The text of this chapter is extracted from the 2018 edition of the International Fuel Gas Code and has been modified where necessary to conform to the scope of application of the International Residential Code for One- and Two-Family Dwellings. The section numbers appearing in parentheses after each section number are the section numbers of the corresponding text in the International Fuel Gas Code.
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- and two-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:
- Liquefied natural gas (LNG) installations.
- Temporary LP-gas piping for buildings under construction or renovation that is not to become part of the permanent piping system.
- 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.
- Portable LP-gas appliances and equipment of all types that is not connected to a fixed fuel piping system.
- Portable fuel cell appliances that are neither connected to a fixed piping system nor interconnected to a power grid.
- Installation of hydrogen gas, LP-gas and compressed natural gas (CNG) systems on vehicles.
Unless otherwise expressly stated, the following words and terms shall, for the purposes of this chapter, have the meanings indicated in this chapter.
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.
Where terms are not defined in this code and are defined in the International Building Code, International Fire Code, International Mechanical Code, International Fuel Gas Code or International Plumbing Code, such terms shall have meanings ascribed to them as in those codes.
ACCESS (TO). That which enables a device, appliance or equipment to be reached by ready access or by a means that first requires the removal or movement of a panel, door or similar obstruction (see also "Ready access").
AIR CONDITIONER, GAS-FIRED. A gas-burning, automatically operated appliance for supplying cooled air, dehumidified air, or both, or chilled liquid.
AIR CONDITIONING. The treatment of air so as to control simultaneously the temperature, humidity, cleanness and distribution of the air to meet the requirements of a conditioned space.
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. Any combination of outdoor and transfer air intended to replace exhaust air and exfiltration.
ALTERATION. A change in a system that involves an extension, addition or change to the arrangement, type or purpose of the original 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 utilizes a fuel or a raw material as a fuel to produce light, heat, power, refrigeration or air conditioning. Also, an apparatus that compresses fuel gases.
APPLIANCE, AUTOMATICALLY CONTROLLED. Appliances equipped with an automatic burner ignition and safety shutoff device and other automatic devices, that accomplish complete turn-on and shutoff of the gas to the main burner or burners, and graduate the gas supply to the burner or burners, but do not affect complete shutoff 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. Acceptable to the code official.
APPROVED AGENCY. An established and recognized agency that is regularly engaged in conducting tests, furnishing inspection services or furnishing certification, where such agency has been approved by the code official.
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.
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 pounds per square inch gauge (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).
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. These regulations, subsequent amendments thereto, or any emergency rule or regulation that the administrative authority having jurisdiction has lawfully adopted.
CODE OFFICIAL. The officer or other designated authority charged with the administration and enforcement of this code, or a duly authorized representative.
COMBUSTIBLE ASSEMBLY. Wall, floor, ceiling or other assembly constructed of one or more component materials that are not defined as noncombustible.
COMBUSTIBLE MATERIAL. Any material not defined as noncombustible.
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.
COMBUSTION PRODUCTS. Constituents resulting from the combustion of a fuel with the oxygen of the air, including the inert gases, but excluding excess air.
CONCEALED LOCATION. A location that cannot be accessed without damaging permanent parts of the building structure or finish surface. Spaces above, below or behind readily removable panels or doors shall not be considered as concealed.
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.
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 APPLIANCE, VENTED. A vented appliance wherein the primary function lies in the aesthetic effect of the flames.
DECORATIVE 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. In areas designated as Zone AO, the design flood elevation shall be the elevation of the highest existing grade of the building's perimeter plus the depth number (in feet) specified on the flood hazard map. In areas designated as Zone AO where a depth number is not specified on the map, the depth number shall be taken as being equal to 2 feet (610 mm).
DIRECT-VENT APPLIANCES. Appliances that are constructed and installed so that all air for combustion is derived directly from the outside atmosphere and all flue gases are discharged directly 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: provide for ready escape of the flue gases from the appliance in the event of no draft, backdraft, or stoppage beyond the draft hood; prevent a backdraft from entering the appliance; and 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.
EQUIPMENT. Apparatus and devices other than appliances.
EXCESS FLOW VALVE (EFV). A valve designed to activate when the fuel gas passing through it exceeds a prescribed flow rate.
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.
Factory-built fireplace. A fireplace composed of listed factory-built components assembled in accordance with the terms of listing to form the completed fireplace.
Masonry fireplace. A hearth and fire chamber of solid masonry units such as bricks, stones, listed masonry units or reinforced concrete, provided with a suitable chimney.
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.
FLASHBACK ARRESTOR CHECK VALVE. A device that will prevent the backflow of one gas into the supply system of another gas and prevent the passage of flame into the gas supply system.
FLOOD HAZARD AREA. The greater of the following two areas:
- The area within a floodplain subject to a 1 percent or greater chance of flooding in any given year.
- 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 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.
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 that 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 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. The location is not necessarily categorized in the International Building Code as a high-hazard use group classification.
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 that 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 a press-connect joint, 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 that forms a continuous bond between the mating surfaces without dissolving either one of them.
LABELED. Equipment, materials or products to which have been affixed a label, seal, symbol or other identifying mark of a nationally recognized testing laboratory, inspection agency or other organization concerned with product evaluation that maintains periodic inspection of the production of the above-labeled items and whose labeling indicates either that the equipment, material or product meets identified standards or has been tested and found suitable for a specified purpose.
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.
LISTED. Equipment, materials, products or services included in a list published by an organization acceptable to the code official and concerned with evaluation of products or services that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services and whose listing states either that the equipment, material, product or service meets identified standards or has been tested and found suitable for a specified purpose.
LIVING SPACE. Space within a dwelling unit utilized for living, sleeping, eating, cooking, bathing, washing and sanitation purposes.
LOG LIGHTER. 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.
NONCOMBUSTIBLE MATERIALS. Materials that, where tested in accordance with ASTM E136, have not fewer than three of four specimens tested meeting all of the following criteria:
- The recorded temperature of the surface and interior thermocouples shall not at any time during the test rise more than 54°F (30°C) above the furnace temperature at the beginning of the test.
- There shall not be flaming from the specimen after the first 30 seconds.
- If the weight loss of the specimen during testing exceeds 50 percent, the recorded temperature of the surface and interior thermocouples shall not at any time during the test rise above the furnace air temperature at the beginning of the test, and there shall not be flaming of the specimen.
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.
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.
Pipe. A rigid conduit of iron, steel, copper, copper-alloy or plastic.
Tubing. Semirigid conduit of copper, copper-alloy, aluminum, plastic or steel.
PIPING SYSTEM. The 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 service pressure regulator, exclusive of line gas regulators, in the system.
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.
PURGE. To free a gas conduit of air or gas, or a mixture of gas and air.
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. For natural gas systems, a device installed by the serving gas supplier to reduce and limit the service line pressure to delivery pressure. For undiluted liquefied petroleum gas systems, the regulator located upstream from all line gas pressure regulators, where installed, and downstream from any first stage or a high pressure regulator in the system.
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 that opens and closes a relief vent, depending on whether the pressure is above or below a predetermined value.
Manual reset type. A valve that automatically opens a relief vent at a predetermined temperature and that must be manually returned to the closed position.
Reseating or self-closing type. An automatic valve that 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.
ROOM HEATER, UNVENTED. See "Unvented room heater."
ROOM HEATER, VENTED. A free-standing heating unit used for direct heating of the space in and adjacent to that in which the unit is located. (See "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.
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.
THIRD-PARTY CERTIFICATION AGENCY. An approved agency operating a product or material certification system that incorporates initial product testing, assessment and surveillance of a manufacturer's quality control system.
THIRD-PARTY CERTIFIED. Certification obtained by the manufacturer indicating that the function and performance characteristics of a product or material have been determined by testing and ongoing surveillance by an approved third-party certification agency. Assertion of certification is in the form of identification in accordance with the requirements of the third-party certification agency.
THIRD-PARTY TESTED. Procedure by which an approved testing laboratory provides documentation that a product, material or system conforms to specified requirements.
TOILET, GAS-FIRED. A packaged and completely assembled appliance containing a toilet that incinerates refuse instead of flushing it away with water.
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. A self-contained, automatically controlled, vented, fuel-gas-burning, space-heating appliance, intended for installation in the space to be heated without the use of ducts, and having integral means for circulation of air.
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.
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 pilot or pilots that are provided with 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 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."
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 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 outdoor 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.
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 G2401.
The requirements for combustion and dilution air for gas-fired appliances shall be governed by Section G2407. The requirements for combustion and dilution air for appliances operating with fuels other than fuel gas shall be regulated by Chapter 17.
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 R104.11. The approval of unlisted appliances in accordance with Section R104.11 shall be based on approved engineering evaluation.
Defective material or parts shall be replaced or repaired in such a manner so as to preserve the original approval or listing.
Appliances and supports that are exposed to wind shall be designed and installed to resist the wind pressures determined in accordance with this code.
For structures located in flood hazard areas, the appliance, equipment and system installations regulated by this code shall be located at or above the elevation required by Section R322 for utilities and attendant equipment.
Exception: The appliance, equipment and system installations regulated by this code are permitted to be located below the elevation required by Section R322 for utilities and attendant equipment 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 such elevation.
Upcodes Diagrams
Where 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.
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.
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.
Condensate pumps located in uninhabitable spaces, such as attics and crawl spaces, shall be connected to the appliance or equipment served such that when the pump fails, the appliance or equipment will be prevented from operating. Pumps shall be installed in accordance with the manufacturer's instructions.
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 that is required to be changed or replaced shall be left in a safe structural condition in accordance with the requirements of this code.
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, such as HVAC equipment and water heaters, shall not be permitted without verification that the truss is capable of supporting such additional loading.
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.
Appliances shall be located as required by this section, specific requirements elsewhere in this code and the conditions of the equipment and appliance listing.
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:
- The appliance is a direct-vent appliance installed in accordance with the conditions of the listing and the manufacturer's instructions.
- 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 G2407.5.
- A single wall-mounted unvented room heater is installed in a bathroom and such unvented room heater is equipped as specified in Section G2445.6 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 G2407.5.
- A single wall-mounted unvented room heater is installed in a bedroom and such unvented room heater is equipped as specified in Section G2445.6 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 G2407.5.
- 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. Combustion air shall be taken directly from the outdoors in accordance with Section G2407.6.
- A clothes dryer is installed in a residential bathroom or toilet room having a permanent opening with an area of not less than 100 square inches (0.06 m2) that communicates with a space outside of a sleeping room, bathroom, toilet room or storage closet.
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.
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 G2407.5 through G2407.9. Where the requirements of Section G2407.5 are not met, outdoor air shall be introduced in accordance with one of the methods prescribed in Sections G2407.6 through G2407.9. Direct-vent appliances, gas appliances of other than natural draft design, vented gas appliances not designated as Category I and appliances equipped with power burners, 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 G2439.5.
Appliances shall be located so as not to interfere with proper circulation of combustion, ventilation and dilution air.
Where used, a draft hood or a barometric draft regulator shall be installed in the same room or enclosure as the appliance served to prevent any difference in pressure between the hood or regulator and the combustion air supply.
Where exhaust fans, clothes dryers and kitchen ventilation systems interfere with the operation of appliances, makeup air shall be provided.
The required volume of indoor air shall be determined in accordance with Section G2407.5.1 or G2407.5.2, except that where the air infiltration rate is known to be less than 0.40 air changes per hour (ACH), Section G2407.5.2 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 G2407.5.3, are considered to be part of the required volume.
The minimum required volume shall be 50 cubic feet per 1,000 Btu/h (4.8 m3/kW) of the appliance input rating.
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.
(Equation 24-1)
For fan-assisted appliances, calculate volume using Equation 24-2.
(Equation 24-2)
where:
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.
Openings used to connect indoor spaces shall be sized and located in accordance with Sections G2407.5.3.1 and G2407.5.3.2 (see Figure G2407.5.3).
FIGURE G2407.5.3 (304.5.3)
ALL AIR FROM INSIDE THE BUILDING (see Section G2407.5.3)
Where 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 permanent opening shall commence within 12 inches (305 mm) of the top and one permanent 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).
The volumes of spaces in different stories shall be considered to be communicating spaces where such spaces are connected by one or more permanent 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.
Outdoor combustion air shall be provided through opening(s) to the outdoors in accordance with Section G2407.6.1 or G2407.6.2. The minimum dimension of air openings shall be not less than 3 inches (76 mm).
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 G2407.6.1(1) and G2407.6.1(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 (1100 mm2/kW) of total input rating of all appliances in the enclosure [see Figure G2407.6.1(3)].
FIGURE G2407.6.1(1) [304.6.1(1)]
ALL AIR FROM OUTDOORS—INLET AIR FROM VENTILATED CRAWL SPACE AND OUTLET AIR TO VENTILATED ATTIC (see Section G2407.6.1)
For SI: 1 foot = 304.8 mm.
FIGURE G2407.6.1(2) [304.6.1(2)]
ALL AIR FROM OUTDOORS THROUGH VENTILATED ATTIC (see Section G2407.6.1)
FIGURE G2407.6.1(3) [304.6.1(3)]
ALL AIR FROM OUTDOORS (see Section G2407.6.1)
One permanent opening, commencing within 12 inches (305 mm) of the top of the enclosure, shall be provided. The appliance shall have clearances of not less than 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 G2407.6.2) 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.
FIGURE G2407.6.2 (304.6.2)
SINGLE COMBUSTION AIR OPENING, ALL AIR FROM OUTDOORS (see Section G2407.6.2)
The use of a combination of indoor and outdoor combustion air shall be in accordance with Sections G2407.7.1 through G2407.7.3.
Where used, openings connecting the interior spaces shall comply with Section G2407.5.3.
Outdoor opening(s) shall be located in accordance with Section G2407.6.
The outdoor opening(s) size shall be calculated in accordance with the following:
- The ratio of interior spaces shall be the available volume of all communicating spaces divided by the required volume.
- The outdoor size reduction factor shall be one minus the ratio of interior spaces.
- The minimum size of outdoor opening(s) shall be the full size of outdoor opening(s) calculated in accordance with Section G2407.6, multiplied by the reduction factor. The minimum dimension of air openings shall be not less than 3 inches (76 mm).
Engineered combustion air installations shall provide an adequate supply of combustion, ventilation and dilution air and shall be approved.
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.
Where exhaust fans are installed, makeup air shall be provided to replace the exhausted air.
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.
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.
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.
Combustion air ducts shall comply with all of the following:
- 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.
- Ducts shall terminate in an unobstructed space allowing free movement of combustion air to the appliances.
- Ducts shall serve a single enclosure.
- 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.
- Ducts shall not be screened where terminating in an attic space.
- Horizontal upper combustion air ducts shall not slope downward toward the source of combustion air.
- 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.
- 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.
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 instructions.
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. Manufacturer's 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 G2404.3 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 code official.
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.
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.
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 G2408.2.
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 instructions.
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 G2409. 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.
Appliances shall be supported and connected to the piping so as not to exert undue strain on the connections.
This section shall govern the reduction in required clearances to combustible materials, including gypsum board, and combustible assemblies for chimneys, vents, appliances, devices and equipment. Clearance requirements for air-conditioning equipment and central heating boilers and furnaces shall comply with Sections G2409.3 and G2409.4.
The allowable clearance reduction shall be based on one of the methods specified in Table G2409.2 or shall utilize a reduced clearance protective assembly listed and labeled in accordance with UL 1618. Where required clearances are not listed in Table G2409.2, 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 G2409.2(1) through 2409.2(3)].
NOTES:
| A | = | the clearance without protection. |
| B | = | the reduced clearance permitted in accordance with Table G2409.2. The protection applied to the construction using combustible material shall extend far enough in each direction to make "C" equal to "A." |
FIGURE G2409.2(1) [308.2(1)]
For SI: 1 inch = 25.4 mm.
FIGURE G2409.2(2) [308.2(2)]
WALL PROTECTOR CLEARANCE REDUCTION SYSTEM
For SI: 1 inch = 25.4 mm.
FIGURE G2409.2(3) [308.2(3)]
MASONRY CLEARANCE REDUCTION SYSTEM
TABLE G2409.2 (308.2)a through k
REDUCTION OF CLEARANCES WITH SPECIFIED FORMS OF PROTECTION
| TYPE OF PROTECTION APPLIED TO AND COVERING ALL SURFACES OF COMBUSTIBLE MATERIAL WITHIN THE DISTANCE SPECIFIED AS THE REQUIRED CLEARANCE WITH NO PROTECTION [see Figures G2409.2(1), G2409.2(2), and G2409.2(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 | ||||||||||
| 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. 1/2-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.
- Reduction of clearances from combustible materials shall not interfere with combustion air, draft hood clearance and relief, and accessibility of servicing.
- 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.
- Spacers and ties shall be of noncombustible material. A spacer or tie shall not be used directly opposite an appliance or connector.
- For all clearance reduction systems using a ventilated airspace, adequate provision for air circulation shall be provided as described [see Figures G2409.2(2) and G2409.2(3)].
- There shall be not less than 1 inch between clearance reduction systems and combustible walls and ceilings for reduction systems using ventilated airspace.
- 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.
- Mineral wool batts (blanket or board) shall have a density of 8 pounds per cubic foot and a minimum melting point of 1500°F.
- 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.
- There shall be not less than 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.
- Clearances and thicknesses are minimum; larger clearances and thicknesses are acceptable.
- Listed single-wall connectors shall be installed in accordance with the manufacturer's instructions.
Clearance requirements for indoor air-conditioning appliances shall comply with Sections G2409.3.1 through G2409.3.4.
Air-conditioning appliances shall be installed with clearances in accordance with the manufacturer's instructions.
Air-conditioning appliances 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 G2409.2 and such reduction is allowed by the manufacturer's instructions.
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.
Clearance requirements for central-heating boilers and furnaces shall comply with Sections G2409.4.1 through G2409.4.5. The clearance to these appliances shall not interfere with combustion air; draft hood clearance and relief; and accessibility for servicing.
Central-heating furnaces and low-pressure boilers shall be installed with clearances in accordance with the manufacturer's instructions.
Central-heating furnaces and low-pressure boilers 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 G2409.2 and such reduction is allowed by the manufacturer's instructions.
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.
Gas piping shall not be used as a grounding electrode.
Electrical connections between appliances and the building wiring, including the grounding of the appliances, shall conform to Chapters 34 through 43.
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 an appliance that is connected to the equipment grounding conductor of the circuit that supplies that appliance.
This section applies to corrugated stainless steel tubing (CSST) that is not listed with an arcresistant jacket or coating system in accordance with ANSI LC1/CSA 6.26. CSST gas piping systems and piping systems containing one or more segments of CSST shall be electrically continuous and bonded to the electrical service grounding electrode system or, where provided, the lightning protection grounding electrode system.
The bonding jumper shall be not smaller than 6 AWG copper wire or equivalent.
The length of the bonding jumper between the connection to a gas piping system and the connection to a grounding electrode system shall not exceed 75 feet (22 860 mm). Any additional grounding electrodes installed to meet this requirement shall be bonded to the electrical service grounding electrode system or, where provided, the lightning protection grounding electrode system.
Bonding connections shall be in accordance with NFPA 70.
Devices used for making the bonding connections shall be listed for the application in accordance with UL 467.
This section applies to corrugated stainless steel tubing (CSST) that is listed with an arc-resistant jacket or coating system in accordance with ANSI LC1/CSA 6.26. The CSST shall be electrically continuous and bonded to an effective ground fault current path. Where any CSST component of a piping system does not have an arc-resistant jacket or coating system, the bonding requirements of Section G2411.2 shall apply. Arc-resistantjacketed CSST shall be considered to be bonded where it is connected to an appliance that is connected to the appliance grounding conductor of the circuit that supplies that appliance.
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.
Utility service piping located within buildings shall be installed in accordance with the structural safety and fire protection provisions of this code.
The storage system for liquefied petroleum gas shall be designed and installed in accordance with the International Fire Code and NFPA 58.
In modifying or adding to existing piping systems, sizes shall be maintained in accordance with this chapter.
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.
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.
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.
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 G2413.
Piping, tubing and fittings shall be manufactured to the applicable referenced standards, specifications and performance criteria listed in Section G2414 and shall be identified in accordance with Section G2412.9.
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.
The volumetric flow rate of gas to be provided shall be the sum of the maximum input of the appliances served.
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.
The volumetric flow rate of gas to be provided shall be adjusted for altitude where the installation is above 2,000 feet (610 m) in elevation.
Gas piping shall be sized in accordance with one of the following:
- Pipe sizing tables or sizing equations in accordance with Section G2413.4 or G2413.5, as applicable.
- The sizing tables included in a listed piping system's manufacturer's installation instructions.
- Other approved engineering methods.
This section applies to piping materials other than noncorrugated stainless steel tubing. Where Tables G2413.4(1) through G2413.4(21) are used to size piping or tubing, the pipe length shall be determined in accordance with Section G2413.4.1, G2413.4.2 or G2413.4.3.
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 G2413.4.1, G2413.4.2 or G2413.4.3.
- Low-pressure gas equation [Less than 11/2 pounds per square inch (psi) (10.3 kPa)]:
(Equation 24-3) - High-pressure gas equation [11/2 psi (10.3 kPa) and above]:
(Equation 24-4)
where:
P1 = Upstream pressure, psia (P1 + 14.7).
P2 = Downstream pressure, psia (P2 + 14.7).
ΔH = Pressure drop, inch water column (27.7-inch water column = 1 psi).
TABLE G2413.4 (402.4)
Cr AND 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.
TABLE G2413.4(1) [402.4(2)]
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 (inches) | ||||||||||||||
| 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:
- NA means a flow of less than 10 cfh.
- Table entries have been rounded to three significant digits.
TABLE G2413.4(2) [402.4(5)]
SCHEDULE 40 METALLIC PIPE
| Gas | Natural |
| Inlet Pressure | 2.0 psi |
| Pressure Drop | 1.0 psi |
| Specific Gravity | 0.60 |
| PIPE SIZE (inches) | |||||||||
| 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: Table entries have been rounded to three significant digits.
TABLE G2413.4(3) [402.4(9)]
SEMIRIGID COPPER TUBING
| Gas | Natural |
| Inlet Pressure | Less than 2 psi |
| Pressure Drop | 0.5 in. w.c. |
| Specific Gravity | 0.60 |
| TUBE SIZE (inches) | ||||||||||
| 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 | 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:
TABLE G2413.4(4) [402.4(12)]
SEMIRIGID COPPER TUBING
| Gas | Natural |
| Inlet Pressure | 2.0 psi |
| Pressure Drop | 1.0 psi |
| Specific Gravity | 0.60 |
| TUBE SIZE (inches) | ||||||||||
| 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:
TABLE G2413.4(5) [402.4(15)]
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:
- Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends 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 or bends.
- 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.
- Table entries have been rounded to three significant digits.
TABLE G2413.4(6) [402.4(18)]
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:
- 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.
- CAUTION: Capacities shown in the table might exceed maximum capacity for a selected regulator. Consult with the regulator or tubing manufacturer for guidance.
- Table includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bends 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 or bends.
- 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.
- Table entries have been rounded to three significant digits.
TABLE G2413.4(7) [402.4(21)]
POLYETHYLENE PLASTIC PIPE
| Gas | Natural |
| Inlet Pressure | Less than 2 psi |
| Pressure Drop | 0.5 in. w.c. |
| Specific Gravity | 0.60 |
| PIPE SIZE (inches) | ||||||
| Nominal OD | 1/2 | 3/4 | 1 | 11/4 | 11/2 | 2 |
| Designation | SDR 9 | SDR 11 | SDR 11 | SDR 10 | SDR 11 | SDR 11 |
| 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 | |||||