427.4.2)
Category IV appliances As specified or furnished by manufacturers of listed appliances (Sections 2427.4.1, 2427.4.2)
Unlisted appliances Chimney (Section 2427.5 )
Decorative appliances in vented fireplaces Chimney
Direct-vent appliances See Section 2427.2.1
Appliances with integral vent See Section 2427.2.2

2427.5.3 Chimney termination. Chimneys for residential-type or low-heat appliances shall extend at least 3 feet (914 mm) above the highest point where they pass through a roof of a building and at least 2 feet (610 mm) higher than any portion of a building within a horizontal distance of 10 feet (3048 mm) (see Figure 2427.5.3). Chimneys for medium-heat appliances shall extend at least 10 feet (3048 mm) higher than any portion of any building within 25 feet (7620 mm). Chimneys shall extend at least 5 feet (1524 mm) above the highest connected appliance draft hood outlet or flue collar. Decorative shrouds shall not be installed at the termination of factory-built chimneys except where such shrouds are listed and labeled for use with the specific factory-built chimney system and are installed in accordance with the manufacturer's installation instructions.

2427.5.4 Size of chimneys. The effective area of a chimney venting system serving listed appliances with draft hoods, Category I appliances, and other appliances listed for use with Type B vents shall be determined in accordance with one of the following methods:

1. The provisions of Section 2428.

2. For sizing an individual chimney venting system for a single appliance with a draft hood, the effective areas of the vent connector and chimney flue shall be not less than the area of the appliance flue collar or draft hood outlet, nor greater than seven times the draft hood outlet area.

3. For sizing a chimney venting system connected to two appliances with draft hoods, the effective area of the chimney flue shall be not less than the area of the larger draft hood outlet plus 50 percent of the area of the smaller draft hood outlet, nor greater than seven times the smallest draft hood outlet area.

4. Chimney venting systems using mechanical draft shall be sized in accordance with approved engineering methods.

5. Other approved engineering methods.

2427.5.5 Inspection of chimneys. Before replacing an existing appliance or connecting a vent connector to a chimney, the chimney passageway shall be examined to ascertain that it is clear and free of obstructions and it shall be cleaned if previously used for venting solid or liquid fuel-burning appliances or fireplaces.

2427.5.5.1 Chimney lining. Chimneys shall be lined in accordance with NFPA 211.

Exception: Where an existing chimney complies with Sections 2427.5.5 through 2427.5.5.3 and its sizing is in accordance with Section 2427.5.4, its continued use shall be allowed where the appliance vented by that chimney is replaced by an appliance of similar type, input rating and efficiency.

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2427.5.5.2 Cleanouts. Cleanouts shall be examined to determine that they will remain tightly closed when not in use.

2427.5.5.3 Unsafe chimneys. Where inspection reveals that an existing chimney is not safe for the intended application, it shall be repaired, rebuilt, lined, relined or replaced with a vent or chimney to conform to NFPA 211 and it shall be suitable for the appliances to be vented.

2427.5.6 Chimneys serving appliances burning other fuels. Chimneys serving appliances burning other fuels shall comply with Sections 2427.5.6.1 through 2427.5.6.4.

2427.5.6.1 Solid fuel-burning appliances. An appliance shall not be connected to a chimney flue serving a separate appliance designed to burn solid fuel.

2427.5.6.2 Liquid fuel-burning appliances. Where one chimney flue serves gas appliances and liquid fuel-burning appliances, the appliances shall be connected through separate openings or shall be connected through a single opening where joined by a suitable fitting located as close as practical to the chimney. Where two or more openings are provided into one chimney flue, they shall be at different levels. Where the appliances are automatically controlled, they shall be equipped with safety shutoff devices.

2427.5.6.3 Combination gas-and solid fuel-burning appliances. A combination gas-and solid fuel-burning appliance equipped with a manual reset device to shut off gas to the main burner in the event of sustained backdraft or flue gas spillage shall be permitted to be connected to a single chimney flue. The chimney flue shall be sized to properly vent the appliance.

2427.5.6.4 Combination gas-and oil fuel-burning appliances. A listed combination gas-and oil fuel-burning appliance shall be permitted to be connected to a single chimney flue. The chimney flue shall be sized to properly vent the appliance.

2427.5.7 Support of chimneys. All portions of chimneys shall be supported for the design and weight of the materials employed. Factory-built chimneys shall be supported and spaced in accordance with the manufacturer's installation instructions.

2427.5.8 Cleanouts. Where a chimney that formerly carried flue products from liquid or solid fuel-burning appliances is used with an appliance using fuel gas, an accessible cleanout shall be provided. The cleanout shall have a tight-fitting cover and be installed so its upper edge is at least 6 inches (152 mm) below the lower edge of the lowest chimney inlet opening.

2427.5.9 Space surrounding lining or vent. The remaining space surrounding a chimney liner, gas vent, special gas vent or plastic piping installed within a masonry chimney flue shall not be used to vent another appliance. The insertion of another liner or vent within the chimney as provided in this code and the liner or vent manufacturer's instructions shall not be prohibited.

The remaining space surrounding a chimney liner, gas vent, special gas vent or plastic piping installed within a masonry, metal or factory-built chimney shall not be used to supply combustion air. Such space shall not be prohibited from supplying combustion air to direct-vent appliances designed for installation in a solid fuel-burning fireplace and installed in accordance with the manufacturer's installation instructions.

2427.6 Gas vents. Gas vents shall comply with Sections 2427.6.1 through 2427.6.11. (See Section 2403, Definitions.)

2427.6.1 Installation, general. Gas vents shall be installed in accordance with the terms of their listings and the manufacturer's instructions.

2427.6.2 Type B-W vent capacity. A Type B-W gas vent shall have a listed capacity not less than that of the listed vented wall furnace to which it is connected.

2427.6.3 Gas vent termination. A gas vent shall terminate in accordance with one of the following:

1. Gas vents that are 12 inches (305 mm) or less in size and located not less than 8 feet (2438 mm) from a vertical wall or similar obstruction shall terminate above the roof in accordance with Figure 2427.6.3.

2. Gas vents that are over 12 inches (305 mm) in size or are located less than 8 feet (2438 mm) from a vertical wall or similar obstruction shall terminate not less than 2 feet (610 mm) above the highest point where they pass through the roof and not less than 2 feet (610 mm) above any portion of a building within 10 feet (3048 mm) horizontally.

3. As provided for direct-vent systems in Section 2427.2.1.

4. As provided for appliances with integral vents in Section 2427.2.2.

5. As provided for mechanical draft systems in Section 2427.3.3.

2427.6.3.1 Decorative shrouds. Decorative shrouds shall not be installed at the termination of gas vents except where such shrouds are listed for use with the specific gas venting system and are installed in accordance with manufacturer's installation instructions.

2427.6.4 Minimum height. A Type B or L gas vent shall terminate at least 5 feet (1524 mm) in vertical height above the highest connected appliance draft hood or flue collar. A Type B-W gas vent shall terminate at least 12 feet (3658 mm) in vertical height above the bottom of the wall furnace.

2427.6.5 Roof terminations. Gas vents shall extend through the roof flashing, roof jack or roof thimble and terminate with a listed cap or listed roof assembly.

2427.6.6 Forced air inlets. Gas vents shall terminate not less than 3 feet (914 mm) above any forced air inlet located within 10 feet (3048 mm).

2427.6.7 Exterior wall penetrations. A gas vent extending through an exterior wall shall not terminate adjacent to the wall or below eaves or parapets, except as provided in Sections 2427.2.1 and 2427.3.3.

2427.6.8 Size of gas vents. Venting systems shall be sized and constructed in accordance with Section 2428 or other approved engineering methods and the gas vent and appliance manufacturer's installation instructions.

2427.6.8.1 Category I appliances. The sizing of natural draft venting systems serving one or more listed appliances equipped with a draft hood or appliances listed for use with Type B gas vent, installed in a single story of a building, shall be in accordance with one of the following methods:

1. The provisions of Section 2428.

2. For sizing an individual gas vent for a single, draft-hood-equipped appliance, the effective area of the vent connector and the gas vent shall be not less than the area of the appliance draft hood outlet, nor greater than seven times the draft hood outlet area.

3. For sizing a gas vent connected to two appliances with draft hoods, the effective area of the vent shall be not less than the area of the larger draft hood outlet plus 50 percent of the area of the smaller draft hood outlet, nor greater than seven times the smaller draft hood outlet area.

4. Approved engineering practices.

2427.6.8.2 Vent offsets. Type B and L vents sized in accordance with Item 2 or 3 of Section 2427.6.8.1 shall extend in a generally vertical direction with offsets not exceeding 45 degrees ( 0.79 rad), except that a vent system having not more than one 60-degree ( 1.04 rad) offset shall be permitted. Any angle greater than 45 degrees ( 0.79 rad) from the vertical is considered horizontal. The total horizontal distance of a vent plus the horizontal vent connector serving draft hood-equipped appliances shall be not greater than 75 percent of the vertical height of the vent.

2427.6.8.3 Category II, III and IV appliances. The sizing of gas vents for Category II, III and IV appliances shall be in accordance with the appliance manufacturer's instructions.

2427.6.8.4 Mechanical draft. Chimney venting systems using mechanical draft shall be sized in accordance with approved engineering methods.

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ROOF SLOPE H (minimum) ft
Flat to 6/12 1.0
Over 6/12 to 7/12 1.25
Over 7/12 to 8/12 1.5
Over 8/12 to 9/12 2.0
Over 9/12 to 10/12 2.5
Over 10/12 to 11/12 3.25
Over 11/12 to 12/12 4.0
Over 12/12 to 14/12 5.0
Over 14/12 to 16/12 6.0
Over 16/12 to 18/12 7.0
Over 18/12 to 20/12 7.5
Over 20/12 to 21/12 8.0

For SI: 1 foot = 304.8 mm.

FIGURE 2427.6.3

GAS VENT TERMINATION LOCATIONS FOR LISTED CAPS 12 INCHES OR LESS IN SIZE AT LEAST 8 FEET FROM A VERTICAL WALL

2427.6.9 Support of gas vents. Gas vents shall be supported and spaced in accordance with the manufacturer's installation instructions.

2427.6.10 Marking. In those localities where solid and liquid fuels are used extensively, gas vents shall be permanently identified by a label attached to the wall or ceiling at a point where the vent connector enters the gas vent. The determination of where such localities exist shall be made by the building official. The label shall read:

"This gas vent is for appliances that burn gas. Do not connect to solid or liquid fuel-burning appliances or incinerators."

2427.6.11 Fastener penetrations. Screws, rivets and other fasteners shall not penetrate the inner wall of double-wall gas vents, except at the transition from an appliance draft hood outlet, a flue collar or a single-wall metal connector to a double-wall vent.

2427.7 Single-wall metal pipe. Single-wall metal pipe vents shall comply with Sections 2427.7.1 through 2427.7.13.

2427.7.1 Construction. Single-wall metal pipe shall be constructed of galvanized sheet steel not less than 0.0304 inch ( 0.7 mm) thick, or other approved, noncombustible, corrosion-resistant material.

2427.7.2 Cold climate. Uninsulated single-wall metal pipe shall not be used outdoors for venting appliances in regions where the 99-percent winter design temperature is below 32ºF (0ºC).

2427.7.3 Termination. Single-wall metal pipe shall terminate at least 5 feet (1524 mm) in vertical height above the highest connected appliance draft hood outlet or flue collar. Single-wall metal pipe shall extend at least 2 feet (610 mm) above the highest point where it passes through a roof of a building and at least 2 feet (610 mm) higher than any portion of a building within a horizontal distance of 10 feet (3048 mm) (see Figure 2427.5.3). An approved cap or roof assembly shall be attached to the terminus of a single-wall metal pipe (see also Section 2427.7.9, Item 3).

2427.7.4 Limitations of use. Single-wall metal pipe shall be used only for runs directly from the space in which the appliance is located through the roof or exterior wall to the outdoor atmosphere.

2427.7.5 Roof penetrations. A pipe passing through a roof shall extend without interruption through the roof flashing, roof jack, or roof thimble. Where a single-wall metal pipe passes through a roof constructed of combustible material, a noncombustible, nonventilating thimble shall be used at the point of passage. The thimble shall extend at least 18 inches (457 mm) above and 6 inches (152 mm) below the roof with the annular space open at the bottom and closed only at the top. The thimble shall be sized in accordance with Section 2427.7.7.

2427.7.6 Installation. Single-wall metal pipe shall not originate in any unoccupied attic or concealed space and shall not pass through any attic, inside wall, concealed space, or floor. The installation of a single-wall metal pipe through an exterior combustible wall shall comply with Section 2427.7.7. Single-wall metal pipe used for venting an incinerator shall be exposed and readily examinable for its full length and shall have suitable clearances maintained.

2427.7.7 Single-wall penetrations of combustible walls. Single-wall metal pipe shall not pass through a combustible exterior wall unless guarded at the point of passage by a ventilated metal thimble not smaller than the following:

1. For listed appliances equipped with draft hoods and appliances listed for use with Type B gas vents, the thimble shall be not less than 4 inches (102 mm) larger in diameter than the metal pipe. Where there is a run of not less than 6 feet (1829 mm) of metal pipe in the open between the draft hood outlet and the thimble, the thimble shall be permitted to be not less than 2 inches (51 mm) larger in diameter than the metal pipe.

2. For unlisted appliances having draft hoods, the thimble shall be not less than 6 inches (152 mm) larger in diameter than the metal pipe.

3. For residential and low-heat appliances, the thimble shall be not less than 12 inches (305 mm) larger in diameter than the metal pipe.

Exception: In lieu of thimble protection, all combustible material in the wall shall be removed a sufficient distance from the metal pipe to provide the specified clearance from such metal pipe to combustible material. Any material used to close up such opening shall be noncombustible.

2427.7.8 Clearances. Minimum clearances from single-wall metal pipe to combustible material shall be in accordance with Table 2427.10.5. The clearance from single-wall metal pipe to combustible material shall be permitted to be reduced where the combustible material is protected as specified for vent connectors in Table 2409.2.

2427.7.9 Size of single-wall metal pipe. A venting system constructed of single-wall metal pipe shall be sized in accordance with one of the following methods and the appliance manufacturer's instructions:

1. For a draft-hood-equipped appliance, in accordance with Section 2428.

2. For a venting system for a single appliance with a draft hood, the areas of the connector and the pipe each shall be not less than the area of the appliance flue collar or draft hood outlet, whichever is smaller. The vent area shall not be greater than seven times the draft hood outlet area.

3. Other approved engineering methods.

2427.7.10 Pipe geometry. Any shaped single-wall metal pipe shall be permitted to be used, provided that its equivalent effective area is equal to the effective area of the round pipe for which it is substituted, and provided that the minimum internal dimension of the pipe is not less than 2 inches (51 mm).

2427.7.11 Termination capacity. The vent cap or a roof assembly shall have a venting capacity not less than that of the pipe to which it is attached.

2427.7.12 Support of single-wall metal pipe. All portions of single-wall metal pipe shall be supported for the design and weight of the material employed.

2427.7.13 Marking. Single-wall metal pipe shall comply with the marking provisions of Section 2427.6.10.

2427.8 Venting system termination location. The location of venting system terminations shall comply with the following (see Appendix C):

1. A mechanical draft venting system shall terminate at least 3 feet (914 mm) above any forced-air inlet located within 10 feet (3048 mm).

Exceptions:

1. This provision shall not apply to the combustion air intake of a direct-vent appliance.

2. This provision shall not apply to the separation of the integral outdoor air inlet and flue gas discharge of listed outdoor appliances.

2. A mechanical draft venting system, excluding direct-vent appliances, shall terminate at least 4 feet (1219 mm) below, 4 feet (1219 mm) horizontally from, or 1 foot (305 mm) above any door, operable window, or gravity air inlet into any building. The bottom of the vent terminal shall be located at least 12 inches (305 mm) above finished ground level.

3. The vent terminal of a direct-vent appliance with an input of 10,000 Btu per hour (3 kW) or less shall be located at least 6 inches (152 mm) from any air opening into a building, and such an appliance with an input over 10,000 Btu per hour (3 kW) but not over 50,000 Btu per hour ( 14.7 kW) shall be installed with a 9-inch (230 mm) vent termination clearance, and an appliance with an input over 50,000 Btu/h ( 14.7 kW) shall have at least a 12-inch (305 mm) vent termination clearance. The bottom of the vent terminal and the air intake shall be located at least 12 inches (305 mm) above finished ground level.

4. Through-the-wall vents for Category II and IV appliances and noncategorized condensing appliances shall not terminate over public walkways or over an area where condensate or vapor could create a nuisance or hazard or could be detrimental to the operation of regulators, relief valves, or other equipment. Where local experience indicates that condensate is a problem with Category I and III appliances, this provision shall also apply. Drains for condensate shall be installed in accordance with the manufacturer's installation instructions.

2427.9 Condensation drainage. Provisions shall be made to collect and dispose of condensate from venting systems serving Category II and IV appliances and noncategorized condensing appliances in accordance with Section 2427.8, Item 4. Where local experience indicates that condensation is a problem, provision shall be made to drain off and dispose of condensate from venting systems serving Category I and III appliances in accordance with Section 2427.8, Item 4.

2427.10 Vent connectors for Category I appliances. Vent connectors for Category I appliances shall comply with Sections 2427.10.1 through 2427.10.14.

2427.10.1 Where required. A vent connector shall be used to connect an appliance to a gas vent, chimney or single-wall metal pipe, except where the gas vent, chimney or single-wall metal pipe is directly connected to the appliance.

2427.10.2 Materials. Vent connectors shall be constructed in accordance with Sections 2427.10.2.1 through 2427.10.2.4.

2427.10.2.1 General. A vent connector shall be made of noncombustible corrosion-resistant material capable of withstanding the vent gas temperature produced by the appliance and of sufficient thickness to withstand physical damage.

2427.10.2.2 Vent connectors located in unconditioned areas. Where the vent connector used for an appliance having a draft hood or a Category I appliance is located in or passes through attics, crawl spaces or other unconditioned spaces, that portion of the vent connector shall be listed Type B, Type L or listed vent material having equivalent insulation properties.

Exception: Single-wall metal pipe located within the exterior walls of the building in areas having a local 99-percent winter design temperature of 5°F (-15°C) or higher shall be permitted to be used in unconditioned spaces other than attics and crawl spaces.

2427.10.2.3 Residential-type appliance connectors. Where vent connectors for residential-type appliances are not installed in attics or other unconditioned spaces, connectors for listed appliances having draft hoods, appliances having draft hoods and equipped with listed conversion burners and Category I appliances shall be one of the following:

1. Type B or L vent material;

2. Galvanized sheet steel not less than 0.018 inch ( 0.46 mm) thick;

3. Aluminum (1100 or 3003 alloy or equivalent) sheet not less than 0.027 inch ( 0.69 mm) thick;

4. Stainless steel sheet not less than 0.012 inch ( 0.31 mm) thick;

5. Smooth interior wall metal pipe having resistance to heat and corrosion equal to or greater than that of Item 2, 3 or 4 above; or

6. A listed vent connector.

Vent connectors shall not be covered with insulation.

Exception: Listed insulated vent connectors shall be installed in accordance with the manufacturer's installation instructions.

2427.10.2.4 Low-heat appliance. A vent connector for a nonresidential, low-heat appliance shall be a factory-built chimney section or steel pipe having resistance to heat and corrosion equivalent to that for the appropriate galvanized pipe as specified in Table 2427.10.2.4. Factory-built chimney sections shall be joined together in accordance with the chimney manufacturer's instructions.

TABLE 2427.10.2.4

MINIMUM THICKNESS FOR GALVANIZED STEEL VENT CONNECTORS FOR LOW-HEAT APPLIANCES

DIAMETER OF CONNECTOR (inches) MINIMUM THICKNESS (inch)
Less than 6 0.019
6 to less than 10 0.023
10 to 12 inclusive 0.029
14 to 16 inclusive 0.034
Over 16 0.056

For SI: 1 inch = 25.4 mm.

2427.10.3 Size of vent connector. Vent connectors shall be sized in accordance with Sections 2427.10.3.1 through 2427.3.5.

2427.10.3.1 Single draft hood and fan-assisted. A vent connector for an appliance with a single draft hood or for a Category I fan-assisted combustion system appliance shall be sized and installed in accordance with Section 2428 or other approved engineering methods.

2427.10.3.2 Multiple draft hood. For a single appliance having more than one draft hood outlet or flue collar, the manifold shall be constructed according to the instructions of the appliance manufacturer. Where there are no instructions, the manifold shall be designed and constructed in accordance with approved engineering practices. As an alternate method, the effective area of the manifold shall equal the combined area of the flue collars or draft hood outlets and the vent connectors shall have a minimum 1-foot (305 mm) rise.

2427.10.3.3 Multiple appliances. Where two or more appliances are connected to a common vent or chimney, each vent connector shall be sized in accordance with Section 2428 or other approved engineering methods.

As an alternative method applicable only when all of the appliances are draft hood equipped, each vent connector shall have an effective area not less than the area of the draft hood outlet of the appliance to which it is connected.

2427.10.3.4 Common connector/manifold. Where two or more appliances are vented through a common vent connector or vent manifold, the common vent connector or vent manifold shall be located at the highest level consistent with available headroom and the required clearance to combustible materials and shall be sized in accordance with Section 2428 or other approved engineering methods.

As an alternate method applicable only where there are two draft hood-equipped appliances, the effective area of the common vent connector or vent manifold and all junction fittings shall be not less than the area of the larger vent connector plus 50 percent of the area of the smaller flue collar outlet.

2427.10.3.5 Size increase. Where the size of a vent connector is increased to overcome installation limitations and obtain connector capacity equal to the appliance input, the size increase shall be made at the appliance draft hood outlet.

2427.10.4 Two or more appliances connected to a single vent or chimney.

Where two or more vent connectors enter a common gas vent, chimney flue, or single-wall metal pipe, the smaller connector shall enter at the highest level consistent with the available headroom or clearance to combustible material. Vent connectors serving Category I appliances shall not be connected to any portion of a mechanical draft system operating under positive static pressure, such as those serving Category III or IV appliances.

2427.10.4.1 Two or more openings. Where two or more openings are provided into one chimney flue or vent, the openings shall be at different levels, or the connectors shall be attached to the vertical portion of the chimney or vent at an angle of 45 degrees ( 0.79 rad) or less relative to the vertical.

2427.10.5 Clearance. Minimum clearances from vent connectors to combustible material shall be in accordance with Table 2427.10.5.

Exception: The clearance between a vent connector and combustible material shall be permitted to be reduced where the combustible material is protected as specified for vent connectors in Table 2409.2.

2427.10.6 Flow resistance. A vent connector shall be installed so as to avoid turns or other construction features that create excessive resistance to flow of vent gases.

TABLE 2427.10.5a

CLEARANCES FOR CONNECTORS

APPLIANCE MINIMUM DISTANCE FROM COMBUSTIBLE MATERIAL
Listed Type B gas vent material Listed Type L vent material Single-wall metal pipe Factory-built chimney sections
Listed appliances with draft hoods and appliances listed for use with Type B gas vents As listed As listed 6 inches As listed
Residential boilers and furnaces with listed gas conversion burner and with draft hood 6 inches 6 inches 9 inches As listed
Residential appliances listed for use with Type L vents Not permitted As listed 9 inches As listed
Listed gas-fired toilets Not permitted As listed As listed As listed
Unlisted residential appliances with draft hood Not permitted 6 inches 9 inches As listed
Residential and low-heat appliances other than above Not permitted 9 inches 18 inches As listed
Medium-heat appliances Not permitted Not permitted 36 inches As listed

For SI: 1 inch = 25.4 mm.

a. These clearances shall apply unless the manufacturer's installation instructions for a listed appliance or connector specify different clearances, in which case the listed clearances shall apply.

2427.10.7 Joints. Joints between sections of connector piping and connections to flue collars and draft hood outlets shall be fastened by one of the following methods:

1. Sheet metal screws.

2. Vent connectors of listed vent material assembled and connected to flue collars or draft hood outlets in accordance with the manufacturers' instructions.

3. Other approved means.

2427.10.8 Slope. A vent connector shall be installed without dips or sags and shall slope upward toward the vent or chimney at least 1/4 inch per foot (21 mm/m).

Exception: Vent connectors attached to a mechanical draft system installed in accordance with the appliance and draft system manufacturers' instructions.

2427.10.9 Length of vent connector. A vent connector shall be as short as practical and the appliance located as close as practical to the chimney or vent. The maximum horizontal length of a single-wall connector shall be 75 percent of the height of the chimney or vent except for engineered systems. The maximum horizontal length of a Type B double-wall connector shall be 100 percent of the height of the chimney or vent except for engineered systems.

2427.10.10 Support. A vent connector shall be supported for the design and weight of the material employed to maintain clearances and prevent physical damage and separation of joints.

2427.10.11 Chimney connection. Where entering a flue in a masonry or metal chimney, the vent connector shall be installed above the extreme bottom to avoid stoppage. Where a thimble or slip joint is used to facilitate removal of the connector, the connector shall be firmly attached to or inserted into the thimble or slip joint to prevent the connector from falling out. Means shall be employed to prevent the connector from entering so far as to restrict the space between its end and the opposite wall of the chimney flue (see Section 2425.9 ).

2427.10.12 Inspection. The entire length of a vent connector shall be provided with ready access for inspection, cleaning, and replacement.

2427.10.13 Fireplaces. A vent connector shall not be connected to a chimney flue serving a fireplace unless the fireplace flue opening is permanently sealed.

2427.10.14 Passage through ceilings, floors or walls. Single-wall metal pipe connectors shall not pass through any wall, floor or ceiling except as permitted by Section 2427.7.4.

2427.11 Vent connectors for Category II, III and IV appliances. Vent connectors for Category II, III and IV appliances shall be as specified for the venting systems in accordance with Section 2427.4.

2427.12 Draft hoods and draft controls. The installation of draft hoods and draft controls shall comply with Sections 2427.12.1 through 2427.12.7.

2427.12.1 Appliances requiring draft hoods. Vented appliances shall be installed with draft hoods.

Exception: Dual oven-type combination ranges; incinerators; direct-vent appliances; fan-assisted combustion system appliances; appliances requiring chimney draft for operation; single firebox boilers equipped with conversion burners with inputs greater than 400,000 Btu per hour (117 kW); appliances equipped with blast, power or pressure burners that are not listed for use with draft hoods; and appliances designed for forced venting.

2427.12.2 Installation. A draft hood supplied with or forming a part of a listed vented appliance shall be installed without alteration, exactly as furnished and specified by the appliance manufacturer.

2427.12.2.1 Draft hood required. If a draft hood is not supplied by the appliance manufacturer where one is required, a draft hood shall be installed, shall be of a listed or approved type and, in the absence of other instructions, shall be of the same size as the appliance flue collar. Where a draft hood is required with a conversion burner, it shall be of a listed or approved type.

2427.12.2.2 Special design draft hood. Where it is determined that a draft hood of special design is needed or preferable for a particular installation, the installation shall be in accordance with the recommendations of the appliance manufacturer and shall be approved.

2427.12.3 Draft control devices. Where a draft control device is part of the appliance or is supplied by the appliance manufacturer, it shall be installed in accordance with the manufacturer's instructions. In the absence of manufacturer's instructions, the device shall be attached to the flue collar of the appliance or as near to the appliance as practical.

2427.12.4 Additional devices. Appliances (except incinerators) requiring a controlled chimney draft shall be permitted to be equipped with a listed double-acting barometric-draft regulator installed and adjusted in accordance with the manufacturer's instructions.

2427.12.5 Location. Draft hoods and barometric draft regulators shall be installed in the same room or enclosure as the appliance in such a manner as to prevent any difference in pressure between the hood or regulator and the combustion air supply.

2427.12.6 Positioning. Draft hoods and draft regulators shall be installed in the position for which they were designed with reference to the horizontal and vertical planes and shall be located so that the relief opening is not obstructed by any part of the appliance or adjacent construction. The appliance and its draft hood shall be located so that the relief opening is accessible for checking vent operation.

2427.12.7 Clearance. A draft hood shall be located so its relief opening is not less than 6 inches (152 mm) from any surface except that of the appliance it serves and the venting system to which the draft hood is connected. Where a greater or lesser clearance is indicated on the appliance label, the clearance shall be not less than that specified on the label. Such clearances shall not be reduced.

2427.13 Manually operated dampers. A manually operated damper shall not be placed in the vent connector for any appliance. Fixed baffles shall not be classified as manually operated dampers.

2427.14 Automatically operated vent dampers. An automatically operated vent damper shall be of a listed type.

2427.15 Obstructions. Devices that retard the flow of vent gases shall not be installed in a vent connector, chimney, or vent. The following shall not be considered as obstructions:

1. Draft regulators and safety controls specifically listed for installation in venting systems and installed in accordance with the manufacturer's installation instructions.

2. Approved draft regulators and safety controls that are designed and installed in accordance with approved engineering methods.

3. Listed heat reclaimers and automatically operated vent dampers installed in accordance with the manufacturer's installation instructions.

4. Approved economizers, heat reclaimers, and recuperators installed in venting systems of appliances not required to be equipped with draft hoods, provided that the appliance manufacturer's instructions cover the installation of such a device in the venting system and performance in accordance with Sections 2427.3 and 2427.3.1 is obtained.

5. Vent dampers serving listed appliances installed in accordance with Sections 2428.2.1 and 2428.3.1 or other approved engineering methods.

2427.16(IFGS) Outside wall penetrations. Where vents, including those for direct-vent appliances, penetrate outside walls of buildings, the annular spaces around such penetrations shall be permanently sealed using approved materials to prevent entry of combustion products into the building.

SECTION 2428

SIZING OF CATEGORY I APPLIANCE VENTING SYSTEMS

2428.1 Definitions. The following definitions apply to tables in this section.

APPLIANCE CATEGORIZED VENT DIAMETER/AREA. The minimum vent area/diameter permissible for Category I appliances to maintain a nonpositive vent static pressure when tested in accordance with nationally recognized standards.

FAN-ASSISTED COMBUSTION SYSTEM. An appliance equipped with an integral mechanical means to either draw or force products of combustion through the combustion chamber or heat exchanger.

FAN MIN. The minimum input rating of a Category I fan-assisted appliance attached to a vent or connector.

FAN MAX. The maximum input rating of a Category I fan-assisted appliance attached to a vent or connector.

NAT MAX. The maximum input rating of a Category I draft-hood-equipped appliance attached to a vent or connector.

FAN + FAN. The maximum combined appliance input rating of two or more Category I fan-assisted appliances attached to the common vent.

FAN + NAT. The maximum combined appliance input rating of one or more Category I fan-assisted appliances and one or more Category I draft-hood-equipped appliances attached to the common vent.

NA. Vent configuration is not permitted due to potential for condensate formation or pressurization of the venting system, or not applicable due to physical or geometric restraints.

NAT + NAT. The maximum combined appliance input rating of two or more Category I draft-hood-equipped appliances attached to the common vent.

2428.2 Application of single appliance vent Tables 2428.2(1) and 2428.2(2).

The application of Tables 2428.2(1) and 2428.2(2) shall be subject to the requirements of Sections 2428.2.1 through 2428.2.16.

2428.2.1 Vent obstructions. These venting tables shall not be used where obstructions, as described in Section 2427.15, are installed in the venting system. The installation of vents serving listed appliances with vent dampers shall be in accordance with the appliance manufacturer's instructions or in accordance with the following:

1. The maximum capacity of the vent system shall be determined using the "NAT Max" column.

2. The minimum capacity shall be determined as if the appliance were a fan-assisted appliance, using the "FAN Min" column to determine the minimum capacity of the vent system. Where the corresponding "FAN Min" is "NA," the vent configuration shall not be permitted and an alternative venting configuration shall be utilized.

2428.2.2 Minimum size. Where the vent size determined from the tables is smaller than the appliance draft hood outlet or flue collar, the smaller size shall be permitted to be used provided all of the following are met:

1. The total vent height (H) is at least 10 feet (3048 mm).

2. Vents for appliance draft hood outlets or flue collars 12 inches (305 mm) in diameter or smaller are not reduced more than one table size.

3. Vents for appliance draft hood outlets or flue collars larger than 12 inches (305 mm) in diameter are not reduced more than two table sizes.

4. The maximum capacity listed in the tables for a fan-assisted appliance is reduced by 10 percent ( 0.90 by maximum table capacity).

5. The draft hood outlet is greater than 4 inches (102 mm) in diameter. Do not connect a 3-inch-diameter (76 mm) vent to a 4-inch-diameter (102 mm) draft hood outlet. This provision shall not apply to fan-assisted appliances.

TABLE 2428.2(1)

TYPE B DOUBLE-WALL GAS VENT

Number of Appliances Single
Appliance Type Category I
Appliance Vent Connection Connected directly to vent

HEI GHT (H)(feet) LAT ERAL (L)(f eet) VENT DIAMETER-(D) inches
3 4 5 6 7 8 9
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT
Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max
6 0 0 78 46 0 152 86 0 251 141 0 375 205 0 524 285 0 698 370 0 897 470
2 13 51 36 18 97 67 27 157 105 32 232 157 44 321 217 53 425 285 63 543 370
4 21 49 34 30 94 64 39 153 103 50 227 153 66 316 211 79 419 279 93 536 362
6 25 46 32 36 91 61 47 149 100 59 223 149 78 310 205 93 413 273 110 530 354
8 0 0 84 50 0 165 94 0 276 155 0 415 235 0 583 320 0 780 415 0 1,006 537
2 12 57 40 16 109 75 25 178 120 28 263 180 42 365 247 50 483 322 60 619 418
5 23 53 38 32 103 71 42 171 115 53 255 173 70 356 237 83 473 313 99 607 407
8 28 49 35 39 98 66 51 164 109 64 247 165 84 347 227 99 463 303 117 596 396
10 0 0 88 53 0 175 100 0 295 166 0 447 255 0 631 345 0 847 450 0 1,096 585
2 12 61 42 17 118 81 23 194 129 26 289 195 40 402 273 48 533 355 57 684 457
5 23 57 40 32 113 77 41 187 124 52 280 188 68 392 263 81 522 346 95 671 446
10 30 51 36 41 104 70 54 176 115 67 267 175 88 376 245 104 504 330 122 651 427
15 0 0 94 58 0 191 112 0 327 187 0 502 285 0 716 390 0 970 525 0 1,263 682
2 11 69 48 15 136 93 20 226 150 22 339 225 38 475 316 45 633 414 53 815 544
5 22 65 45 30 130 87 39 219 142 49 330 217 64 463 300 76 620 403 90 800 529
10 29 59 41 40 121 82 51 206 135 64 315 208 84 445 288 99 600 386 116 777 507
15 35 53 37 48 112 76 61 195 128 76 301 198 98 429 275 115 580 373 134 755 491
20 0 0 97 61 0 202 119 0 349 202 0 540 307 0 776 430 0 1,057 575 0 1,384 752
2 10 75 51 14 149 100 18 250 166 20 377 249 33 531 346 41 711 470 50 917 612
5 21 71 48 29 143 96 38 242 160 47 367 241 62 519 337 73 697 460 86 902 599
10 28 64 44 38 133 89 50 229 150 62 351 228 81 499 321 95 675 443 112 877 576
15 34 58 40 46 124 84 59 217 142 73 337 217 94 481 308 111 654 427 129 853 557
20 48 52 35 55 116 78 69 206 134 84 322 206 107 464 295 125 634 410 145 830 537
30 0 0 100 64 0 213 128 0 374 220 0 587 336 0 853 475 0 1,173 650 0 1,548 855
2 9 81 56 13 166 112 14 283 185 18 432 280 27 613 394 33 826 535 42 1,072 700
5 21 77 54 28 160 108 36 275 176 45 421 273 58 600 385 69 811 524 82 1,055 688
10 27 70 50 37 150 102 48 262 171 59 405 261 77 580 371 91 788 507 107 1,028 668
15 33 64 NA 44 141 96 57 249 163 70 389 249 90 560 357 105 765 490 124 1,002 648
20 56 58 NA 53 132 90 66 237 154 80 374 237 102 542 343 119 743 473 139 977 628
30 NA NA NA 73 113 NA 88 214 NA 104 346 219 131 507 321 149 702 444 171 929 594
50 0 0 101 67 0 216 134 0 397 232 0 633 363 0 932 518 0 1,297 708 0 1,730 952
2 8 86 61 11 183 122 14 320 206 15 497 314 22 715 445 26 975 615 33 1,276 813
5 20 82 NA 27 177 119 35 312 200 43 487 308 55 702 438 65 960 605 77 1,259 798
10 26 76 NA 35 168 114 45 299 190 56 471 298 73 681 426 86 935 589 101 1,230 773
15 59 70 NA 42 158 NA 54 287 180 66 455 288 85 662 413 100 911 572 117 1,203 747
20 NA NA NA 50 149 NA 63 275 169 76 440 278 97 642 401 113 888 556 131 1,176 722
30 NA NA NA 69 131 NA 84 250 NA 99 410 259 123 605 376 141 844 522 161 1,125 670

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W.

TABLE 2428.2(2)

TYPE B DOUBLE-WALL GAS VENT

Number of Appliances Single
Appliance Type Category I
Appliance Vent Connection Single-wall metal connector

HEI GHT (H) (feet) LAT ERA L(L) (feet) VENT DIAMETER-(D) inches
3 4 5 6 7 8 9 10 12
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT
Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max
6 0 38 77 45 59 151 85 85 249 140 126 373 204 165 522 284 211 695 369 267 894 469 371 1,118 569 537 1,639 849
2 39 51 36 60 96 66 85 156 104 123 231 156 159 320 213 201 423 284 251 541 368 347 673 453 498 979 648
4 NA NA 33 74 92 63 102 152 102 146 225 152 187 313 208 237 416 277 295 533 360 409 664 443 584 971 638
6 NA NA 31 83 89 60 114 147 99 163 220 148 207 307 203 263 409 271 327 526 352 449 656 433 638 962 627
8 0 37 83 50 58 164 93 83 273 154 123 412 234 161 580 319 206 777 414 258 1,002 536 360 1,257 658 521 1,852 967
2 39 56 39 59 108 75 83 176 119 121 261 179 155 363 246 197 482 321 246 617 417 339 768 513 486 1,120 743
5 NA NA 37 77 102 69 107 168 114 151 252 171 193 352 235 245 470 311 305 604 404 418 754 500 598 1,104 730
8 NA NA 33 90 95 64 122 161 107 175 243 163 223 342 225 280 458 300 344 591 392 470 740 486 665 1,089 715
10 0 37 87 53 57 174 99 82 293 165 120 444 254 158 628 344 202 844 449 253 1,093 584 351 1,373 718 507 2,031 1,057
2 39 61 41 59 117 80 82 193 128 119 287 194 153 400 272 193 531 354 242 681 456 332 849 559 475 1,242 848
5 52 56 39 76 111 76 105 185 122 148 277 186 190 388 261 241 518 344 299 667 443 409 834 544 584 1,224 825
10 NA NA 34 97 100 68 132 171 112 188 261 171 237 369 241 296 497 325 363 643 423 492 808 520 688 1,194 788
15 0 36 93 57 56 190 111 80 325 186 116 499 283 153 713 388 195 966 523 244 1,259 681 336 1,591 838 488 2,374 1,237
2 38 69 47 57 136 93 80 225 149 115 337 224 148 473 314 187 631 413 232 812 543 319 1,015 673 457 1,491 983
5 51 63 44 75 128 86 102 216 140 144 326 217 182 459 298 231 616 400 287 795 526 392 997 657 562 1,469 963
10 NA NA 39 95 116 79 128 201 131 182 308 203 228 438 284 284 592 381 349 768 501 470 966 628 664 1,433 928
15 NA NA NA NA NA 72 158 186 124 220 290 192 272 418 269 334 568 367 404 742 484 540 937 601 750 1,399 894
20 0 35 96 60 54 200 118 78 346 201 114 537 306 149 772 428 190 1,053 573 238 1,379 750 326 1,751 927 473 2,631 1,346
2 37 74 50 56 148 99 78 248 165 113 375 248 144 528 344 182 708 468 227 914 611 309 1,146 754 443 1,689 1,098
5 50 68 47 73 140 94 100 239 158 141 363 239 178 514 334 224 692 457 279 896 596 381 1,126 734 547 1,665 1,074
10 NA NA 41 93 129 86 125 223 146 177 344 224 222 491 316 277 666 437 339 866 570 457 1,092 702 646 1,626 1,037
15 NA NA NA NA NA 80 155 208 136 216 325 210 264 469 301 325 640 419 393 838 549 526 1,060 677 730 1,587 1,005
20 NA NA NA NA NA NA 186 192 126 254 306 196 309 448 285 374 616 400 448 810 526 592 1,028 651 808 1,550 973
30 0 34 99 63 53 211 127 76 372 219 110 584 334 144 849 472 184 1,168 647 229 1,542 852 312 1,971 1,056 454 2,996 1,545
2 37 80 56 55 164 111 76 281 183 109 429 279 139 610 392 175 823 533 219 1,069 698 296 1,346 863 424 1,999 1,308
5 49 74 52 72 157 106 98 271 173 136 417 271 171 595 382 215 806 521 269 1,049 684 366 1,324 846 524 1,971 1,283
10 NA NA NA 91 144 98 122 255 168 171 397 257 213 570 367 265 777 501 327 1,017 662 440 1,287 821 620 1,927 1,234
15 NA NA NA 115 131 NA 151 239 157 208 377 242 255 547 349 312 750 481 379 985 638 507 1,251 794 702 1,884 1,205
20 NA NA NA NA NA NA 181 223 NA 246 357 228 298 524 333 360 723 461 433 955 615 570 1,216 768 780 1,841 1,166
30 NA NA NA NA NA NA NA NA NA NA NA NA 389 477 305 461 670 426 541 895 574 704 1,147 720 937 1,759 1,101
50 0 33 99 66 51 213 133 73 394 230 105 629 361 138 928 515 176 1,292 704 220 1,724 948 295 2,223 1,189 428 3,432 1,818
2 36 84 61 53 181 121 73 318 205 104 495 312 133 712 443 168 971 613 209 1,273 811 280 1,615 1,007 401 2,426 1,509
5 48 80 NA 70 174 117 94 308 198 131 482 305 164 696 435 204 953 602 257 1,252 795 347 1,591 991 496 2,396 1,490
10 NA NA NA 89 160 NA 118 292 186 162 461 292 203 671 420 253 923 583 313 1,217 765 418 1,551 963 589 2,347 1,455
15 NA NA NA 112 148 NA 145 275 174 199 441 280 244 646 405 299 894 562 363 1,183 736 481 1,512 934 668 2,299 1,421
20 NA NA NA NA NA NA 176 257 NA 236 420 267 285 622 389 345 866 543 415 1,150 708 544 1,473 906 741 2,251 1,387
30 NA NA NA NA NA NA NA NA NA 315 376 NA 373 573 NA 442 809 502 521 1,086 649 674 1,399 848 892 2,159 1,318

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W.

2428.2.3 Vent offsets. Single-appliance venting configurations with zero (0) lateral lengths in Tables 2428.2(1) and 2428.2(2) shall not have elbows in the venting system. Single-appliance venting configurations with lateral lengths include two 90-degree ( 1.57 rad) elbows. For each additional elbow up to and including 45 degrees ( 0.79 rad), the maximum capacity listed in the venting tables shall be reduced by 5 percent. For each additional elbow greater than 45 degrees ( 0.79 rad) up to and including 90 degrees ( 1.57 rad), the maximum capacity listed in the venting tables shall be reduced by 10 percent. Where multiple offsets occur in a vent, the total lateral length of all offsets combined shall not exceed that specified in Tables 2428.2(1) and 2428.2(2).

2428.2.4 Zero lateral. Zero (0) lateral (L) shall apply only to a straight vertical vent attached to a top outlet draft hood or flue collar.

2428.2.5 High altitude installations. Sea level input ratings shall be used when determining maximum capacity for high altitude installation. Actual input, derated for altitude, shall be used for determining minimum capacity for high altitude installation.

2428.2.6 Multiple input rate appliances. For appliances with more than one input rate, the minimum vent capacity (FAN Min) determined from the tables shall be less than the lowest appliance input rating, and the maximum vent capacity (FAN Max/NAT Max) determined from the tables shall be greater than the highest appliance rating input.

2428.2.7 Liner system sizing and connections. Listed corrugated metallic chimney liner systems in masonry chimneys shall be sized by using Table 2428.2(1) or 2428.2(2) for Type B vents with the maximum capacity reduced by 20 percent ( 0.80 x maximum capacity) and the minimum capacity as shown in Table 2428.2(1) or 2428.2(2). Corrugated metallic liner systems installed with bends or offsets shall have their maximum capacity further reduced in accordance with Section 2428.2.3. The 20-percent reduction for corrugated metallic chimney liner systems includes an allowance for one long-radius 90-degree ( 1.57 rad) turn at the bottom of the liner.

Connections between chimney liners and listed double-wall connectors shall be made with listed adapters designed for such purpose.

2428.2.8 Vent area and diameter. Where the vertical vent has a larger diameter than the vent connector, the vertical vent diameter shall be used to determine the minimum vent capacity, and the connector diameter shall be used to determine the maximum vent capacity. The flow area of the vertical vent shall not exceed seven times the flow area of the listed appliance categorized vent area, flue collar area, or draft hood outlet area unless designed in accordance with approved engineering methods.

2428.2.9 Chimney and vent locations. Tables 2428.2(1) and 2428.2(2) shall be used only for chimneys and vents not exposed to the outdoors below the roof line. A Type B vent or listed chimney lining system passing through an unused masonry chimney flue shall not be considered to be exposed to the outdoors. A Type B vent shall not be considered to be exposed to the outdoors where it passes through an unventilated enclosure or chase insulated to a value of not less than R-8.

2428.2.10 Corrugated vent connector size. Corrugated vent connectors shall be not smaller than the listed appliance categorized vent diameter, flue collar diameter, or draft hood outlet diameter.

2428.2.11 Vent connector size limitation. Vent connectors shall not be increased in size more than two sizes greater than the listed appliance categorized vent diameter, flue collar diameter or draft hood outlet diameter.

2428.2.12 Component commingling. In a single run of vent or vent connector, different diameters and types of vent and connector components shall be permitted to be used, provided that all such sizes and types are permitted by the tables.

2428.2.13 Draft hood conversion accessories. Draft hood conversion accessories for use with masonry chimneys venting listed Category I fan-assisted appliances shall be listed and installed in accordance with the manufacturer's installation instructions for such listed accessories.

2428.2.14 Table interpolation. Interpolation shall be permitted in calculating capacities for vent dimensions that fall between the table entries (see Example 3, Appendix B).

2428.2.15 Extrapolation prohibited. Extrapolation beyond the table entries shall not be permitted.

2428.2.16 Engineering calculations. For vent heights less than 6 feet (1829 mm) and greater than shown in the tables, engineering methods shall be used to calculate vent capacities.

2428.3 Application of multiple appliance vent Tables 2428.3(1) through 2428.3(4). The application of Tables 2428.3(1) through 2428.3(4) shall be subject to the requirements of Sections 2428.3.1 through 2428.3.23.

TABLE 2428.3(1)

TYPE B DOUBLE-WALL VENT

Number of Appliances Two or more
Appliance Type Category I
Appliance Vent Connection Type B double-wall connector

VENT CONNECTOR CAPACITY

HEI GHT (H)(feet) LAT ERAL (L)(f eet) TYPE B DOUBLE-WALL VENT AND CONNECTOR DIAMETER-(D) inches
3 4 5 6 7 8 9 10
APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT
Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max
6
1 22 37 26 35 66 46 46 106 72 58 164 104 77 225 142 92 296 185 109 376 237 128 466 289
2 23 41 31 37 75 55 48 121 86 60 183 124 79 253 168 95 333 220 112 424 282 131 526 345
3 24 44 35 38 81 62 49 132 96 62 199 139 82 275 189 97 363 248 114 463 317 134 575 386
8 1 22 40 27 35 72 48 49 114 76 64 176 109 84 243 148 100 320 194 118 408 248 138 507 303
2 23 44 32 36 80 57 51 128 90 66 195 129 86 269 175 103 356 230 121 454 294 141 564 358
3 24 47 36 37 87 64 53 139 101 67 210 145 88 290 198 105 384 258 123 492 330 143 612 402
10 1 22 43 28 34 78 50 49 123 78 65 189 113 89 257 154 106 341 200 125 436 257 146 542 314
2 23 47 33 36 86 59 51 136 93 67 206 134 91 282 182 109 374 238 128 479 305 149 596 372
3 24 50 37 37 92 67 52 146 104 69 220 150 94 303 205 111 402 268 131 515 342 152 642 417
15 1 21 50 30 33 89 53 47 142 83 64 220 120 88 298 163 110 389 214 134 493 273 162 609 333
2 22 53 35 35 96 63 49 153 99 66 235 142 91 320 193 112 419 253 137 532 323 165 658 394
3 24 55 40 36 102 71 51 163 111 68 248 160 93 339 218 115 445 286 140 565 365 167 700 444
20 1 21 54 31 33 99 56 46 157 87 62 246 125 86 334 171 107 436 224 131 552 285 158 681 347
2 22 57 37 34 105 66 48 167 104 64 259 149 89 354 202 110 463 265 134 587 339 161 725 414
3 23 60 42 35 110 74 50 176 116 66 271 168 91 371 228 113 486 300 137 618 383 164 764 466
30 1 20 62 33 31 113 59 45 181 93 60 288 134 83 391 182 103 512 238 125 649 305 151 802 372
2 21 64 39 33 118 70 47 190 110 62 299 158 85 408 215 105 535 282 129 679 360 155 840 439
3 22 66 44 34 123 79 48 198 124 64 309 178 88 423 242 108 555 317 132 706 405 158 874 494

COMMON VENT CAPACITY

VENT HEIGHT (H) (feet) TYPE B DOUBLE-WALL COMMON VENT DIAMETER (D)-inches
4 5 6 7 8 9 10
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT
6 92 81 65 140 116 103 204 161 147 309 248 200 404 314 260 547 434 335 672 520 410
8 101 90 73 155 129 114 224 178 163 339 275 223 444 348 290 602 480 378 740 577 465
10 110 97 79 169 141 124 243 194 178 367 299 242 477 377 315 649 522 405 800 627 495
15 125 112 91 195 164 144 283 228 206 427 352 280 556 444 365 753 612 465 924 733 565
20 136 123 102 215 183 160 314 255 229 475 394 310 621 499 405 842 688 523 1,035 826 640
30 152 138 118 244 210 185 361 297 266 547 459 360 720 585 470 979 808 605 1,209 975 740
50 167 153 134 279 244 214 421 353 310 641 547 423 854 706 550 1,164 977 705 1,451 1,188 860

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W.

TABLE 2428.3(2)

TYPE B DOUBLE-WALL VENT

Number of Appliances Two or more
Appliance Type Category I
Appliance Vent Connection Single-wall metal connector

VENT CONNECTOR CAPACITY

VENT HEIGHT (H) (feet) CONNECTOR RISE (R) (feet) SINGLE-WALL METAL VENT CONNECTOR DIAMETER-(D) inches
3 4 5 6 7 8 9 10
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU/H
FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT
Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max
6 1 NA NA 26 NA NA 46 NA NA 71 NA NA 102 207 223 140 262 293 183 325 373 234 447 463 286
2 NA NA 31 NA NA 55 NA NA 85 168 182 123 215 251 167 271 331 219 334 422 281 458 524 344
3 NA NA 34 NA NA 62 121 131 95 175 198 138 222 273 188 279 361 247 344 462 316 468 574 385
8 1 NA NA 27 NA NA 48 NA NA 75 NA NA 106 226 240 145 285 316 191 352 403 244 481 502 299
2 NA NA 32 NA NA 57 125 126 89 184 193 127 234 266 173 293 353 228 360 450 292 492 560 355
3 NA NA 35 NA NA 64 130 138 100 191 208 144 241 287 197 302 381 256 370 489 328 501 609 400
10 1 NA NA 28 NA NA 50 119 121 77 182 186 110 240 253 150 302 335 196 372 429 252 506 534 308
2 NA NA 33 84 85 59 124 134 91 189 203 132 248 278 183 311 369 235 381 473 302 517 589 368
3 NA NA 36 89 91 67 129 144 102 197 217 148 257 299 203 320 398 265 391 511 339 528 637 413
15 1 NA NA 29 79 87 52 116 138 81 177 214 116 238 291 158 312 380 208 397 482 266 556 596 324
2 NA NA 34 83 94 62 121 150 97 185 230 138 246 314 189 321 411 248 407 522 317 568 646 387
3 NA NA 39 87 100 70 127 160 109 193 243 157 255 333 215 331 438 281 418 557 360 579 690 437
20 1 49 56 30 78 97 54 115 152 84 175 238 120 233 325 165 306 425 217 390 538 276 546 664 336
2 52 59 36 82 103 64 120 163 101 182 252 144 243 346 197 317 453 259 400 574 331 558 709 403
3 55 62 40 87 107 72 125 172 113 190 264 164 252 363 223 326 476 294 412 607 375 570 750 457
30 1 47 60 31 77 110 57 112 175 89 169 278 129 226 380 175 296 497 230 378 630 294 528 779 358
2 51 62 37 81 115 67 117 185 106 177 290 152 236 397 208 307 512 274 389 662 349 541 819 425
3 54 64 42 85 119 76 122 193 120 185 300 172 244 412 235 316 542 309 400 690 394 555 855 482

COMMON VENT CAPACITY

VENT HEIGHT (H) (feet) TYPE B DOUBLE-WALL COMMON VENT DIAMETER- (D) inches
4 5 6 7 8 9 10
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN FAN +FAN
6 NA 78 64 NA 113 99 200 158 144 304 244 196 398 310 257 541 429 332 665 515 407
8 NA 87 71 NA 126 111 218 173 159 331 269 218 436 342 285 592 473 373 730 569 460
10 NA 94 76 163 137 120 237 189 174 357 292 236 467 369 309 638 512 398 787 617 487
15 121 108 88 189 159 140 275 221 200 416 343 274 544 434 357 738 599 456 905 718 553
20 131 118 98 208 177 156 305 247 223 463 383 302 606 487 395 824 673 512 1,013 808 626
30 145 132 113 236 202 180 350 286 257 533 446 349 703 570 459 958 790 593 1,183 952 723
50 159 145 128 268 233 208 406 337 296 622 529 410 833 686 535 1,139 954 689 1,418 1,157 838

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W.

TABLE 2428.3(3)

MASONRY CHIMNEY

Number of Appliances Two or more
Appliance Type Category I
Appliance Vent Connection Type B double-wall connector

VENT CONNECTOR CAPACITY

VENT HEIGHT (H) (feet) CONNECTOR RISE (R) (feet) TYPE B DOUBLE-WALL VENT CONNECTOR DIAMETER-(D) inches
3 4 5 6 7 8 9 10
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU/H
FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT
Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max
6 1 24 33 21 39 62 40 52 106 67 65 194 101 87 274 141 104 370 201 124 479 253 145 599 319
2 26 43 28 41 79 52 53 133 85 67 230 124 89 324 173 107 436 232 127 562 300 148 694 378
3 27 49 34 42 92 61 55 155 97 69 262 143 91 369 203 109 491 270 129 633 349 151 795 439
8 1 24 39 22 39 72 41 55 117 69 71 213 105 94 304 148 113 414 210 134 539 267 156 682 335
2 26 47 29 40 87 53 57 140 86 73 246 127 97 350 179 116 473 240 137 615 311 160 776 394
3 27 52 34 42 97 62 59 159 98 75 269 145 99 383 206 119 517 276 139 672 358 163 848 452
10 1 24 42 22 38 80 42 55 130 71 74 232 108 101 324 153 120 444 216 142 582 277 165 739 348
2 26 50 29 40 93 54 57 153 87 76 261 129 103 366 184 123 498 247 145 652 321 168 825 407
3 27 55 35 41 105 63 58 170 100 78 284 148 106 397 209 126 540 281 147 705 366 171 893 463
15 1 24 48 23 38 93 44 54 154 74 72 277 114 100 384 164 125 511 229 153 658 297 184 824 375
2 25 55 31 39 105 55 56 174 89 74 299 134 103 419 192 128 558 260 156 718 339 187 900 432
3 26 59 35 41 115 64 57 189 102 76 319 153 105 448 215 131 597 292 159 760 382 190 960 486
20 1 24 52 24 37 102 46 53 172 77 71 313 119 98 437 173 123 584 239 150 752 312 180 943 397
2 25 58 31 39 114 56 55 190 91 73 335 138 101 467 199 126 625 270 153 805 354 184 1,011 452
3 26 63 35 40 123 65 57 204 104 75 353 157 104 493 222 129 661 301 156 851 396 187 1,067 505

COMMON VENT CAPACITY

VENT HEIGHT (H) (feet) MINIMUM INTERNAL AREA OF MASONRY CHIMNEY FLUE (square inches)
12 19 78 28 38 50 63 113
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT
6 NA 74 25 NA 119 46 NA 178 71 NA 257 103 NA 351 143 NA 458 188 NA 582 246 1,041 853 NA
8 NA 80 28 NA 130 53 NA 193 82 NA 279 119 NA 384 163 NA 501 218 724 636 278 1,144 937 408
10 NA 84 31 NA 138 56 NA 207 90 NA 299 131 NA 409 177 606 538 236 776 686 302 1,226 1,010 454
15 NA NA 36 NA 152 67 NA 233 106 NA 334 152 523 467 212 682 611 283 874 781 365 1,374 1,156 546
20 NA NA 41 NA NA 75 NA 250 122 NA 368 172 565 508 243 742 668 325 955 858 419 1,513 1,286 648
30 NA NA NA NA NA NA NA 270 137 NA 404 198 615 564 278 816 747 381 1,062 969 496 1,702 1,473 749
50 NA NA NA NA NA NA NA NA NA NA NA NA NA 620 328 879 831 461 1,165 1,089 606 1,905 1,692 922

For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm2, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W.

TABLE 2428.3(4)

MASONRY CHIMNEY

Number of Appliances Two or more
Appliance Type Category I
Appliance Vent Connection Single-wall metal connector

VENT CONNECTOR CAPACITY

VENT HEIGHT (H) (feet) CONNECTOR RISE (R) (feet) SINGLE-WALL METAL VENT CONNECTOR DIAMETER (D)-inches
3 4 5 6 7 8 9 10
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU/H
FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT FAN NAT
Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max Min Max Max
6 1 NA NA 21 NA NA 39 NA NA 66 179 191 100 231 271 140 292 366 200 362 474 252 499 594 316
2 NA NA 28 NA NA 52 NA NA 84 186 227 123 239 321 172 301 432 231 373 557 299 509 696 376
3 NA NA 34 NA NA 61 134 153 97 193 258 142 247 365 202 309 491 269 381 634 348 519 793 437
8 1 NA NA 21 NA NA 40 NA NA 68 195 208 103 250 298 146 313 407 207 387 530 263 529 672 331
2 NA NA 28 NA NA 52 137 139 85 202 240 125 258 343 177 323 465 238 397 607 309 540 766 391
3 NA NA 34 NA NA 62 143 156 98 210 264 145 266 376 205 332 509 274 407 663 356 551 838 450
10 1 NA NA 22 NA NA 41 130 151 70 202 225 106 267 316 151 333 434 213 410 571 273 558 727 343
2 NA NA 29 NA NA 53 136 150 86 210 255 128 276 358 181 343 489 244 420 640 317 569 813 403
3 NA NA 34 97 102 62 143 166 99 217 277 147 284 389 207 352 530 279 430 694 363 580 880 459
15 1 NA NA 23 NA NA 43 129 151 73 199 271 112 268 376 161 349 502 225 445 646 291 623 808 366
2 NA NA 30 92 103 54 135 170 88 207 295 132 277 411 189 359 548 256 456 706 334 634 884 424
3 NA NA 34 96 112 63 141 185 101 215 315 151 286 439 213 368 586 289 466 755 378 646 945 479
20 1 NA NA 23 87 99 45 128 167 76 197 303 117 265 425 169 345 569 235 439 734 306 614 921 347
2 NA NA 30 91 111 55 134 185 90 205 325 136 274 455 195 355 610 266 450 787 348 627 986 443
3 NA NA 35 96 119 64 140 199 103 213 343 154 282 481 219 365 644 298 461 831 391 639 1,042 496

COMMON VENT CAPACITY

VENT HEIGHT (H) (feet) MINIMUM INTERNAL AREA OF MASONRY CHIMNEY FLUE (square inches)
12 19 28 38 50 63 78 113
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU/H
FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT FAN +FAN FAN +NAT NAT +NAT
6 NA NA 25 NA 118 45 NA 176 71 NA 255 102 NA 348 142 NA 455 187 NA 579 245 NA 846 NA
8 NA NA 28 NA 128 52 NA 190 81 NA 276 118 NA 380 162 NA 497 217 NA 633 277 1,136 928 405
10 NA NA 31 NA 136 56 NA 205 89 NA 295 129 NA 405 175 NA 532 234 171 680 300 1,216 1,000 450
15 NA NA 36 NA NA 66 NA 230 105 NA 335 150 NA 400 210 677 602 280 866 772 360 1,359 1,139 540
20 NA NA NA NA NA 74 NA 247 120 NA 362 170 NA 503 240 765 661 321 947 849 415 1,495 1,264 640
30 NA NA NA NA NA NA NA NA 135 NA 398 195 NA 558 275 808 739 377 1,052 957 490 1,682 1,447 740
50 NA NA NA NA NA NA NA NA NA NA NA NA NA 612 325 NA 821 456 1,152 1,076 600 1,879 1,672 910

For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm2, 1 foot = 304.8 mm, 1 British thermal unit per hour = 0.2931 W.

2428.3.1 Vent obstructions. These venting tables shall not be used where obstructions, as described in Section 2427.15, are installed in the venting system. The installation of vents serving listed appliances with vent dampers shall be in accordance with the appliance manufacturer's instructions or in accordance with the following:

1. The maximum capacity of the vent connector shall be determined using the NAT Max column.

2. The maximum capacity of the vertical vent or chimney shall be determined using the FAN+NAT column when the second appliance is a fan-assisted appliance, or the NAT+NAT column when the second appliance is equipped with a draft hood.

3. The minimum capacity shall be determined as if the appliance were a fan-assisted appliance.

3.

1. The minimum capacity of the vent connector shall be determined using the FAN Min column.

3.

2. The FAN+FAN column shall be used when the second appliance is a fan-assisted appliance, and the FAN+NAT column shall be used when the second appliance is equipped with a draft hood, to determine whether the vertical vent or chimney configuration is not permitted (NA). Where the vent configuration is NA, the vent configuration shall not be permitted and an alternative venting configuration shall be utilized.

2428.3.2 Connector length limit. The vent connector shall be routed to the vent utilizing the shortest possible route. Except as provided in Section 2428.3.3, the maximum vent connector horizontal length shall be 1.5 feet (457 mm) for each inch (18 mm per mm) of connector diameter as shown in Table 2428.3.2.

TABLE 2428.3.2

MAXIMUM VENT CONNECTOR LENGTH

CONNECTOR DIAMETER CONNECTOR HORIZONTAL
Maximum (inches) Length (feet)
3 4.5
4 6
5 7.5
6 9
7 10.5
8 12
9 13.5

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

2428.3.3 Connectors with longer lengths. Connectors with longer horizontal lengths than those listed in Section 2428.3.2 are permitted under the following conditions:

1. The maximum capacity (FAN Max or NAT Max) of the vent connector shall be reduced 10 percent for each additional multiple of the length listed above. For example, the maximum length listed above for a 4-inch (102 mm) connector is 6 feet (1829 mm). With a connector length greater than 6 feet (1829 mm), but not exceeding 12 feet (3658 mm), the maximum capacity must be reduced by 10 percent ( 0.90 * maximum vent connector capacity). With a connector length greater than 12 feet (3658 mm), but not exceeding 18 feet (5486 mm), the maximum capacity must be reduced by 20 percent ( 0.80 x maximum vent capacity).

2. For a connector serving a fan-assisted appliance, the minimum capacity (FAN Min) of the connector shall be determined by referring to the corresponding single appliance table. For Type B double-wall connectors, Table 2428.2(1) shall be used. For single-wall connectors, Table 2428.2(2) shall be used. The height (H) and lateral (L) shall be measured according to the procedures for a single appliance vent, as if the other appliances were not present.

2428.3.4 Vent connector manifold. Where the vent connectors are combined prior to entering the vertical portion of the common vent to form a common vent manifold, the size of the common vent manifold and the common vent shall be determined by applying a 10-percent reduction ( 0.90 x maximum common vent capacity) to the common vent capacity part of the common vent tables. The length of the common vent connector manifold (LM) shall not exceed 11/2 feet for each inch (18 mm per mm) of common vent connector manifold diameter (D)

2428.3.5 Common vertical vent offset. Where the common vertical vent is offset, the maximum capacity of the common vent shall be reduced in accordance with Section 2428.3.6. The horizontal length of the common vent offset (Lo) shall not exceed 11/2 feet for each inch (18 mm per mm) of common vent diameter (D). Where multiple offsets occur in a common vent, the total horizontal length of all offsets combined shall not exceed 11/2 feet for each inch (18 mm/mm per) of the common vent diameter (D).

2428.3.6 Elbows in vents. For each elbow up to and including 45 degrees ( 0.79 rad) in the common vent, the maximum common vent capacity listed in the venting tables shall be reduced by 5 percent. For each elbow greater than 45 degrees ( 0.79 rad) up to and including 90 degrees ( 1.57 rad), the maximum common vent capacity listed in the venting tables shall be reduced by 10 percent.

2428.3.7 Elbows in connectors. The vent connector capacities listed in the common vent sizing tables include allowance for two 90-degree ( 1.57 rad) elbows. For each additional elbow up to and including 45 degrees ( 0.79 rad), the maximum vent connector capacity listed in the venting tables shall be reduced by 5 percent. For each elbow greater than 45 degrees ( 0.79 rad) up to and including 90 degrees ( 1.57 rad), the maximum vent connector capacity listed in the venting tables shall be reduced by 10 percent.

2428.3.8 Common vent minimum size. The cross-sectional area of the common vent shall be equal to or greater than the cross-sectional area of the largest connector.

2428.3.9 Common vent fittings. At the point where tee or wye fittings connect to a common vent, the opening size of the fitting shall be equal to the size of the common vent. Such fittings shall not be prohibited from having reduced-size openings at the point of connection of appliance vent connectors.

2428.3.9.1 Tee and wye fittings. Tee and wye fittings connected to a common gas vent shall be considered as part of the common gas vent and shall be constructed of materials consistent with that of the common gas vent.

2428.3.10 High altitude installations. Sea-level input ratings shall be used when determining maximum capacity for high altitude installation. Actual input, derated for altitude, shall be used for determining minimum capacity for high altitude installation.

2428.3.11 Connector rise measurement. Connector rise (R) for each appliance connector shall be measured from the draft hood outlet or flue collar to the centerline where the vent gas streams come together.

2428.3.12 Vent height measurement. For multiple appliances all located on one floor, available total height (H) shall be measured from the highest draft hood outlet or flue collar up to the level of the outlet of the common vent.

2428.3.13 Vertical vent maximum size. Where two or more appliances are connected to a vertical vent or chimney, the flow area of the largest section of vertical vent or chimney shall not exceed seven times the smallest listed appliance categorized vent areas, flue collar area, or draft hood outlet area unless designed in accordance with approved engineering methods.

2428.3.14 Multiple input rate appliances. For appliances with more than one input rate, the minimum vent connector capacity (FAN Min) determined from the tables shall be less than the lowest appliance input rating, and the maximum vent connector capacity (FAN Max or NAT Max) determined from the tables shall be greater than the highest appliance input rating.

2428.3.15 Liner system sizing and connections. Listed, corrugated metallic chimney liner systems in masonry chimneys shall be sized by using Table 2428.3(1) or 2428.3(2) for Type B vents, with the maximum capacity reduced by 20 percent ( 0.80 x maximum capacity) and the minimum capacity as shown in Table 2428.3(1) or 2428.3(2). Corrugated metallic liner systems installed with bends or offsets shall have their maximum capacity further reduced in accordance with Sections 2428.3.5 and 2428.3.6. The 20-percent reduction for corrugated metallic chimney liner systems includes an allowance for one long-radius 90-degree ( 1.57 rad) turn at the bottom of the liner. Where double-wall connectors are required, tee and wye fittings used to connect to the common vent chimney liner shall be listed double-wall fittings. Connections between chimney liners and listed double-wall fittings shall be made with listed adapter fittings designed for such purpose.

2428.3.16 Chimney and vent location. Tables 2428.3(1), 2428.3(2), 2428.3(3) and 2428.3(4) shall be used only for chimneys and vents not exposed to the outdoors below the roof line. A Type B vent or listed chimney lining system passing through an unused masonry chimney flue shall not be considered to be exposed to the outdoors. A Type B vent shall not be considered to be exposed to the outdoors where it passes through an unventilated enclosure or chase insulated to a value of not less than R-8.

2428.3.17 Connector maximum and minimum size. Vent connectors shall not be increased in size more than two sizes greater than the listed appliance categorized vent diameter, flue collar diameter, or draft hood outlet diameter. Vent connectors for draft-hood-equipped appliances shall not be smaller than the draft hood outlet diameter. Where a vent connector size(s) determined from the tables for a fan-assisted appliance(s) is smaller than the flue collar diameter, the use of the smaller size(s) shall be permitted provided that the installation complies with all of the following conditions:

1. Vent connectors for fan-assisted appliance flue collars 12 inches (305 mm) in diameter or smaller are not reduced by more than one table size [e.g., 12 inches to 10 inches (305 mm to 254 mm) is a one-size reduction] and those larger than 12 inches (305 mm) in diameter are not reduced more than two table sizes [e.g., 24 inches to 20 inches (610 mm to 508 mm) is a two-size reduction].

2. The fan-assisted appliance(s) is common vented with a draft-hood-equipped appliance(s).

3. The vent connector has a smooth interior wall.

2428.3.18 Component commingling. All combinations of pipe sizes, single-wall, and double-wall metal pipe shall be allowed within any connector run(s) or within the common vent, provided all of the appropriate tables permit all of the desired sizes and types of pipe, as if they were used for the entire length of the subject connector or vent. Where single-wall and Type B double-wall metal pipes are used for vent connectors within the same venting system, the common vent must be sized using Table 2428.3(2) or 2428.3(4), as appropriate.

2428.3.19 Draft hood conversion accessories. Draft hood conversion accessories for use with masonry chimneys venting listed Category I fan-assisted appliances shall be listed and installed in accordance with the manufacturer's installation instructions for such listed accessories.

2428.3.20 Multiple sizes permitted. Where a table permits more than one diameter of pipe to be used for a connector or vent, all the permitted sizes shall be permitted to be used.

2428.3.21 Table interpolation. Interpolation shall be permitted in calculating capacities for vent dimensions that fall between table entries.

2428.3.22 Extrapolation prohibited. Extrapolation beyond the table entries shall not be permitted.

2428.3.23 Engineering calculations. For vent heights less than 6 feet (1829 mm) and greater than shown in the tables, engineering methods shall be used to calculate vent capacities.

SECTION 2429

DIRECT-VENT, INTEGRAL VENT, MECHANICAL VENT AND VENTILATION/EXHAUST HOOD VENTING

2429.1 General. The installation of direct-vent and integral vent appliances shall be in accordance with Section 2427. Mechanical venting systems shall be designed and installed in accordance with Section 2427.

SECTION 2430

FACTORY-BUILT CHIMNEYS

2430.1 Listing. Factory-built chimneys for building heating appliances producing flue gases having a temperature not greater than 1,000°F (538°C), measured at the entrance to the chimney, shall be listed and labeled in accordance with UL 103 and shall be installed and terminated in accordance with the manufacturer's installation instructions.

2430.2 Support. Where factory-built chimneys are supported by structural members, such as joists and rafters, such members shall be designed to support the additional load.

SECTION 2431

GENERAL

2431.1 Scope. Sections 2432 through 2453 shall govern the approval, design, installation, construction, maintenance, alteration and repair of the appliances and equipment specifically identified herein.

SECTION 2432

DECORATIVE APPLIANCES FOR INSTALLATION IN FIREPLACES

2432.1 General. Decorative appliances for installation in approved solid fuel burning fireplaces shall be tested in accordance with ANSI Z 21.60 and shall be installed in accordance with the manufacturer's installation instructions. Manually lighted natural gas decorative appliances shall be tested in accordance with ANSI Z 21.84.

2432.2 Flame safeguard device. Decorative appliances for installation in approved solid fuel-burning fireplaces, with the exception of those tested in accordance with ANSI Z 21.84, shall utilize a direct ignition device, an ignitor or a pilot flame to ignite the fuel at the main burner, and shall be equipped with a flame safeguard device. The flame safeguard device shall automatically shut off the fuel supply to a main burner or group of burners when the means of ignition of such burners becomes inoperative.

2432.3 Prohibited installations. Decorative appliances for installation in fireplaces shall not be installed where prohibited by Section 2406.2.

SECTION 2433

LOG LIGHTERS

2433.1 General. Log lighters shall be tested in accordance with CSA 8 and shall be installed in accordance with the manufacturer's installation instructions.

SECTION 2434

VENTED GAS FIREPLACES (DECORATIVE APPLIANCES)

2434.1 General. Vented gas fireplaces shall be tested in accordance with ANSI Z 21.50, shall be installed in accordance with the manufacturer's installation instructions and shall be designed and equipped as specified in Section 2432.2.

2434.2 Access. Panels, grilles, and access doors that are required to be removed for normal servicing operations shall not be attached to the building.

SECTION 2435

VENTED GAS FIREPLACE HEATERS

2435.1 General. Vented gas fireplace heaters shall be installed in accordance with the manufacturer's installation instructions, shall be tested in accordance with ANSI Z 21.88 and shall be designed and equipped as specified in Section 2432.2.

SECTION 2436

VENTED WALL FURNACES

2436.1 General. Vented wall furnaces shall be tested in accordance with ANSI Z 21.86 /CSA 2.32 and shall be installed in accordance with the manufacturer's installation instructions.

2436.2 Venting. Vented wall furnaces shall be vented in accordance with Section 2427.

2436.3 Location. Vented wall furnaces shall be located so as not to cause a fire hazard to walls, floors, combustible furnishings or doors. Vented wall furnaces installed between bathrooms and adjoining rooms shall not circulate air from bathrooms to other parts of the building.

2436.4 Door swing. Vented wall furnaces shall be located so that a door cannot swing within 12 inches (305 mm) of an air inlet or air outlet of such furnace measured at right angles to the opening. Doorstops or door closers shall not be installed to obtain this clearance.

2436.5 Ducts prohibited. Ducts shall not be attached to wall furnaces. Casing extension boots shall not be installed unless listed as part of the appliance.

2436.6 Access. Vented wall furnaces shall be provided with access for cleaning of heating surfaces, removal of burners, replacement of sections, motors, controls, filters and other working parts, and for adjustments and lubrication of parts requiring such attention. Panels, grilles and access doors that are required to be removed for normal servicing operations shall not be attached to the building construction.

SECTION 2437

FLOOR FURNACES

2437.1 General. Floor furnaces shall be tested in accordance with ANSI Z 21.86 /CSA 2.32 and shall be installed in accordance with the manufacturer's installation instructions.

2437.2 Placement. The following provisions apply to floor furnaces:

1. Floors. Floor furnaces shall not be installed in the floor of any doorway, stairway landing, aisle or passageway of any enclosure, public or private, or in an exitway from any such room or space.

2. Walls and corners. The register of a floor furnace with a horizontal warm air outlet shall not be placed closer than 6 inches (152 mm) to the nearest wall. A distance of at least 18 inches (457 mm) from two adjoining sides of the floor furnace register to walls shall be provided to eliminate the necessity of occupants walking over the warm air discharge. The remaining sides shall be permitted to be placed not closer than 6 inches (152 mm) to a wall. Wall-register models shall not be placed closer than 6 inches (152 mm) to a corner.

3. Draperies. The furnace shall be placed so that a door, drapery, or similar object cannot be nearer than 12 inches (305 mm) to any portion of the register of the furnace.

4. Floor construction. Floor furnaces shall not be installed in concrete floor construction built on grade.

5. Thermostat. The controlling thermostat for a floor furnace shall be located within the same room or space as the floor furnace or shall be located in an adjacent room or space that is permanently open to the room or space containing the floor furnace.

2437.3 Bracing. The floor around the furnace shall be braced and headed with a support framework designed in accordance with Chapter 5.

2437.4 Clearance. The lowest portion of the floor furnace shall have not less than a 6-inch (152 mm) clearance from the grade level; except where the lower 6-inch (152 mm) portion of the floor furnace is sealed by the manufacturer to prevent entrance of water, the minimum clearance shall be reduced to not less than 2 inches (51 mm). Where these clearances cannot be provided, the ground below and to the sides shall be excavated to form a pit under the furnace so that the required clearance is provided beneath the lowest portion of the furnace. A 12-inch (305 mm) minimum clearance shall be provided on all sides except the control side, which shall have an 18-inch (457 mm) minimum clearance.

2437.5 First floor installation. Where the basement story level below the floor in which a floor furnace is installed is utilized as habitable space, such floor furnaces shall be enclosed as specified in Section 2437.6 and shall project into a nonhabitable space.

2437.6 Upper floor installations. Floor furnaces installed in upper stories of buildings shall project below into nonhabitable space and shall be separated from the nonhabitable space by an enclosure constructed of noncombustible materials. The floor furnace shall be provided with access, clearance to all sides and bottom of not less than 6 inches (152 mm) and combustion air in accordance with Section 2407.

SECTION 2438

CLOTHES DRYERS

2438.1 General. Clothes dryers shall be tested in accordance with ANSI Z21.5.1 and shall be installed in accordance with the manufacturer's installation instructions.

SECTION 2439

CLOTHES DRYER EXHAUST

2439.1 Installation. Clothes dryers shall be exhausted in accordance with the manufacturer's instructions. Dryer exhaust systems shall be independent of all other systems and shall convey the moisture and any products of combustion to the outside of the building.

2439.2 Duct penetrations. Ducts that exhaust clothes dryers shall not penetrate or be located within any fireblocking, draftstopping or any wall, floor/ceiling or other assembly required by this code to be fire-resistance rated, unless such duct is constructed of galvanized steel or aluminum of the thickness specified in the mechanical provisions of this code and the fire-resistance rating is maintained in accordance with this code. Fire dampers shall not be installed in clothes dryer exhaust duct systems.

2439.3 Exhaust installation. Dryer exhaust ducts for clothes dryers shall terminate on the outside of the building and shall be equipped with a backdraft damper. Screens shall not be installed at the duct termination. Ducts shall not be connected or installed with sheet metal screws or other fasteners that will obstruct the flow. Clothes dryer exhaust ducts shall not be connected to a vent connector, vent or chimney. Clothes dryer exhaust ducts shall not extend into or through ducts or plenums.

2439.4 Makeup air. Installations exhausting more than 200 cfm ( 0.09 m3/s) shall be provided with makeup air. Where a closet is designed for the installation of a clothes dryer, an opening having an area of not less than 100 square inches ( 0.0645 m2) for makeup air shall be provided in the closet enclosure, or makeup air shall be provided by other approved means.

2439.5 Domestic clothes dryer exhaust ducts. Exhaust ducts for domestic clothes dryers shall conform to the requirements of Sections 2439.5.1 through 2439.5.7.

2439.5.1 Material and size. Exhaust ducts shall have a smooth interior finish and shall be constructed of metal a minimum 0.016 -inch ( 0.4 mm) thick. The exhaust duct size shall be 4 inches (102 mm) nominal in diameter.

2439.5.2 Duct installation. Exhaust ducts shall be supported at 4 foot (1219 mm) intervals and secured in place. The insert end of the duct shall extend into the adjoining duct or fitting in the direction of airflow. Ducts shall not be joined with screws or similar fasteners that protrude into the inside of the duct.

2439.5.3 Protection required. Protective shield plates shall be placed where nails or screws from finish or other work are likely to penetrate the clothes dryer exhaust duct. Shield plates shall be placed on the finished face of all framing members where there is less than 11/4 inches (32 mm) between the duct and the finished face of the framing member. Protective shield plates shall be constructed of steel, shall have a minimum thickness of 0.062 inch ( 1.6 mm)

2439.5.4 Transition ducts. Transition ducts used to connect the dryer to the exhaust duct system shall be a single length that is listed and labeled in accordance with UL 2158A. Transition ducts shall be a maximum of 8 feet (2438 mm) in length and shall not be concealed within construction.

2439.5.5 Duct length. The maximum allowable exhaust duct length shall be determined by one of the methods specified in Section 2439.5.5.1 or 2439.5.5.2.

2439.5.5.1 Specified length. The maximum length of the exhaust duct shall be 25 feet (7620 mm) from the connection to the transition duct from the dryer to the outlet terminal. Where fittings are used, the maximum length of the exhaust duct shall be reduced in accordance with Table 2439.5.5.1.

2439.5.5.2 Manufacturer's instructions. The maximum length of the exhaust duct shall be determined by the dryer manufacturer's installation instructions. The building official shall be provided with a copy of the installation instructions for the make and model of the dryer. Where the exhaust duct is to be concealed, the installation instructions shall be provided to the building official prior to the concealment inspection. In the absence of fitting equivalent length calculations from the clothes dryer manufacturer, Table 2439.5.5.1 shall be used.

2439.5.6 Length identification. Where the exhaust duct is concealed within the building construction, and only if the equivalent length exceeds 25 feet (7620 mm), the equivalent length of the exhaust duct shall be identified on a permanent label or tag. The label or tag shall be located within 6 feet (1829 mm) of the exhaust duct connection or at the electrical panel.

2439.5.7 Exhaust duct required. Where space for a clothes dryer is provided, an exhaust duct system shall be installed. Where the clothes dryer is not installed at the time of occupancy, the exhaust duct shall be capped at location of the future dryer.

Exception: Where a listed condensing clothes dryer is installed prior to occupancy of the structure.

SECTION 2440

SAUNA HEATERS

2440.1 General. Sauna heaters shall be installed in accordance with the manufacturer's installation instructions.

2440.2 Location and protection. Sauna heaters shall be located so as to minimize the possibility of accidental contact by a person in the room.

2440.2.1 Guards. Sauna heaters shall be protected from accidental contact by an approved guard or barrier of material having a low coefficient of thermal conductivity. The guard shall not substantially affect the transfer of heat from the heater to the room.

2440.3 Access. Panels, grilles and access doors that are required to be removed for normal servicing operations, shall not be attached to the building.

2440.4 Combustion and dilution air intakes. Sauna heaters of other than the direct-vent type shall be installed with the draft hood and combustion air intake located outside the sauna room. Where the combustion air inlet and the draft hood are in a dressing room adjacent to the sauna room, there shall be provisions to prevent physically blocking the combustion air inlet and the draft hood inlet, and to prevent physical contact with the draft hood and vent assembly, or warning notices shall be posted to avoid such contact. Any warning notice shall be easily readable, shall contrast with its background, and the wording shall be in letters not less than 0.25 inch ( 6.4 mm) high.

TABLE 2439.5.5.1

DRYER EXHAUST DUCT FITTING EQUIVALENT LENGTH

DRYER EXHAUST DUCT FITTING TYPE EQUIVALENT LENGTH
4 inch radius mitered 45 degree elbow 2 feet 6 inches
4 inch radius mitered 90 degree elbow 5 feet
6 inch radius smooth 45 degree elbow 1 foot
6 inch radius smooth 90 degree elbow 1 foot 9 inches
8 inch radius smooth 45 degree elbow 1 foot
8 inch radius smooth 90 degree elbow 1 foot 7 inches
10 inch radius smooth 45 degree elbow 9 inches
10 inch radius smooth 90 degree elbow 1 foot 6 inches

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 degree = 0.0175 rad.

2440.5 Combustion and ventilation air. Combustion air shall not be taken from inside the sauna room. Combustion and ventilation air for a sauna heater not of the direct-vent type shall be provided to the area in which the combustion air inlet and draft hood are located in accordance with Section 2407.

2440.6 Heat and time controls. Sauna heaters shall be equipped with a thermostat which will limit room temperature to 194°F (90°C). If the thermostat is not an integral part of the sauna heater, the heat-sensing element shall be located within 6 inches (152 mm) of the ceiling. If the heat-sensing element is a capillary tube and bulb, the assembly shall be attached to the wall or other support, and shall be protected against physical damage.

2440.6.1 Timers. A timer, if provided to control main burner operation, shall have a maximum operating time of 1 hour. The control for the timer shall be located outside the sauna room.

2440.7 Sauna room. A ventilation opening into the sauna room shall be provided. The opening shall be not less than 4 inches by 8 inches (102 mm by 203 mm) located near the top of the door into the sauna room.

SECTION 2441

POOL AND SPA HEATERS

2441.1 General. Where regulations are adopted and enforced by the local jurisdiction, heaters for residential swimming pools and spas shall be tested in accordance with ANSI Z 21.56 and shall be installed in accordance with the manufacturer's installation instructions.

SECTION 2442

FORCED-AIR WARM-AIR FURNACES

2442.1 General. Forced-air warm-air furnaces shall be tested in accordance with ANSI Z 21.47 or UL 795 and shall be installed in accordance with the manufacturer's installation instructions.

2442.2 Forced-air furnaces. The minimum unobstructed total area of the outside and return air ducts or openings to a forced-air warm-air furnace shall be not less than 2 square inches for each 1,000 Btu/h (4402 mm2/W) output rating capacity of the furnace and not less than that specified in the furnace manufacturer's installation instructions. The minimum unobstructed total area of supply ducts from a forced-air warm-air furnace shall be not less than 2 square inches for each 1,000 Btu/h (4402 mm2/W) output rating capacity of the furnace and not less than that specified in the furnace manufacturer's installation instructions.

Exception: The total area of the supply air ducts and outside and return air ducts shall not be required to be larger than the minimum size required by the furnace manufacturer's installation instructions.

2442.3 Dampers. Volume dampers shall not be placed in the air inlet to a furnace in a manner that will reduce the required air to the furnace.

2442.4 Circulating air ducts for forced-air warm-air furnaces. Circulating air for forced-air-type, warm-air furnaces shall be conducted into the blower housing from outside the furnace enclosure by continuous air-tight ducts.

2442.5 Prohibited sources. Outside or return air for a forced-air heating system shall not be taken from the following locations:

1. Closer than 10 feet (3048 mm) from an appliance vent outlet, a vent opening from a plumbing drainage system or the discharge outlet of an exhaust fan, unless the outlet is 3 feet (914 mm) above the outside air inlet.

2. Where objectionable odors, fumes or flammable vapors are present; or where located less than 10 feet (3048 mm) above the surface of any abutting public way or driveway; or where located at grade level by a sidewalk, street, alley or driveway.

3. A hazardous or insanitary location or a refrigeration machinery room as defined in the Ohio Mechanical Code.

4. A room or space, the volume of which is less than 25 percent of the entire volume served by such system. Where connected by a permanent opening having an area sized in accordance with Section 2442.2, adjoining rooms or spaces shall be considered as a single room or space for the purpose of determining the volume of such rooms or spaces.

Exception: The minimum volume requirement shall not apply where the amount of return air taken from a room or space is less than or equal to the amount of supply air delivered to that room or space.

5. A room or space containing an appliance where such a room or space serves as the sole source of return air.

Exception: This shall not apply where:

1. The appliance is a direct-vent appliance or an appliance not requiring a vent in accordance with Section 2425.8.

2. The room or space complies with the following requirements:

2.

1. The return air shall be taken from a room or space having a volume exceeding 1 cubic foot for each 10 Btu/h ( 9.6 L/W) of combined input rating of all fuel-burning appliances therein.

2.

2. The volume of supply air discharged back into the same space shall be approximately equal to the volume of return air taken from the space.

2.

3. Return-air inlets shall not be located within 10 feet (3048 mm) of any appliance firebox or draft hood in the same room or space.

3. Rooms or spaces containing solid-fuel-burning appliances, provided that return-air inlets are located not less than 10 feet (3048 mm) from the firebox of such appliances.

6. A closet, bathroom, toilet room, kitchen, garage, mechanical room, boiler room, furnace room or attic.

Exception: Where return air intakes are located not less than 10 feet (3048 mm) from cooking appliances, and serve only the kitchen area, taking return air from a kitchen area shall not be prohibited.

7. A crawl space by means of direct connection to the return side of a forced air system. Transfer openings in the crawl space enclosure shall not be prohibited.

2442.6 Screen. Required outdoor air inlets shall be covered with a screen having 1/4-inch ( 6.4 mm) openings. Required outdoor air inlets serving a nonresidential portion of a building shall be covered with screen having openings larger than 1/4 inch ( 6.4 mm) and not larger than 1 inch (25 mm).

2442.7 Return-air limitation. Return air from one dwelling unit shall not be discharged into another dwelling unit.

2442.8 Furnace plenums and air ducts. Where a furnace is installed so that supply ducts carry air circulated by the furnace to areas outside of the space containing the furnace, the return air shall also be handled by a duct(s) sealed to the furnace casing and terminating outside of the space containing the furnace.

SECTION 2443

CONVERSION BURNERS

2443.1 Conversion burners. The installation of conversion burners shall conform to ANSI Z 21.8.

SECTION 2444

UNIT HEATERS

2444.1 General. Unit heaters shall be tested in accordance with ANSI Z 83.8 and shall be installed in accordance with the manufacturer's installation instructions.

2444.2 Support. Suspended-type unit heaters shall be supported by elements that are designed and constructed to accommodate the weight and dynamic loads. Hangers and brackets shall be of noncombustible material.

2444.3 Ductwork. Ducts shall not be connected to a unit heater unless the heater is listed for such installation.

2444.4 Clearance. Suspended-type unit heaters shall be installed with clearances to combustible materials of not less than 18 inches (457 mm) at the sides, 12 inches (305 mm) at the bottom and 6 inches (152 mm) above the top where the unit heater has an internal draft hood or 1 inch (25 mm) above the top of the sloping side of the vertical draft hood.

Floor-mounted-type unit heaters shall be installed with clearances to combustible materials at the back and one side only of not less than 6 inches (152 mm). Where the flue gases are vented horizontally, the 6-inch (152 mm) clearance shall be measured from the draft hood or vent instead of the rear wall of the unit heater. Floor-mounted-type unit heaters shall not be installed on combustible floors unless listed for such installation.

Clearance for servicing all unit heaters shall be in accordance with the manufacturer's installation instructions.

Exception: Unit heaters listed for reduced clearance shall be permitted to be installed with such clearances in accordance with their listing and the manufacturer's instructions.

SECTION 2445

UNVENTED ROOM HEATERS

2445.1 General. Unvented room heaters shall be tested in accordance with ANSI Z 21.11.2 and shall be installed in accordance with the conditions of the listing and the manufacturer's installation instructions.

2445.2 Prohibited use. One or more unvented room heaters shall not be used as the sole source of comfort heating in a dwelling unit.

2445.3 Input rating. Unvented room heaters shall not have an input rating in excess of 40,000 Btu/h ( 11.7 kW).

2445.4 Prohibited locations. The location of unvented room heaters shall comply with Section 2406.2.

2445.5 Room or space volume. The aggregate input rating of all unvented appliances installed in a room or space shall not exceed 20 Btu/h per cubic foot ( 0.21 kW/m3) of volume of such room or space. Where the room or space in which the appliance is installed is directly connected to another room or space by a doorway, archway or other opening of comparable size that cannot be closed, the volume of such adjacent room or space shall be permitted to be included in the calculations.

2445.6 Oxygen-depletion safety system. Unvented room heaters shall be equipped with an oxygen-depletion-sensitive safety shutoff system. The system shall shut off the gas supply to the main and pilot burners when the oxygen in the surrounding atmosphere is depleted to the percent concentration specified by the manufacturer, but not lower than 18 percent. The system shall not incorporate field adjustment means capable of changing the set point at which the system acts to shut off the gas supply to the room heater.

2445.7 Unvented decorative room heaters. An unvented decorative room heater shall not be installed in a factory-built fireplace unless the fireplace system has been specifically tested, listed and labeled for such use in accordance with UL 127.

2445.7.1 Ventless firebox enclosures. Ventless firebox enclosures used with unvented decorative room heaters shall be listed as complying with ANSI Z 21.91.

SECTION 2446

VENTED ROOM HEATERS

2446.1 General. Vented room heaters shall be tested in accordance with ANSI Z 21.86 /CSA 2.32, shall be designed and equipped as specified in Section 2432.2 and shall be installed in accordance with the manufacturer's installation instructions.

SECTION 2447

COOKING APPLIANCES

2447.1 Cooking appliances. Cooking appliances that are designed for permanent installation, including ranges, ovens, stoves, broilers, grills, fryers, griddles, hot plates and barbecues, shall be tested in accordance with ANSI Z 21.1 or ANSI Z 21.58 and shall be installed in accordance with the manufacturer's installation instructions.

2447.2 Prohibited location. Cooking appliances designed, tested, listed and labeled for use in commercial occupancies shall not be installed within dwelling units or within any area where domestic cooking operations occur.

2447.3 Domestic appliances. Cooking appliances installed within dwelling units and within areas where domestic cooking operations occur shall be listed and labeled as household-type appliances for domestic use.

2447.4 Range installation. Ranges installed on combustible floors shall be set on their own bases or legs and shall be installed with clearances of not less than that shown on the label.

2447.5 Vertical clearance above cooking top. Household cooking appliances shall have a vertical clearance above the cooking top of not less than 30 inches (760 mm) to combustible material and metal cabinets. A minimum clearance of 24 inches (610 mm) is permitted where one of the following is installed:

1. The underside of the combustible material or metal cabinet above the cooking top is protected with not less than 1/4 inch (6 mm) thick insulating millboard covered with sheet metal not less than 0.0122 inch ( 0.3 mm) thick.

2. A metal ventilating hood constructed of sheet metal not less than 0.0122 inch ( 0.3 mm) thick is installed above the cooking top with a clearance of not less than 1/4 inch (6 mm) between the hood and the underside of the combustible material or metal cabinet. The hood shall have a width not less than the width of the appliance and shall be centered over the appliance.

3. A listed cooking appliance or microwave oven is installed over a listed cooking appliance and in compliance with the terms of the manufacturer's installation instructions for the upper appliance.

SECTION 2448

WATER HEATERS

2448.1 General. Water heaters shall be tested in accordance with ANSI Z 21.10.1 and ANSI Z 21.10.3 and shall be installed in accordance with the manufacturer's installation instructions.

2448.1.1 Installation requirements. The requirements for water heaters relative to sizing, relief valves, drain pans and scald protection shall be in accordance with this code.

2448.2 Water heaters utilized for space heating. Water heaters utilized both to supply potable hot water and provide hot water for space-heating applications shall be listed and labeled for such applications by the manufacturer and shall be installed in accordance with the manufacturer's installation instructions and this code.

SECTION 2449

AIR CONDITIONING APPLIANCES

2449.1 General. Air conditioning appliances shall be tested in accordance with ANSI Z21.40.1 or ANSI Z21.40.2 and shall be installed in accordance with the manufacturer's installation instructions.

2449.2 Independent piping. Gas piping serving heating appliances shall be permitted to also serve cooling appliances where such heating and cooling appliances cannot be operated simultaneously. (See Section 2413.)

2449.3 Connection of gas engine-powered air conditioners. To protect against the effects of normal vibration in service, gas engines shall not be rigidly connected to the gas supply piping.

2449.4 Installation. Air conditioning appliances shall be installed in accordance with the manufacturer's instructions. Unless the appliance is listed for installation on a combustible surface such as a floor or roof, or unless the surface is protected in an approved manner, the appliance shall be installed on a surface of noncombustible construction with noncombustible material and surface finish and with no combustible material against the underside thereof.

SECTION 2450

ILLUMINATING APPLIANCES

2450.1 General. Illuminating appliances shall be tested in accordance with ANSI Z 21.42 and shall be installed in accordance with the manufacturer's installation instructions.

2450.2 Mounting on buildings. Illuminating appliances designed for wall or ceiling mounting shall be securely attached to substantial structures in such a manner that they are not dependent on the gas piping for support.

2450.3 Mounting on posts. Illuminating appliances designed for post mounting shall be securely and rigidly attached to a post. Posts shall be rigidly mounted. The strength and rigidity of posts greater than 3 feet (914 mm) in height shall be at least equivalent to that of a 2.5 -inch-diameter (64 mm) post constructed of 0.064 -inch-thick ( 1.6 mm) steel or a 1-inch (25 mm) Schedule 40 steel pipe. Posts 3 feet (914 mm) or less in height shall not be smaller than 3/4-inch ( 19.1 mm) Schedule 40 steel pipe. Drain openings shall be provided near the base of posts where there is a possibility of water collecting inside them.

2450.4 Appliance pressure regulators. Where an appliance pressure regulator is not supplied with an illuminating appliance and the service line is not equipped with a service pressure regulator, an appliance pressure regulator shall be installed in the line to the illuminating appliance. For multiple installations, one regulator of adequate capacity shall be permitted to serve more than one illuminating appliance.

SECTION 2451

INFRARED RADIANT HEATERS

2451.1 General. Infrared radiant heaters shall be tested in accordance with ANSI Z 83.6 and shall be installed in accordance with the manufacturer's installation instructions.

2451.2 Support. Infrared radiant heaters shall be fixed in a position independent of gas and electric supply lines. Hangers and brackets shall be of noncombustible material.

SECTION 2452

BOILERS

2452.1 Standards. Boilers shall be listed in accordance with the requirements of ANSI Z 21.13 or UL 795. If applicable, the boiler shall be designed and constructed in accordance with the requirements of ASME CSD-1 and as applicable, the ASME Boiler and Pressure Vessel Code, Sections I, II, IV, V and IX and NFPA 85.

2452.2 Installation. In addition to the requirements of this code, the installation of boilers shall be in accordance with the manufacturer's instructions and this code. Operating instructions of a permanent type shall be attached to the boiler. Boilers shall have all controls set, adjusted and tested by the installer. A complete control diagram together with complete boiler operating instructions shall be furnished by the installer. The manufacturer's rating data and the nameplate shall be attached to the boiler.

2452.3 Clearance to combustible material. Clearances to combustible materials shall be in accordance with Section 2409.4.

SECTION 2453

CHIMNEY DAMPER OPENING AREA

2453.1 Free opening area of chimney dampers. Where an unlisted decorative appliance for installation in a vented fireplace is installed, the fireplace damper shall have a permanent free opening equal to or greater than specified in Table 2453.1.

TABLE 2453.1

FREE OPENING AREA OF CHIMNEY DAMPER FOR VENTING FLUE GASES FROM UNLISTED DECORATIVE APPLIANCES FOR INSTALLATION IN VENTED FIREPLACES

CHIMNEY HEIGHT (feet) MINIMUM PERMANENT FREE OPENING (square inches)a
8 13 20 29 39 51 64
Appliance input rating (Btu per hour)
6 7,800 14,000 23,200 34,000 46,400 62,400 80,000
8 8,400 15,200 25,200 37,000 50,400 68,000 86,000
10 9,000 16,800 27,600 40,400 55,800 74,400 96,400
15 9,800 18,200 30,200 44,600 62,400 84,000 108,800
20 10,600 20,200 32,600 50,400 68,400 94,000 122,200
30 11,200 21,600 36,600 55,200 76,800 105,800 138,600

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square inch = 645.16 mm2, 1,000 Btu per hour = 0.293 kW.

a. The first six minimum permanent free openings (8 square inches to 51 square inches) correspond approximately to the cross-sectional areas of chimneys having diameters of 3 inches through 8 inches, respectively. The 64-square inch opening corresponds to the cross-sectional area of standard 8-inch by 8-inch chimney tile.

Replaces: 4101:8-24-03, 4101:8-24- 06.2

Effective: 01/01/2013
R.C. 119.032 review dates: 01/01/2018
Promulgated Under: 119.03
Statutory Authority: 3781.10(A) , 4104.43(A)(1)
Rule Amplifies: 3781.01 , 3781.06 , 3781.10 , 3781.11 , 3791.04 , 4740.14
Prior Effective Dates: 5/27/06