The text of this chapter is extracted from the 2015 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.
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-gaspiping systems,
fuel-gasappliances 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.
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 the code and are defined in the Michigan electrical
code, R 408.30801 to R 408.30880, Michigan building code,
R 408.30401 to R 408.30547, International Fire Code and
International Fuel Gas Code listed in Chapter 44, Michigan
mechanical code, R 408.30901 to R 408.30998 or Michigan
plumbing code, R 408.30701 to R 408.30796, the terms shall
have the 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 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 raw material to produce light, heat, power, refrigeration or air conditioning.
APPROVED AGENCY. An established and recognized agency that is regularly engaged in conducting tests or furnishing inspection services, 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.
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 boileroutlet.
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 boileroutlet.
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.
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 labeledchimney composed of factory-made components, assembled in the field in accordance with manufacturer's instructions and the conditions of the listing.
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.
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.
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.
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.
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.
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 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.
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.
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 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 appliancelocation.
FURNACEPLENUM. 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 applianceto, 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.
IGNITION SOURCE. A flame spark or hot surface capable of igniting flammable vapors or fumes. Such sources include applianceburners, 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 press 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 which 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.
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 applianceis 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, when tested in accordance with ASTM E136, have at least 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 approvedbends that make two changes in direction bringing one section of the vent out of line, but into a line parallel with the other section.
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 (applianceregulator).
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.
Manual reset type. A valve that automatically opens a reliefvent at a predetermined temperature and that must be manually returned to the closed position.
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, 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 also "Vented room heater.")
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.
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.
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.
Snap-acting thermostat. A thermostat in which the thermostatic valve travels instantly from the closed to the open position, and vice versa.
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 approvedthird-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.
TRANSITION FITTINGS, PLASTIC TO STEEL. An adapter for joining plastic pipeto 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.
High-static pressure type. A self-contained, automatically controlled, vented appliancehaving integral means for circulation of air against 0.2 inch w.c. (50 Pa) or greater static pressure. Such applianceis equipped with provisions for attaching an outlet air duct and, where the applianceis 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 appliancedesigned for stationary installation and utilized to provide comfort heating. Such appliancesprovide 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.
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 approvedmeans.
Automatic gas shutoff. A valveused 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 valvein 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.
VENT. A pipeor 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.
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 reliefmechanism, a breathervent can also serve as a reliefvent.
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.
Category I. An appliancethat operates with a nonpositive vent static pressure and with a vent gas temperature that avoids excessive condensateproduction in the vent.
Category II. An appliancethat operates with a nonpositive vent static pressure and with a vent gas temperature that is capable of causing excessive condensateproduction in the vent.
Category IV. An appliancethat operates with a positive vent static pressure and with a vent gas temperature that is capable of causing excessive condensateproduction in the vent.
VENTED ROOM HEATER. A vented self-contained, freestanding, 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.
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 combustionthrough the front into the room being heated.
This section shall govern the
approval and installation of all equipment and appliancesthat
comprise parts of the installations regulated by this code in
accordance with Section G2401.
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.
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.
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
appliancesshall be provided with an auxiliary drain
pan where damage to any building component will occur as a
result of stoppage in the condensatedrainage 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 condensatedrainage system.
Condensate pumps
located in uninhabitable spaces, such as attics and crawl
spaces, shall be connected to the applianceor equipment
served such that when the pump fails, the applianceor 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 which 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 alterationsare
specifically considered in the design of the member by a registered
design professional.
Appliancesshall be located as
required by this section, specific requirements elsewhere in
this code and the conditions of the equipmentand 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 applianceis a direct-ventapplianceinstalled in
accordance with the conditions of the listing and the
manufacturer's instructions.
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.
The applianceis 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
approvedself-closing device. All combustion air shall
be taken directly from the outdoors in accordance with
Section G2407.6.
Appliancesinstalled 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.
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 opening s sized and located in accordance with Section G2407.5.3, are considered to be
part of the required volume.
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 appliancesin 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).
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.
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 (1,100 mm2/
kW) of total input rating of all appliancesin 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 applianceshall have clearancesof 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 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
applianceslocated in the enclosure and not less than the
sum of the areas of all vent connectors in the space.
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).
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
applianceslocated within the space.
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.
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 applianceso
that they are proven to be in the full open position prior to
main burner ignition and duringmain 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.
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-ventappliances shall be installed in accordance with the
appliancemanufacturer's instructions.
Equipmentand appliancesshall
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 equipmentor applianceor the
manufacturer's installation instructions, the conditions of the
listing and the manufacturer's installation instructions shall
apply.
Unlisted appliancesapproved 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 applianceshaving 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 appliancesthat are listed as flammable-vapor-ignition
resistant.
In residential garages where appliancesare installed in a
separate, enclosed space having access only from outside
of the garage, such appliancesshall 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.
The allowable clearance reduction shall be based on one of the methods specified in Table G2409.2 or shall utilize a reduced clearanceprotective assembly listed and labeledin accordance with UL 1618. Where required clearancesare 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 clearancesto combustibles for listed and labeledappliances and equipmentshall be in accordance with the requirements of this section, except that such clearancesshall not be reduced where reduction is specifically prohibited by the terms of the applianceor equipment listing [see Figures G2409.2(1) through 2409.2(3)].
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)]
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 at least 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 an air gap of not less than 1 inch. 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 not less than 8 pounds per cubic foot and a melting point of not less than 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. The clearance between the appliance and the combustible surface shall not be reduced below that allowed in this table.
All 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.
NOTES: "A" equals the clearance without protection. "B" equals 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)] EXTENT OF PROTECTION NECESSARY TO REDUCE CLEARANCES FROM GAS EQUIPMENT OR VENT CONNECTORS 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
Supply
air ducts connecting to listed central heating furnaces
shall have the same minimum clearance to combustibles as
required for the furnace supply plenum for a distance of not
less than 3 feet (914 mm) from the supply plenum. Clearance
is not required beyond the 3-foot (914 mm) distance.
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.
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.
All table entries have been rounded to three significant digits.
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.
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 capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
NA means a flow of less than 10 cfh.
All table entries have been rounded to three significant digits.
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 capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
All table entries have been rounded to three significant digits.
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.
All table entries have been rounded to three significant digits.
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.
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.
All table entries have been rounded to three significant digits.
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.
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.
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.
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.
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.
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.
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 capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
All table entries have been rounded to three significant digits.
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 capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
NA means a flow of less than 10000 Btu/hr.
All table entries have been rounded to three significant digits.
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 capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
All table entries have been rounded to three significant digits.
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.
All table entries have been rounded to three significant digits.
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.
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.
All table entries have been rounded to three significant digits.
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.
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.
All table entries have been rounded to three significant digits.
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.
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.
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.
Supply
air ducts connecting to listed central heating furnaces
shall have the same minimum clearance to combustibles as
required for the furnace supply plenum for a distance of
not less than 3 feet (914 mm) from the supply plenum.
Clearance is not required beyond the 3-foot (914 mm) distance.
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.
Corrugated stainless steel tubing (CSST) gas piping systems shall be bonded to the electrical service grounding electrode system or where provided, lightening protection electrode system. The bonding jumper shall connect to a metallic pipe, pipe fitting, or CSST fitting between the point of delivery and the CSST utilizing a device listed for the application. The bonding jumper shall be not smaller than 6 AWG copper wire or equivalent, not longer than 75 feet and accessible. Gas piping systems that are bonded in accordance with this section shall be considered effectively bonded regardless of the amount of CSST in the system. Any additional grounding electrodes used shall be bonded to the electrical service grounding electrode system, or where provided, the lighting protection grounding electrode system.
Exception: CSST piping systems tested and listed by the manufacturer for installation without additional bonding when installed in accordance with the listing.
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.
Where an additional
applianceis 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.
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.
Where two or more
metersare 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 meterinstallations shall be marked with an approved
permanent identification by the installer so that the piping
system supplied by each meteris readily identifiable.
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
G2413.
Piping, tubing and fittings shall comply with the applicable
referenced standards, specifications and performance criteria
of this code and shall be identified in accordance with Section
G2412.9. Piping, tubing and fittings shall either be tested by
an approved third-party testing agency or certified by an
approvedthird-party certification agency.
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.
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.
Pipe size of each section of the longest piperun
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.
The pipesize of each section of branchpiping not previously
sized shall be determined using the length of
piping from the point of delivery to the most remote
outletin each branch and the load of the section.
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
pipesize 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.
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
applianceis greater than or equal to the minimum pressure
required by the appliance.
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:
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.
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.
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
code official.
Copper
tubing shall comply with Standard Type K or L of
ASTM B88 or ASTM B280.
Copper and copper alloy 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).
Polyethylene
plastic pipe, tubing and fittings used to supply fuel gas
shall conform to ASTM D2513. Such pipe shall be marked
"Gas" and "ASTM D2513."
Plastic pipe, tubing and fittings, other than polyethylene,
shall be identified and conform to the 2008 edition of ASTM
D2513. Such pipe shall be marked "Gas" and "ASTM D2513."
Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride
(CPVC) plastic pipe, tubing and fittings shall not be used
to supply fuel gas.
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.
Service head adapters and field-assembled anodeless
risers incorporating service head adapters shall be
recommended by the manufacturer for the gas used,
and shall be designed and certified to meet the
requirements of Category I of ASTM D2513, and
U.S. Department of Transportation, Code of Federal
Regulations, Title 49, Part 192.281(e). The manufacturer
shall provide the user with qualified installation
instructions as prescribed by the U.S. Department of
Transportation, Code of Federal Regulations, Title
49, Part 192.283(b).
Plastic pipe
and fittings used to connect regulatorvents to remote vent
terminations shall be of PVC conforming to ANSI/UL
651. PVC vent piping shall not be installed indoors.
Pipe, 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 pipeor tubingor fittings shall not be repaired.
Defective pipe, tubing or fittings shall be replaced. (See Section
G2417.1.2.)
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.
Pipe with threads
that are stripped, chipped, corroded or otherwise damaged
shall not be used. Where a weld opens during the operation
of cutting or threading, that portion of the pipe shall
not be used.
Thread
joint compounds 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.
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 caused by 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.
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.
Tubingjoints 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.
Flared joints shall
be used only in systems constructed from nonferrous pipe
and tubingwhere 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.
Metallic fittings,
shall comply with the following:
Fittings used with steel or wrought-iron pipe shall be
steel, copper alloy, malleable iron or cast iron.
Fittings used with copper or copper alloy pipe shall
be copper or copper alloy.
Cast-iron bushings shall be prohibited.
Special fittings. Fittings such as couplings, proprietary-type joints, saddle tees, gland-type compression
fittings, and flared, flareless and compression-type
tubingfittings shall be: used within the fitting manufacturer's
pressure-temperature recommendations;
used within the service conditions anticipated with
respect to vibration, fatigue, thermal expansion and
contraction; and shall be approved.
Where pipe fittings are drilled and tapped in the
field, the operation shall be in accordance with all of
the following:
The operation shall be performed on systems
having operating pressures of 5 psi (34.5 kPa)
or less.
The operation shall be performed by the gas
supplier or the gas supplier's designated representative.
The drilling and tapping operation shall be performed
in accordance with written procedures
prepared by the gas supplier.
The fittings shall be located outdoors.
The tapped fitting assembly shall be inspected
and proven to be free of leakage.
Plastic
pipe, tubing and fittings shall be joined in accordance with
the manufacturers' instructions. Such joints shall comply
with the following:
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.
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 D2513."
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 pipeor tubingand 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.
Plastic piping joints and fittings for use in liquefied
petroleum gas piping systems shall be in accordance
with NFPA 58.
Materials used
shall be installed in strict accordance with the standards under
which the materials are accepted and approved. In the
absence of such installation procedures, the manufacturer's
instructions shall be followed. Where the requirements of referenced
standards or manufacturer's instructions do not conform
to minimum provisions of this code, the provisions of
this code shall apply.
CSST piping systems shall be
installed in accordance with the terms of their approval, the
conditions of listing, the manufacturer's instructions and this
code.
Piping shall not be
installed in or through a ducted supply, return or exhaust, or a
clothes chute, chimneyor 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.
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.
Where piping will be concealed within light-frame construction
assemblies, the piping shall be protected against penetration
by fasteners in accordance with Sections G2415.7.1
through G2415.7.3.
Exception: Black steel piping and galvanized steel piping
shall not be required to be protected.
Where piping is installed through holes or notches
in framing members and the piping is located less than 11/2
inches (38 mm) from the framing member face to which
wall, ceiling or floor membranes will be attached, the pipe
shall be protected by shield plates that cover the width of
the pipe and the framing member and that extend not less
than 4 inches (51 mm) to each side of the framing member.
Where the framing member that the piping passes through
is a bottom plate, bottom track, top plate or top track, the
shield plates shall cover the framing member and extend
not less than 4 inches (51 mm) above the bottom framing
member and not less than 4 inches (51 mm) below the top
framing member.
Where the piping is located within a framing member and
is less than 11/2 inches (38 mm) from the framing member
face to which wall, ceiling or floor membranes will be
attached, the piping shall be protected by shield plates that
cover the width and length of the piping. Where the piping
is located outside of a framing member and is located less
than 11/2 inches (38 mm) from the nearest edge of the face
of the framing member to which the membrane will be
attached, the piping shall be protected by shield plates that
cover the width and length of the piping.
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 approvedmanner. 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 G2415.6.1 or G2415.6.2.
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 pipeemerges
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 the building, shall be
vented above grade to the outdoors and shall be installed to
prevent the entrance of water and insects.
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.
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.
Metallic piping and metallic
tubingthat conveys fuel gas from an LP-gas storage container
shall be provided with an approveddielectric 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 above ground outdoors.
Metallic
pipe or tubingexposed to corrosive action, such as soil condition
or moisture, shall be protected in an approvedmanner.
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.
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.
Pipe protective coatings and wrappings shall be
approvedfor the application and shall be factory applied.
Exception: Where installed in accordance with the
manufacturer's 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.
Individual lines to outdoor lights, grills or other appliances
shall be installed not less than 8 inches (203 mm)
below finished grade, provided that such installation is
approvedand is installed in locations not susceptible to
physical damage.
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 approvedconduit material
designed to withstand the superimposed loads. The conduit
shall be protected from corrosion in accordance with
Section G2415.11 and shall be installed in accordance with
Section G2415.14.1 or G2415.14.2.
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 pipingshall 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.
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.
Gas outlets that do not
connect to appliancesshall be capped gas tight.
Exception:Listed and labeledflush-mounted-type quick-disconnect
devices and listed and labeled gas convenience
outlets shall be installed in accordance with the manufacturer's
instructions.
The unthreaded portion
of piping outlets shall extend not less than 1 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 outletfitting or piping shall be securely supported. Outletsshall not be placed
behind doors. Outletsshall be located in the room or space
where the applianceis installed.
Exception: Listed and labeledflush-mounted-type quick-disconnect
devices and listed and labeled gas convenience
outlets shall be installed in accordance with the manufacturer's
instructions.
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:
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 instructions.
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.
Plastic pipe shall be permitted under outdoor
patio, walkway and driveway slabs provided that
the burial depth complies with Section G2415.10.
Connections outdoors
and underground between metallic and plastic piping
shall be made only with transition fittings conforming
to ASTM D2513 Category I or ASTM F1973.
A yellow insulated copper
tracer wire or other approvedconductor 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.
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 G2417.
Prior to acceptance and initial
operation, all piping installations shall be visually inspected
and pressure tested to determine that the materials, design,
fabrication and installation practices comply with the requirements
of this code.
In the event
repairs or additions are made after thepressure 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 approvedleak-detecting methods.
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
approvedleak-detecting methods.
A piping system
shall be permitted to be tested as a complete unit or in sections. Under no circumstances shall a valvein a line be
used as a bulkhead between gas in one section of the piping
system and test medium in an adjacent section, except
where a double block and bleed valve system is installed.
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.
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.
Appliancesand equipmentthat are not to be included
in the test shall be either disconnected from the piping or
isolated by blanks, blind flanges or caps.
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.
The test pressure to
be used shall be not less than 11/2 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.
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.
During the
process of turning gas on into a system of newgas piping,
the entire system shall be inspected to determine that there
are no open fittings or ends and that all valvesat unused
outlets are closed and plugged or capped.
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.
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 G2417.7.1.3. Where gas piping meeting the criteria of Table G2417.7.1.1 is removed from service, the residual fuel gas in the piping shall be displaced with an inert gas.
Where
gas piping containing air and meeting the criteria of
Table G2417.7.1.1 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 G2417.7.1.3.
The open end of a piping system being pressure vented or purged shall discharge directly to an outdoor location. Purging operations shall comply will all of the following requirements:
The point of discharge shall be controlled with a shutoff valve.
The point of discharge shall be located not less than 10 feet (3048 mm) from sources of ignition, not less than 10 feet (3048 mm) from building openings and not less than 25 feet (7620 mm) from mechanical air intake openings.
During discharge, the open point of discharge shall be continuously attended and monitored with a combustible gas indicator that complies with Section G2417.7.1.4.
Purging operations introducing fuel gas shall be stopped when 90 percent fuel gas by volume is detected within the pipe.
Persons not involved in the purging operations shall be evacuated from all areas within 10 feet (3048 mm) of the point of discharge.
Combustible gas indicators shall be listed and shall be
calibrated in accordance with the manufacturer's
instructions. Combustible gas indicators shall numerically
display a volume scale from zero percent to 100
percent in 1 percent or smaller increments.
The piping
system shall be purged in accordance with one or
more of the following:
The piping shall be purged with fuel gas and shall
discharge to the outdoors.
The piping shall be purged with fuel gas and shall
discharge to the indoors or outdoors through an
applianceburner not located in a combustion
chamber. Such burner shall be provided with a
continuous source of ignition.
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.
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 Section G2417.7.2.2. Purging shall be
stopped when fuel gas is detected.
The piping shall be purged by the gas supplier in
accordance with written procedures.
Combustible gas detectors shall be listed and shall be
calibrated or tested in accordance with the manufacturer's
instructions. Combustible gas detectors shall be
capable of indicating the presence of fuel gas.
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 appliancesand 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 G2424. 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 equipmentshall be
designed and installed so that they will not be disengaged by
movement of the supported piping.
Where wet gas exists, a drip shall be
provided at any point in the line of pipe where condensate
could collect. A dripshall also be provided at the outlet of the
meterand shall be installed so as to constitute a trap wherein
an accumulation of condensatewill shut off the flow of gas
before the condensatewill run back into the meter.
Where a sediment trap is
not incorporated as part of the appliance, a sediment trap shall
be installed downstream of the appliance shutoffvalve 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 bottommost opening of the
tee as illustrated in Figure G2419.4 or other device approved
as an effective sediment trap. Illuminating appliances, ranges,
clothes dryers, decorative vented appliances for installation in
vented fireplaces, gas fireplaces and outdoor grills need not
be so equipped. FIGURE G2419.4 (408.4)
METHOD OF INSTALLING A TEE FITTING SEDIMENT TRAP
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 G2420.1.1.
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 appliancemanufacturer's
instructions.
Where the appliance shutoffvalve is installed at a manifold, such shutoff valve shall be located within 50 feet (15240 mm) of the applianceserved and shall be readily accessible and permanently identified. The piping from the manifold to within 6 feet (1829 mm) of the applianceshall be designed, sized and installed in accordance with Sections G2412 through G2419.
The MP regulatorshall be approvedand shall be suitable for the inlet and outlet gas pressures for the application.
The MP regulatorshall maintain a reduced outlet pressure under lock-up (no-flow) conditions.
The capacity of the MP regulator, determined by published ratings of its manufacturer, shall be adequate to supply the appliancesserved.
The MP pressure regulator shall be provided with access. Where located indoors, the regulatorshall be vented to the outdoors or shall be equipped with a leak-limiting device, in either case complying with Section G2421.3.
A tee fitting with one opening capped or plugged shall be installed between the MP regulatorand 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.
A tee fitting with one opening capped or plugged shall be installed not less than 10 pipediameters downstream of the MP regulatoroutlet. Such tee fitting shall be positioned to allow connection of a pressure-measuring instrument.
Where connected to rigid piping, a union shall be installed within 1 foot (304 mm) of either side of the MP regulator.
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
approvedvent-limiting device installed in accordance with
the manufacturer's instructions.
Where automaticexcess flow valves are installed, they shall be listed for the
application and shall be sized and installed in accordance
with the manufacturer's instructions.
Where
fuel gas is used with oxygen in any hot work operation, a
listed protective device that serves as a combination flashback
arrestor and backflow check valve shall be installed at
an approvedlocation on both the fuel gas and oxygen supply
lines. Where the pressure of the piped fuel gas supply is
insufficient to ensure such safe operation, approvedequipment
shall be installed between the gas meter and the appliance
that increases pressure to the level required for such safe
operation.
Corrugated stainless steel tubing(CSST) where
installed in accordance with the manufacturer's instructions.
Listed and labeledappliance connectors in compliance
with ANSI Z21.24 and installed in accordance with the
manufacturer's instructions and located entirely in the
same room as the appliance.
Listed and labeledoutdoor appliance connectors in
compliance with ANSI Z21.75/CSA 6.27 and installed
in accordance with the manufacturer's instructions.
Listed outdoor gas hose connectors in compliance with
ANSI Z21.54 used to connect portable outdoor appliances.
The gas hose connection shall be made only in
the outdoor area where the applianceis used, and shall
be to the gas piping supply at an appliance shutoffvalve, a listed quick-disconnect device or listed gas
convenience outlet.
Connectors
shall have an overall length not to exceed 6 feet
(1829 mm). Measurement shall be made along the centerline
of the connector. Only one connector shall be
used for each appliance.
Connectors shall not be concealed
within, or extended through, walls, floors, partitions,
ceilings or appliancehousings.
Exceptions:
Connectors constructed of materials allowed
forpiping systems in accordance with Section
G2414 shall be permitted to pass through
walls, floors, partitions and ceilings where
installed in accordance with Section
G2420.5.2 or G2420.5.3.
Rigid steel pipe connectors shall be permitted
to extend through openings in appliancehousings.
Fireplaceinserts that are factory equipped
with grommets, sleeves or other means of protection
in accordance with the listing of the
appliance.
Semirigid tubingand listed connectors shall be
permitted to extend through an opening in an
appliancehousing, cabinet or casing where the
tubing or connector is protected against damage.
A union fitting shall be provided
for appliancesconnected by rigid metallic pipe.
Such unions shall be accessible and located within 6 feet
(1829 mm) of the appliance.
Where appliances
are equipped with casters or are otherwise subject to
periodic movement or relocation for purposes such as routine
cleaning and maintenance, such appliancesshall be
connected to the supply system piping by means of an
appliance connector listed as complying with ANSI
Z21.69 or by means of Item 1 of Section G2422.1. Such
flexible connectors shall be installed and protected against
physical damage in accordance with the manufacturer's
instructions.
Suspended low-intensity infrared tube heaters shall
be connected to the building piping system with a connector
listed for the application complying with ANSI Z21.24/CGA
6.10. The connector shall be installed as specified by the tube
heater manufacturer's instructions.
Piping shall be supported at intervals not exceeding the spacing specified in Table G2424.1. Spacing of supports for CSST shall be in accordance with the CSST manufacturer's instructions.
This section shall govern the installation,
maintenance, repair and approval of factory-built
chimneys, chimney liners, vents and connectors and the utilization
of masonry chimneys serving gas-fired appliances.
Where an appliance
equipped with a mechanical forced draftsystem creates a
positive pressure in the venting system, the venting system
shall be designed for positive pressure applications.
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.
An applianceshall not be connected to a flue
serving a factory-built fireplace unless the applianceis
specifically listed for such installation. The connection
shall be made in accordance with the appliance manufacturer's
installation instructions.
A connector shall extend from the applianceto the
flue serving amasonry 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.
Where the applianceslisted 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 appliancesare installed, one or more shall be provided with ventingsystems 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 applianceis 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.
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
thechimney flue.
Appliance
connections to a chimneyor 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.
Masonry chimneys
utilized to vent applian ces shall be located, constructed and
sized as specified in the manufacturer' s installation instructions
for the appliancesbeing vented and Section G2427.
The design, sizing and installation of vents for
Category II, III and IV appliancesshall be in accordance with
the appliancemanufacturer's instructions.
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 applianceor fireplace.
The flue liner, chimneyinner 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.
Masonry chimneyflues
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 chimneyinlet opening. The cleanout
shall be provided with a tight-fitting, noncombustible
cover.
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 chimneyswith reduced clearancesin accordance
with UL 1777. The chimneyclearanceshall be not less
than that permitted by the terms of the chimneyliner
listing and the manufacturer' s instructions.
Vents, except as provided in Section
G2427.7, 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 appliancesshall be tested in accordance
with UL 1738. Plastic vents for Category IVappliancesshall
not be required to be listed and labeledwhere such vents are
as specified by the appliancemanufacturer and are installed
in accordance with the appliancemanufacturer's instructions.
Connectors shall be
used to connect appliancesto the vertical chimney or vent,
except where the chimneyor vent is attached directly to the
appliance. Ventconnector size, material, construction and
installation shall be in accordance with Section G2427.
Where vents pass
through insulated assemblies, an insulation shield constructed
of steel having a minimum thickness of 0.0187 inch (0.4712
mm) (No. 26 gage) shall be installed to provide clearance
between the vent and the insulation material. The clearance
shall not be less than the clearanceto combustibles specified
by the ventmanufacturer'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 instructions.
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.
Appliance and equipmentvent terminals shall be located such that doors cannot
swing within 12 inches (305 mm) horizontally of the vent
terminal. Door stops or closures shall not be installed to
obtain this clearance.
Appliancesincorporating integral venting means shall be
installed in accordance with the manufacturer's instructions
and Section G2427.8, Items 1 and 2.
Appliances
required to be vented shall be connected to a venting
system designed and installed in accordance with the provisions
of Sections G2427.4 through G2427.16.
Mechanical
draftsystems shall comply with the following:
Mechanical draft systems shall be listed and shall be
installed in accordance with the manufacturer's
instructions for both the appliance and the mechanical
draft system.
Forced draftsystems 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.
Where a mechanical draft system is employed, provisions
shall be made to prevent the flow of gas to
the mainburnerswhen the draftsystem is not performing
so as to satisfy the operating requirements
of the appliancefor safe performance.
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
G2427.8, Items 1 and 2.
Where a venting system passes through an above-ceiling
air-handling space or other nonducted portion of an airhandling
system, the venting system shall conform to one
of the following requirements:
The venting system shall be installed such that fittings
and joints between sections are not installed in
the above-ceiling space.
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.
Where plastic piping
is used to vent an appliance, the appliance shall be listed
for use with such venting materials and the appliance manufacturer's
installation instructions shall identify the specific
plastic piping material.
Plastic pipeand fittings used to ventappliancesshall be
installed in accordance with the appliancemanufacturer's
instructions. Where a primer is required, it shall
be of a contrasting color.
Factory-built
chimneysshall be installed in accordance with the
manufacturer's instructions. Factory-built chimneysused
to ventappliancesthat operate at a positive vent pressure
shall be listed for such application.
Masonry chimneys
shall be built and installed in accordance with NFP A
211 and shall be lined with approvedclayflue lining, a
listed chimney lining system or other approvedmaterial
that will resist corrosion, erosion, softening or cracking
from vent gases at temperatures up to 1,800°F (982°C).
Exception: Masonry chimneyflues serving listed gas
applianceswith draft hoods, Category Iappliances 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 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 chimneyliner is for appliancesthat burn
gas only. Do not connect to solid or liquid fuel-burning
appliances or incinerators."
Chimneys for
residential-type or low-heat appliancesshall extend not
less than 3 feet (914 mm) above the highest point where
they pass through a roof of a building and not less than 2
feet (610 mm) higher than any portion of a building within
a horizontal distance of 10 feet (3048 mm). Chimneysfor
medium-heat appliancesshall extend not less than 10 feet
(3048 mm) higher than any portion of any building within
25 feet (7620 mm). Chimneysshall extend not less than 5
feet (1524 mm) above the highest connected appliancedraft hoodoutlet or flue collar. Decorative shrouds shall
not be installed at the termination of factory-built chimneys
except where such shrouds are listed and labeledfor
use with the specific factory-built chimneysystem and are
installed in accordance with the manufacturer's instructions.
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 ventingsolid or liquid fuel-burning appliances or fireplaces.
Chimneys shall be lined in accordance with NFPA 211.
Exception: Where an existing chimney complies with Sections G2427.5.5 through G2427.5.5.3 and its sizing is in accordance with Section G2427.5.4, its continued use shall be allowed where the appliance vented by such chimney is replaced by an appliance of similar type, input rating and efficiency.
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 orchimney to conform
to NFPA 211 and it shall be suitable for theappliances
to be vented.
Where onechimney 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.
A combination gas- and
solid fuel-burningappliance shall be permitted to be
connected to a single chimney flue where equipped
with a manual reset device to shut off gas to themainburnerin the event of sustained backdraft or flue gas spillage. The chimney flue shall be sized to properly
vent the appliance.
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.
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.
Where a chimney that formerly carried flue products from liquid or solid fuel-burning appliances is used with an appliance using fuelgas, 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.
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.
A gas vent shall terminate in accordance with one of the following:
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 G2427.6.3.
Gas vents that are over 12 inches (305 mm) in size or are located less than 8 feet (2438 mm) from avertical 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.
For SI: 1 foot= 304.8 mm.FIGURE G2427.6.3 (503.6.4) TERMINATION LOCATIONS FOR GAS VENTS WITH LISTED CAPS 12 INCHES OR LESS IN SIZE AT LEAST 8 FEET FROM A VERTICAL WALL
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 instructions.
A Type B or L gas vent shall terminate at least 5 feet (1524 mm) in vertical height above the highest connected appliancedraft hood or flue collar. A Type B-W gas vent shall terminate not less than 12 feet (3658 mm) in vertical height above the bottom of the wall furnace.
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 G2427.2.1 and G2427.3.3.
Type B and L
vents sized in accordance with Item 2 or 3 of Section
G2427.6.8.1 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.
The sizing of gas vents for Category II, III
and IV appliances shall be in accordance with the appliance
manufacturer's instructions. The sizing of plastic
pipe that is specified by the appliance manufacturer as a
venting material for Category II, III and IV appliances,
shall be in accordance with the manufacturer's instructions.
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 code 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."
Screws,
rivets and other fasteners shall not penetrate the inner wall
of double-wall gas vents, except at the transition from an
appliancedraft hoodoutlet, aflue collar or a single-wall
metal connector to a double-wall vent.
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.
Uninsulated single-wall metal pipe shall not be used outdoors for ventingappliances in regions where the 99-percent winter design temperature is below 32°F (0°C).
Single-wall metal pipe
shall terminate at least 5 feet (1524 mm) in vertical height
above the highest connected appliancedraft hoodoutlet 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). Anapprovedcap or roof
assembly shall be attached to the terminus of a single-wall
metal pipe.
Single-wall
metal pipe shall be used only for runs directly from the
space in which theappliance is located through the roof or
exterior wall to the outdoor atmosphere.
(Equation 24-1)
(Equation 24-2)
(Equation 24-3)
(Equation 24-4)
