The regulations of this chapter shall govern the installation of fuel gas piping in or in connection with a building, structure or within the property lines of premises up to 5 pounds-force per square inch (psi) (34 kPa) for natural gas and 10 psi (69 kPa) for undiluted propane, other than service pipe. Fuel oil piping systems shall be installed in accordance with NFPA 31.
Coverage of piping systems shall extend from the point of delivery to the appliance connections. For other than undiluted liquefied petroleum gas (LP-Gas) systems, the point of delivery shall be the outlet of the service meter assembly or the outlet of the service regulator or service shutoff valve where no meter is provided. For undiluted LP-Gas systems, the point of delivery shall be considered to be the outlet of the final pressure regulator, exclusive of line gas regulators where no meter is installed. Where a meter is installed, the point of delivery shall be the outlet of the meter.
Requirements for piping systems shall include design, materials, components, fabrication, assembly, installation, testing, inspection, operation, and maintenance.
This code shall not apply to the following items (reference standards for some of which appear in Chapter 17):
Portable LP-Gas appliances and equipment of all types that are not connected to a fixed fuel piping system.
Installation of appliances such as brooders, dehydrators, dryers, and irrigation equipment used for agricultural purposes.
Raw material (feedstock) applications except for piping to special atmosphere generators.
Oxygen-fuel gas cutting and welding systems.
Industrial gas applications using such gases as acetylene and acetylenic compounds, hydrogen, ammonia, carbon monoxide, oxygen, and nitrogen.
Petroleum refineries, pipeline compressor or pumping stations, loading terminals, compounding plants, refinery tank farms, and natural gas processing plants.
Large integrated chemical plants or portions of such plants where flammable or combustible liquids or gases are produced by chemical reactions or used in chemical reactions.
LP-Gas installations at utility gas plants.
Liquefied natural gas (LNG) installations.
Fuel gas piping in electric utility power plants.
Proprietary items of equipment, apparatus, or instruments such as gas-generating sets, compressors, and calorimeters.
LP-Gas equipment for vaporization, gas mixing, and gas manufacturing.
LP-Gas piping for buildings under construction or renovations that is not to become part of the permanent building piping system—that is, temporary fixed piping for building heat.
Installation of LP-Gas systems for railroad switch heating.
Installation of LP-Gas and compressed natural gas (CNG) systems on vehicles.
Gas piping, meters, gas-pressure regulators, and other appurtenances used by the serving gas supplier in distribution of gas, other than undiluted LP-Gas.
Building design and construction, except as specified herein.
Fuel gas systems on recreational vehicles manufactured in accordance with NFPA 1192.
Fuel gas systems using hydrogen as a fuel.
Construction of appliances.
Upon completion of the installation, alteration, or repair of gas piping, and prior to the use thereof, the Authority Having Jurisdiction shall be notified that such gas piping is ready for inspection.
Excavations required for the installation of underground piping shall be kept open until the piping has been inspected and approved. Where such piping is covered or concealed before such approval, it shall be exposed upon the direction of the Authority Having Jurisdiction.
The Authority Having Jurisdiction shall make the following inspections and either shall approve that portion of the work as completed or shall notify the permit holder wherein the same fails to be in accordance with this code.
This inspection shall be made after gas piping authorized by the permit has been installed and before such piping has been covered or concealed or fixture or appliance has been attached thereto. This inspection shall include a determination that the gas piping size, material, and installation meet the requirements of this code.
This inspection shall be made after piping authorized by the permit has been installed, and after portions, thereof that are to be covered or concealed are so concealed, and before fixture, appliance, or shutoff valve has been attached thereto. This inspection shall comply with Section 1213.1. Test gauges used in conducting tests shall be in accordance with Section 318.0.
In cases where the work authorized by the permit consists of a minor installation of additional piping to piping already connected to a gas meter, the preceding inspections shall be permitted to be waived at the discretion of the Authority Having Jurisdiction. In this event, the Authority Having Jurisdiction shall make such inspection as deemed advisable to be assured that the work has been performed in accordance with the intent of this code.
Whereupon final piping inspection, the installation is found to be in accordance with the provisions of this code, a certificate of inspection shall be permitted to be issued by the Authority Having Jurisdiction.
A copy of the certificate of such final piping inspection shall be issued to the serving gas supplier supplying gas to the premises.
It shall be unlawful for a serving gas supplier, or person is furnishing gas, to turn on or cause to be turned on, a fuel gas or a gas meter or meters, until such certificate of final inspection, as herein provided, has been issued.
It shall be unlawful for a person, firm, or corporation, excepting an authorized agent or employee of a person, firm, or corporation engaged in the business of furnishing or supplying gas and whose service pipes supply or connect with the particular premises, to turn on or reconnect gas service in or on a premises where and when gas service is, at the time, not being rendered.
It shall be unlawful to turn on or connect gas in or on the premises unless outlets are securely connected to gas appliances or capped or plugged with screw joint fittings.
The Authority Having Jurisdiction or the serving gas supplier is hereby authorized to disconnect gas piping or appliance or both that shall be found not to be in accordance with the requirements of this code or that are found defective and in such condition as to endanger life or property.
Where such disconnection has been made, a notice shall be attached to such gas piping or appliance or both that shall state the same has been disconnected, together with the reasons thereof.
It shall be unlawful to remove or disconnect gas piping or gas appliance without capping or plugging with a screw joint fitting, the outlet from which said pipe or appliance was removed. Outlets to which gas appliances are not connected shall be left capped and gastight on a piping system that has been installed, altered, or repaired.
Exception: Where an approved listed quick-disconnect device is used.
Where temporary use of gas is desired, and the Authority Having Jurisdiction deems the use necessary, a permit shall be permitted to be issued for such use for a period not to exceed that designated by the Authority Having Jurisdiction, provided that such gas piping system otherwise is in accordance with the requirements of this code regarding material, sizing, and safety.
Where required by the Authority Having Jurisdiction, a piping sketch or plan shall be prepared before proceeding with the installation. The plan shall show the proposed location of piping, the size of different branches, the various load demands, and the location of the point of delivery. [NFPA 54:5.1.1]
When additional appliances are being connected to a gas piping system, the existing piping shall be checked to determine whether it has adequate capacity. If inadequate, the existing system shall be enlarged as required, or separate gas piping of adequate capacity shall be provided.
The location of the point of delivery shall be acceptable to the serving gas supplier.
Where two or more meters, or two or more service regulators where meters are not provided, are located on the same premises and supply separate users, the gas piping systems shall not be interconnected on the outlet side of the meters or service regulators.
Where a supplementary gas for standby use is connected downstream from a meter or a service regulator where a meter is not provided, equipment to prevent backflow shall be installed. A three-way valve installed to admit the standby supply, and at the same time shut off the regular supply, shall be permitted to be used for this purpose.
Gas piping systems shall be of such size and so installed as to provide a supply 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 inputs of the appliances served. The volumetric flow rate of gas to be provided shall be adjusted for altitude where the installation is above 2000 feet. Where the input rating is not indicated, the gas supplier, appliance manufacturer, or a qualified agency shall be contacted, or the rating from Table 1208.4.1 shall be used for estimating the volumetric flow rate of gas to be supplied.
Gas piping shall be sized in accordance with one of the following:
Pipe sizing tables or sizing equations in this chapter.
Other approved engineering methods acceptable to the Authority Having Jurisdiction.
Sizing tables included in a listed piping system manufacturer's installation instructions.
The design pressure loss in any piping system under maximum probable flow conditions, from the point of delivery to the inlet connection of the appliance, shall be such that the supply pressure at the appliance is greater than or equal to the minimum pressure required by the appliance.
The maximum design operating pressure for piping systems located inside buildings shall not exceed 5 psi (34 kPa) unless one or more of the following conditions are met:
The piping system is welded.
The piping is located in a ventilated chase or otherwise enclosed for protection against accidental gas accumulation.
The piping is located inside buildings or separate areas of buildings used exclusively for one of the following:
Industrial processing or heating
Research
Warehousing
Boiler or mechanical rooms
The piping is a temporary installation for buildings under construction.
The piping serves appliances or equipment used for agricultural purposes.
The piping system is an LP-Gas piping system with a design operating pressure greater than 20 psi (138 kPa) and complies with NFPA 58.
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 to prevent LP-Gas vapor from condensing back into a liquid.
Materials used for piping systems shall either comply with the requirements of this chapter or be acceptable to the Authority Having Jurisdiction.
Pipe, fittings, valves, or other materials shall not be used again unless they are free of foreign materials and have been ascertained to be approved for the service intended.
Material not covered by the standards specifications listed herein shall meet the following criteria:
Be investigated and tested to determine that it is safe and suitable for the proposed service.
Be recommended for that service by the manufacturer.
Be acceptable to the Authority Having Jurisdiction.
Cast-iron pipe shall not be used.
Steel and wrought-iron pipe shall be at least of standard weight (Schedule 40) and shall comply with one of the following standards:
ASME B36.10
ASTMA53
ASTMA106
Copper and copper alloy pipe shall not be used if the gas contains more than an average of 0.3 grains of hydrogen sulfide per 100 standard cubic feet (scf) of gas (0.7 mg/100 L).
Threaded copper, copper alloy, or aluminum alloy pipe shall not be used with gases corrosive to such material.
Aluminum alloy pipe shall comply with ASTM B241 (except that the use of alloy 5456 is prohibited) and shall be marked at each end of each length indicating compliance. Aluminum alloy pipe shall be coated to protect against external corrosion where it is in contact with masonry, plaster, insulation or is subject to repeated wettings by such liquids as water, detergents, or sewage.
Aluminum alloy pipe shall not be used in exterior locations or underground.
Seamless copper, aluminum alloy, or steel tubing shall not be used with gases corrosive to such material.
Steel tubing shall comply with ASTM A254.
Copper and copper alloy tubing shall not be used where the gas contains more than an average of 0.3 grains of hydrogen sulfide per 100 scf of gas (0.7 mg/100 L). Copper tubing shall comply with standard Type K or L of ASTM B88 or ASTM B280.
Aluminum alloy tubing shall comply with ASTM B210 or ASTM B241. Aluminum alloy tubing shall be coated to protect against external corrosion where it is in contact with masonry, plaster, insulation, or is subject to repeated wettings by such liquids as water, detergent, or sewage. Aluminum alloy tubing shall not be used in exterior locations or underground.
Corrugated stainless steel tubing shall be listed in accordance with CSA LC-1.
Polyethylene plastic pipe, tubing, and fittings used to supply fuel gas shall conform to ASTM D2513. Pipe to be used 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.
Plastic pipe and fittings used to connect regulator vents to remote vent terminations shall be PVC conforming to UL 651(Schedule 40 and 80). PVC vent piping shall not be installed indoors.
Anodeless risers shall comply with the following:
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 design-certified to be in accordance with the requirements of Category I of ASTM D2513. The manufacturer shall provide the user qualified installation instructions.
The use of plastic pipe, tubing, and fittings in undiluted LP-Gas piping systems shall be in accordance with NFPA 58.
Gas 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 pipe, tubing, and fittings shall not be repaired. Defective pipe, tubing, and fittings shall be replaced.
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.
Metallic pipe and fitting threads shall be taper pipe threads and shall comply with ASME Bl.20.1.
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.
Field threading of metallic pipe shall be in accordance with Table 1208.6.10.2.
Thread joint compounds shall be resistant to the action of LP-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 and temperature conditions and shall be selected giving consideration to joint tightness and mechanical strength under the service conditions. The joint shall be able to sustain the maximum end force due to the internal pressure and any additional forces due to temperature expansion or contraction, vibration, fatigue, or the weight of the pipe and its contents.
Pipe joints shall be threaded, flanged, brazed, welded, or press-connect fittings that comply with CSA LC-4. Where nonferrous pipe is brazed, the brazing materials shall have a melting point in excess of 1000°F (538°C). Brazing alloys shall not contain more than 0.05 percent phosphorus.
Tubing joints shall be made with approved gas tubing fittings, be brazed with a material having a melting point in excess of 1000°F (538°C), or made by press-connect fittings that comply with CSA 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 tubing where experience or tests have demonstrated that the joint is approved for the conditions and where provisions are made in the design to prevent separation of the joints.
Metallic pipe fittings shall comply with the following:
Threaded fittings in sizes larger than 4 inches (100 mm) shall not be used unless approved by the Authority Having Jurisdiction.
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.
Fittings used with aluminum alloy pipe shall be of aluminum alloy.
Cast-iron fittings shall comply with the following:
Flanges shall be permitted.
Bushings shall not be used.
Fittings shall not be used in systems containing flammable gas-air mixtures.
Fittings in sizes 4 inches (100 mm) and larger shall not be used indoors unless approved by the Authority Having Jurisdiction.
Fittings in sizes 6 inches (150 mm) and larger shall not be used unless approved by the Authority Having Jurisdiction.
Aluminum alloy fitting threads shall not form the joint seal.
Zinc-aluminum alloy fittings shall not be used in systems containing flammable gas-air mixtures.
Special fittings such as couplings; proprietary-type joints; saddle tees; gland-type compression fittings; and flared, flareless, or compression-type tubing fittings shall be as follows:
Used within the fitting manufacturer's pressure-temperature recommendations.
Used within the service conditions anticipated with respect to vibration, fatigue, thermal expansion, or contraction.
Installed or braced to prevent separation of the joint by gas pressure or external physical damage.
Approved by the Authority Having Jurisdiction.
Plastic pipe, tubing, and fittings shall be installed in accordance with the manufacturer's installation instructions. Section 1208.6.12.1 through Section 1208.6.12.4 shall be observed where making such joints.
The joint shall be designed and installed so that the longitudinal pull-out resistance of the joint 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 gastight joints 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 pipe or tubing and shall extend not less than the outside end of the compression fitting where installed. The stiffener shall be free of rough or sharp edges and shall not be a forced fit in the plastic. Split tubular stiffeners shall not be used.
Plastic piping joints and fittings for use in LP-Gas piping systems shall be in accordance with NFPA 58.
Flanges shall comply with Section 1208.6.13.1 through Section 1208.6.13.7.
Cast iron flanges shall be in accordance with ASME B16.1.
Steel flanges shall be in accordance with the following:
ASME B16.5 or
ASME B16.47.
Non-ferrous flanges shall be in accordance with ASME B 16.24.
Ductile iron flanges shall be in accordance with ASME B 16.42.
Raised-face flanges shall not be joined to flat-faced cast iron, ductile iron or nonferrous material flanges. [NFPA 54:5.6.10.2]
Standard facings shall be permitted for use under this code. Where 150 psi (1034 kPa) steel flanges are bolted to Class 125 cast-iron flanges, the raised face on the steel flange shall be removed. [NFPA 54:5.6.10.3]
Lapped flanges shall be used only aboveground or in exposed locations accessible for inspection. [NFPA 54:5.6.10.4]
The material for gaskets shall be capable of withstanding the design temperature and pressure of the piping system and the chemical constituents of the gas being conducted without change to its chemical and physical properties. The effects of fire exposure to the joint shall be considered in choosing the material.
Acceptable materials shall include the following:
Metal (plain or corrugated)
Composition
Aluminum o-rings
Spiral-wound metal gaskets
Rubber-faced phenolic
Elastomeric
Metallic flange gaskets shall be in accordance with ASME B16.20.
Non-metallic flange gaskets shall be in accordance with ASME B16.21.
Full-face flange gaskets shall be used with all non-steel flanges.
When a flanged joint is separated, the gasket shall be replaced.
Gas meters shall be selected for the maximum expected pressure and permissible pressure drop. [NFPA 54:5.7.1]
Gas meters shall be located in ventilated spaces readily accessible for examination, reading, replacement, or necessary maintenance.
Gas meters shall not be placed where they will be subjected to damage, such as adjacent to a driveway; under a fire escape; in public passages, halls, or where they will be subject to excessive corrosion or vibration.
Gas meters shall not be located where they will be subjected to extreme temperatures or sudden extreme changes in temperature or in areas where they are subjected to temperatures beyond those recommended by the manufacturer.
Gas meters shall be supported or connected to rigid piping so as not to exert a strain on the meters. Where flexible connectors are used to connect a gas meter to downstream piping at mobile homes in mobile home parks, the meter shall be supported by a post or bracket placed in a firm footing or by other means providing equivalent support.
Meters shall be protected against overpressure, backpressure, and vacuum.
Gas piping at multiple meter installations shall be marked by a metal tag or other permanent means designating the building or the part of the building being supplied and attached by the installing agency.
A line pressure regulator or gas appliance pressure regulator, as applicable, shall be installed where the gas supply pressure exceeds that at which the branch supply line or appliances are designed to operate or vary beyond design pressure limits.
Line pressure regulators shall be listed in accordance with CSA Z21.80.
The gas pressure regulator shall be accessible for servicing.
Pressure regulators shall be protected against physical damage.
Line pressure regulators shall comply with all of the following:
An independent vent to the exterior of the building, sized in accordance with the regulator manufacturer's instructions, shall be provided where the location of a regulator is such that a ruptured diaphragm will cause a hazard. Where more than one regulator is at a location, each regulator shall have a separate vent to the outdoors or, if approved by the Authority Having Jurisdiction, the vent lines shall be permitted to be manifolded in accordance with accepted engineering practices to minimize backpressure in the event of diaphragm failure. Materials for vent piping shall be in accordance with Section 1208.6 through Section 1208.6.12.3.
Exception: A regulator and vent limiting means combination listed as complying with CSA Z21.80 shall be permitted to be used without a vent to the outdoors.
The vent shall be designed to prevent the entry of water, insects, or other foreign materials that could cause a blockage.
The regulator vent shall terminate at least 3 feet (914 mm) from a source of ignition.
At locations where regulators might be submerged during floods, a special antiflood-type breather vent fitting shall be installed, or the vent line shall be extended above the height of the expected flood waters.
A regulator shall not be vented to the appliance flue or exhaust system.
For venting of gas appliance pressure regulators see Section 507.21.
The discharge of vents shall be in accordance with the following requirements:
The discharge stacks, vents, or outlet parts of all pressure-relieving and pressure-limiting devices shall be located so that gas is safely discharged to the outdoors. Discharge stacks or vents shall be designed to prevent the entry of water, insects, or other foreign material that could cause a blockage.
The discharge stack or vent line shall be at least the same size as the outlet of the pressure-relieving device.
Valved and regulated bypasses shall be permitted to be placed around gas line pressure regulators where continuity of service is imperative.
Line pressure regulators at multiple regulator installations shall be marked by a metal tag or other permanent means designating the building or the part of the building being supplied.
Where the serving gas supplier delivers gas at a pressure greater than 2 psi (14 kPa) for piping systems serving appliances designed to operate at a gas pressure of 14 inches water column (3.5 kPa) or less, overpressure protection devices shall be installed. Piping systems serving equipment designed to operate at inlet pressures greater than 14 inches water column (3.5 kPa) shall be equipped with overpressure protection devices as required by the appliance manufacturer's installation instructions.
Where piping systems serving appliances designed to operate with a gas supply pressure of 14 inches water column (3.5 kPa) or less are required to be equipped with overpressure protection by Section 1208.9, each overpressure protection device shall be adjusted to limit the gas pressure to each connected appliance to 2 psi (14 kPa) or less upon a failure of the line pressure regulator.
Where piping systems serving appliances designed to operate with a gas supply pressure greater than 14 inches water column (3.5 kPa) are required to be equipped with overpressure protection by Section 1208.9, each over-pressure protection device shall be adjusted to limit the gas pressure to each connected appliance as required by the appliance manufacturer's installation instructions.
Each overpressure protection device installed to meet the requirements of this section shall be capable of limiting the pressure to its connected appliance(s) as required by this section independently of any other pressure control equipment in the piping system.
Each gas piping system for which an overpressure protection device is required by this section shall be designed and installed so that a failure of the primary pressure control device(s) is detectable.
If a pressure relief valve is used to meet the requirements of this section, it shall have a flow capacity such that the pressure in the protected system is maintained at or below the limits specified in Section 1208.10 under the following conditions:
The line pressure regulator for which the relief valve is providing overpressure protection has failed wide open.
The gas pressure at the inlet of the line pressure regulator for which the relief valve is providing over-pressure protection is not less than the regulator's normal operating inlet pressure.
Protective devices shall be installed as close to the equipment as practical where the design of the equipment connected is such that air, oxygen, or standby gases are capable of being forced into the gas supply system.
Gas and air combustion mixers incorporating double diaphragm "zero" or "atmosphere" governors or regulators shall require no further protection unless connected directly to compressed air or oxygen at pressures of 5 psi (34 kPa) or more.
Protective devices shall include, but not be limited to the following:
Check valves.
Three-way valves (of the type that completely closes one side before starting to open the other side).
Reverse flow indicators controlling positive shutoff valves.
Normally closed air-actuated positive shutoff pressure regulators.
A protective device shall be installed between the meter and the appliance or equipment if the operation of the appliance or equipment is such that it could produce a vacuum or a dangerous reduction in gas pressure at the meter. Such protective devices include, but are not limited to, mechanical, diaphragm-operated, or electrically operated low-pressure shutoff valves.
Shutoff valves shall be approved and shall be selected giving consideration to pressure drop, service involved, emergency use, and reliability of operation. Shutoff valves of size 1 inch (25 mm) National Pipe Thread and smaller shall be listed.
Piping systems shall be designed to prevent failure from thermal expansion or contraction.
Where local conditions include earthquake, tornado, unstable ground, or flood hazards, special consideration shall be given to increased strength and flexibility of piping supports and connections. [NFPA 54:5.14.2]
Where automatic excess flow valves are installed, they shall be listed to CSA Z21.93 and shall be sized and installed in accordance with the manufacturer's instructions.
Underground gas piping shall be installed with sufficient clearance from any other underground structure to avoid contact therewith, to allow maintenance, and to protect against damage from proximity to other structures. In addition, underground plastic piping shall be installed with sufficient clearance or shall be insulated from sources of heat to prevent the heat from impairing the serviceability of the pipe.
Underground piping systems shall be installed with a minimum of 12 inches (305 mm) of cover. The minimum cover shall be increased to 18 inches (457 mm) if external damage to the pipe or tubing from external forces is likely to result. Where a minimum of 12 inches (305 mm) of cover cannot be provided, the pipe shall be installed in conduit or bridged (shielded).
The trench shall be graded so that the pipe has a firm, substantially continuous bearing on the bottom of the trench.
Where flooding of the trench is done to consolidate the backfill, care shall be exercised to see that the pipe is not floated from its firm bearing on the trench bottom.
Steel pipe and steel tubing installed underground shall be installed in accordance with Section 1210.1.3.1 through Section 1210.1.3.9.
Zinc coating (galvanizing) shall not be deemed adequate protection for underground gas piping.
Underground piping shall comply with one or more of the following unless approved technical justification is provided to demonstrate that protection is unnecessary:
The piping shall be made of a corrosion-resistant material that is suitable for the environment in which it will be installed.
Pipe shall have a factory-applied, electrically insulating coating. Fittings and joints between sections of coated pipe shall be coated in accordance with the coating manufacturer's instructions.
The piping shall have a cathodic protection system installed, and the system shall be maintained in accordance with Section 1210.1.3.3 or Section 1210.1.3.6.
Cathodic protection systems shall be monitored by testing, and the results shall be documented. The test results shall demonstrate one of the following:
A pipe-to-soil voltage of —0.85 volts or more negative is produced, with reference to a saturated copper-copper sulfate half cell.
A pipe-to-soil voltage of —0.78 volts or more negative is produced, with reference to a saturated K.C1 calomel half cell.
A pipe-to-soil voltage of —0.80 volts or more negative is produced, with reference to a silver-silver chloride half cell.
Compliance with a method described in Appendix D of Title 49 of the code of Federal Regulations, Part 192.
Sacrificial anodes shall be tested in accordance with the following:
Upon installation of the cathodic protection system, except where prohibited by climatic conditions, in which case the testing shall be performed not later than 180 days after the installation of the system.
12 to 18 months after the initial test.
Upon successful verification testing in accordance with Section 1210.1.3.4(1) and Section 1210.1.3.4(2), periodic follow-up testing shall be performed at intervals not to exceed 36 months.
Systems failing a test shall be repaired not more than 180 days after the date of the failed testing. The testing schedule shall be restarted as required in Section 1210.1.3.4(1) and Section 1210.1.3.4(2), and the results shall comply with Section 1210.1.3.3.
Impressed current cathodic protection systems shall be inspected and tested in accordance with the following schedule:
The impressed current rectifier voltage output shall be checked at intervals not exceeding two months.
The pipe-to-soil voltage shall be tested at least annually.
Documentation of the results of the two most recent tests shall be retained.
Where dissimilar metals are joined underground, an insulating coupling or fitting shall be used.
Steel risers, other than anodeless risers, connected to plastic piping shall be cathodically protected by means of a welded anode.
Where the formation of hydrates or ice is known to occur, the piping shall be protected against freezing.
Diagram
Underground piping, where installed through the outer foundation or basement wall of a building shall be encased in a protective sleeve or protected by an approved device or method. The space between the gas piping and the sleeve and between the sleeve and the wall shall be sealed to prevent entry of gas and water.
Diagram
Where gas piping is installed underground beneath buildings, the piping shall be either of the following:
Encased in an approved conduit designed to withstand the imposed loads and installed in accordance with Section 1210.1.6.1 or Section 1210.1.6.2.
A piping or encasement system listed for installation beneath buildings.
The conduit shall extend into an accessible 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 a gas leakage. Where the end sealing is of a type that retains the full pressure of the pipe, the conduit shall be designed for the same pressure as the pipe. The conduit shall extend at least 4 inches (102 mm) outside the building, be vented outdoors above finished ground level, and 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.
Plastic piping shall be installed outdoors, underground only.
Exceptions:
Plastic piping shall be permitted to terminate aboveground where an anodeless riser is used.
Plastic piping shall be permitted to terminate with a wall head adapter aboveground in buildings, including basements, where the plastic piping is inserted in a piping material permitted for use in buildings.
Connections made between metallic and plastic piping shall be made with fittings conforming to one of the following:
ASTM D2513, Category I transition fittings
ASTM F1973
ASTM F2509
An electrically continuous corrosion-resistant tracer shall be buried with the plastic pipe to facilitate locating. The tracer shall be one of the following:
A product specifically designed for that purpose.
Insulated copper conductor not less than 14 AWG.
Where tracer wire is used, access shall be provided from aboveground, or one end of the tracer wire or tape shall be brought aboveground at a building wall or riser.
Piping installed aboveground shall be securely supported and located where it will be protected from physical damage. Where passing through an exterior wall, the piping shall also be protected from corrosion by coating or wrapping with an inert material approved for such applications. The piping shall be sealed around its circumference at the point of the exterior penetration to prevent the entry of water, insects, and rodents. Where piping is encased in a protective pipe sleeve, the annular spaces between the gas piping and the sleeve and between the sleeve and the wall opening shall be sealed.
The installation of gas piping shall not cause structural stresses within building components to exceed allowable design limits. Approval shall be obtained before any beams or joists are cut or notched.
Piping for other than dry gas conditions shall be sloped not less than 1/4 inch in 15 feet (6.4 mm in 4.6 m) to prevent traps.
Gas piping shall be permitted to be installed in accessible spaces between a fixed ceiling and a dropped ceiling, whether or not such spaces are used as a plenum. Valves shall not be located in such spaces.
Exception: Appliance or equipment shutoff valves required by this code shall be permitted to be installed in accessible spaces containing vented appliances.
Gas piping inside any building shall not be installed in or through a clothes chute, chimney or gas vent, dumbwaiter, elevator shaft, or air duct, other than combustion air ducts.
Exception: Ducts used to provide ventilation air in accordance with Section 506.0 or to above-ceiling spaces in accordance with Section 1210.2.2.1.
Piping shall be supported with metal pipe hooks, metal pipe straps, metal bands, metal brackets, metal hangers, or building structural components, approved for the size of piping; of adequate strength and quality; and located at intervals to prevent or damp out excessive vibration. Piping shall be anchored to prevent undue strains on connected appliances and equipment and shall not be supported by other piping. Pipe hangers and supports shall conform to the requirements of MSS SP-58.
Spacing of supports in gas piping installations shall not exceed the distance shown in Table 1210.2.4.1. Spacing of supports for CSST shall be in accordance with the CSST manufacturer's instructions.
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 system shall be designed and installed, so they are not disengaged by movement of the supported piping.
Gas piping installed on the roof surfaces shall be elevated above the roof surface and shall be supported in accordance with Table 1210.2.4.1.
Gas piping in concealed locations shall be installed in accordance with this section.
Where gas piping is to be concealed, connections shall be of the following type:
Pipe fittings such as elbows, tees, couplings, and right/left nipple/couplings.
Joining tubing by brazing (see Section 1208.6.11.2).
Fittings listed for use in concealed spaces or that have been demonstrated to sustain, without leakage, forces due to temperature expansion or contraction, vibration, or fatigue based on their geographic location, application, or operation.
Where necessary to insert fittings in the gas pipe that has been installed in a concealed location, the pipe shall be reconnected by welding, flanges, or the use of a right/left nipple/coupling.
Concealed gas piping shall not be located in solid partitions.
This provision shall not apply to tubing that pierces walls, floors, or partitions. Tubing installed vertically and horizontally inside hollow walls or partitions without protection along its entire concealed length shall meet the following requirements:
A steel striker barrier not less than 0.0508 of an inch (1.3 mm) thick, or equivalent, is installed between the tubing and the finished wall and extends at least 4 inches (102 mm) beyond concealed penetrations of plates, firestops, wall studs, and similar construction features.
The tubing is installed in single runs and is rigidly secured.
In industrial occupancies, gas piping in solid floors such as concrete shall be laid in channels in the floor and covered to permit access to the piping with minimum damage to the building. Where piping in floor channels is exposed to excessive moisture or corrosive substances, the piping shall be protected in an approved manner.
In other than industrial occupancies and where approved by the Authority Having Jurisdiction, gas piping embedded in concrete floor slabs constructed with Portland cement shall be surrounded with a minimum of 11/2 inches (38 mm) of concrete and shall not be in physical contact with other metallic structures such as reinforcing rods or electrically neutral conductors. All piping, fittings, and risers shall be protected against corrosion in accordance with Section 1208.6.9. Piping shall not be embedded in concrete slabs containing quick-set additives or cinder aggregate.
Where gas piping exceeding 5 psi (34 kPa) is located within vertical chases in accordance with Section 1208.5(2), the requirements of Section 1210.4.1 through Section 1210.4.3 shall apply.
Where pressure reduction is required in branch connections for compliance with Section 1208.5, such reduction shall take place either inside the chase or immediately adjacent to the outside wall of the chase. Regulator venting and downstream overpressure protection shall comply with Section 1208.8.4 and Section 1208.9 through Section 1208.10.4. The regulator shall be accessible for service and repair, and vented in accordance with one of the following:
Where the fuel gas is lighter than air, regulators equipped with a vent limiting means shall be permitted to be vented into the chase. Regulators not equipped with a vent limiting means shall be permitted to be vented either directly to the outdoors or to a point within the top 1 foot (305 mm) of the chase.
Where the fuel gas is heavier than air, the regulator vent shall be vented only directly to the outdoors.
Chase construction shall comply with local building codes with respect to fire resistance and protection of horizontal and vertical openings.
A chase shall be ventilated to the outdoors and only at the top. The opening(s) shall have a minimum free area [in square inches (square meters)] equal to the product of one-half of the maximum pressure in the piping [in pounds per square inch (kilopascals)] times the largest nominal diameter of that piping [in inches (millimeters)], or the cross-sectional area of the chase, whichever is smaller. Where more than one fuel gas piping system is present, the free area for each system shall be calculated, and the largest area used.
Changes in direction of gas pipe shall be made by the use of fittings, factory bends, or field bends.
Metallic pipe bends shall comply with the following:
Bends shall be made with bending equipment and procedures intended for that purpose.
Bends shall be smooth and free from buckling, cracks, or other evidence of mechanical damage.
The longitudinal weld of the pipe shall be near the neutral axis of the bend.
The pipe shall not be bent through an arc of more than 90 degrees (1.57 rad).
The inside radius of a bend shall be not less than six times the outside diameter of the pipe.
Plastic pipe bends shall comply with the following:
The pipe shall not be damaged, and the internal diameter of the pipe shall not be effectively reduced.
Joints shall not be located in pipe bends.
The radius of the inner curve of such bends shall not be less than 25 times the inside diameter of the pipe.
Where the piping manufacturer specifies the use of special bending tools or procedures, such tools or procedures shall be used.
Factory-made welding elbows or transverse segments cut therefrom shall have an arc length measured along the crotch at least 1 inch (25.4 mm) for pipe sizes 2 inches (50 mm) and larger.
For other than dry gas conditions, a drip shall be provided at a point in the line of pipe where condensate could collect. Where required by the Authority Having Jurisdiction or the serving gas supplier, a drip shall also be provided at the outlet of the meter. This drip shall be so installed as to constitute a trap wherein an accumulation of condensate shuts off the flow of gas before it runs back into the meter.
All drips shall be installed only in such locations that they are readily accessible to permit cleaning or emptying. A drip shall not be located where the condensate is likely to freeze.
The installation of sediment traps shall be in accordance with Section 1212.9.
Outlets shall be located and installed in accordance with the following requirements:
The outlet fittings or piping shall be securely fastened in place.
Outlets shall not be located behind doors.
Outlets shall be located far enough from floors, walls, patios, slabs, and ceilings to permit the use of wrenches without straining, bending, or damaging the piping.
The unthreaded portion of gas piping outlets shall extend not less than 1 inch (25.4 mm) through finished ceilings or indoor or outdoor walls.
The unthreaded portion of gas piping outlets shall extend not less than 2 inches (51 mm) above the surface of floors or outdoor patios or slabs.
The provisions of Section 1210.7(4) and Section 1210.7(5) shall not apply to listed quick-disconnect devices of the flush-mounted type or listed gas convenience outlets. Such devices shall be installed in accordance with the manufacturer's installation instructions.
Each outlet, including a valve, shall be closed gastight with a threaded plug or cap immediately after installation and shall be left closed until the appliance or equipment is connected thereto. Where an appliance or equipment is disconnected from an outlet, and the outlet is not to be used again immediately, it shall be capped or plugged gastight.
Exceptions:
Laboratory appliances installed in accordance with Section 1212.3.1 shall be permitted.
The use of a listed quick-disconnect device with integral shutoff or listed gas convenience outlet shall be permitted.
Appliance shutoff valves installed in fireplaces shall be removed, and the piping capped gastight where the fireplace is used for solid-fuel burning.
Where a branch outlet is placed on the main supply line before it is known what size pipe will be connected to it, the outlet shall be of the same size as the line that supplies it.
An accessible gas shutoff valve shall be provided upstream of each gas pressure regulator. Where two gas pressure regulators are installed in series in a single gas line, a manual valve shall not be required at the second regulator.
Main gas shutoff valves controlling several gas piping systems shall be readily accessible for operation and installed to be protected from physical damage. They shall be marked with a metal tag or other permanent means attached by the installing agency so that the gas piping systems supplied through them are readily identified.
In multiple-tenant buildings supplied through a master meter, through one service regulator where a meter is not provided, or where meters or service regulators are not readily accessible from the appliance or equipment location, an individual shutoff valve for each apartment or tenant line shall be provided at a convenient point of general accessibility. In a common system serving a number of individual buildings, shutoff valves shall be installed at each building.
An exterior shutoff valve to permit turning off the gas supply to each building in an emergency shall be provided. The emergency shutoff valves shall be plainly marked as such and their locations posted as required by the Authority Having Jurisdiction.
Each laboratory space containing two or more gas outlets installed on tables, benches, or in hoods in educational, research, commercial and industrial occupancies shall have a single shutoff valve through which all such gas outlets are supplied. The shutoff valve shall be accessible, located within the laboratory or adjacent to the laboratory's egress door, and identified.
No device shall be placed inside the gas piping or fittings that reduces the cross-sectional area or otherwise obstructs the free flow of gas, except where an allowance in the piping system design has been made for such a device and where approved by the Authority Having Jurisdiction.
Where gas-air mixing machines are employed to produce mixtures above or below the flammable range, they shall be provided with stops to prevent adjustment of the mixture to within or approaching the flammable range.
Systems containing flammable gas-air mixtures shall be in accordance with Section 1210.12.1 through Section 1210.12.6.
A central premix system with a flammable mixture in the blower or compressor shall consist of the following components:
Gas-mixing machine in the form of an automatic gas-air proportioning device combined with a downstream blower or compressor.
Flammable mixture piping, minimum Schedule 40.
Automatic firecheck(s).
Safety blowout(s) or backfire preventers for systems utilizing flammable mixture lines above 21/2 inches (65 mm) nominal pipe size (NPS) or the equivalent.
The following components shall also be permitted to be utilized in any type of central premix system:
Flowmeter(s)
Flame arrester(s)
Gas-mixing machines shall have nonsparking blowers and shall be constructed so that a flashback does not rupture machine casings.
A mixing blower system shall be limited to applications with minimum practical lengths of mixture piping, limited to a maximum mixture pressure of 10 inches water column (2.5 kPa) and limited to gases containing no more than 10 percent hydrogen. The blower shall be equipped with a gas-control valve at its air entrance arranged so that gas is admitted to the airstream, entering the blower in proper proportions for correct combustion by the type of burners employed, the said gas-control valve being of either the zero governor or mechanical ratio valve type that controls the gas and air adjustment simultaneously. No valves or other obstructions shall be installed between the blower discharge and the burner or burners.
Installation of gas-mixing machines shall comply with the following:
The gas-mixing machine shall be located in a well-ventilated area or in a detached building or cutoff room provided with room construction and explosion vents in accordance with sound engineering principles. Such rooms or below-grade installations shall have adequate positive ventilation.
Where gas-mixing machines are installed in well-ventilated areas, the type of electrical equipment shall be in accordance with NFPA 70, for general service conditions unless other hazards in the area prevail. Where gas-mixing machines are installed in small detached buildings or cutoff rooms, the electrical equipment and wiring shall be installed in accordance with NFPA 70 for hazardous locations.
Air intakes for gas-mixing machines using compressors or blowers shall be taken from outdoors whenever practical.
Controls for gas-mixing machines shall include interlocks and a safety shutoff valve of the manual reset type in the gas supply connection to each machine arranged to automatically shut off the gas supply in the event of high or low gas pressure. Except for open-burner installations only, the controls shall be interlocked so that the blower or compressor stops operating following a gas supply failure. Where a system employs pressurized air, means shall be provided to shut off the gas supply in the event of air failure.
Centrifugal gas-mixing machines in parallel shall be reviewed by the user and equipment manufacturer before installation, and means or plans for minimizing the effects of downstream pulsation and equipment overload shall be prepared and utilized as needed.
Automatic firechecks and safety blowouts or backfire preventers shall be provided in piping systems distributing flammable air-gas mixtures from gas-mixing machines to protect the piping and the machines in the event of flashback, in accordance with the following:
Approved automatic firechecks shall be installed upstream as close as practical to the burner inlets following the firecheck manufacturer's instructions.
A separate manually operated gas valve shall be provided at each automatic firecheck for shutting off the flow of the gas-air mixture through the firecheck after a flashback has occurred. The valve shall be located upstream as close as practical to the inlet of the automatic firecheck.
Caution: These valves shall not be reopened after a flashback has occurred until the firecheck has cooled sufficiently to prevent re-ignition of the flammable mixture and has been reset properly.
A safety blowout or backfiring preventer shall be provided in the mixture line near the outlet of each gas-mixing machine where the size of the piping is larger than 2 1/2 inches (65 mm) NPS, or equivalent, to protect the mixing equipment in the event of an explosion passing through an automatic firecheck. The manufacturer's instructions shall be followed when installing these devices, particularly after a disc has burst. The discharge from the safety blowout or backfire preventer shall be located or shielded so that particles from the ruptured disc cannot be directed towards personnel. Wherever there are interconnected installations of gas-mixing machines with safety blowouts or backfire preventers; provision shall be made to keep the mixture from other machines from reaching any ruptured disc opening. Check valves shall not be used for this purpose.
Large-capacity premix systems provided with explosion heads (rupture discs) to relieve excessive pressure in pipelines shall be located at and vented to a safe outdoor location. Provisions shall be provided for automatically shutting off the supply of the gas-air mixture in the event of a rupture.
Each aboveground portion of a gas piping system other than 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 appliance grounding conductor of the circuit supplying that appliance.
CSST gas piping systems, and gas piping systems containing one or more segments of CSST, shall be bonded to the electrical service grounding electrode system or, where provided, lightning protection grounding electrode system.
The bonding jumper shall connect to a metallic pipe, pipe fitting, or CSST fitting.
The bonding jumper shall not be smaller than 6 AWG copper wire or equivalent.
The length of the jumper between the connection to the gas piping system and the grounding electrode system shall not exceed 75 feet (22 875 mm). Any additional electrodes shall be bonded to the electrical service grounding electrode system or, where provided, lightning protection grounding electrode system.
Bonding connections shall be in accordance with NFPA 70.
Devices used for the bonding connection shall be listed for the application in accordance with UL 467.
Gas piping shall not be used as a grounding conductor or electrode.
Where a lightning protection system is installed, the bonding of the gas piping shall be in accordance with NFPA 780.
Electrical circuits shall not utilize gas piping or components as conductors.
Exception: Low-voltage (50V or less) control circuits, ignition circuits, and electronic flame detection device circuits shall be permitted to make use of piping or components as a part of an electric circuit.
All electrical connections between the wiring and electrically operated control devices in a piping system shall conform to the requirements of NFPA 70.
Any essential safety control depending on electric current as the operating medium shall be of a type that will shut off (fail safe) the flow of gas in the event of current failure.
Appliances and equipment shall be connected to the building piping in compliance with Section 1212.5 through Section 1212.8 by one of the following:
Rigid metallic pipe and fittings.
Semirigid metallic tubing and metallic fittings. Aluminum alloy tubing shall not be used in exterior locations.
A listed connector in compliance with CSA Z21.24. The connector shall be used in accordance with the manufacturer's installation instructions and shall be in the same room as the appliance. Only one connector shall be used per appliance.
A listed connector in compliance with CSAZ21.75. Only one connector shall be used per appliance.
CSST where installed in accordance with the manufacturer's installation instructions.
Listed nonmetallic gas hose connectors in accordance with Section 1212.3.
Unlisted gas hose connectors for use in laboratories and educational facilities in accordance with Section 1212.4.
Connectors used with commercial cooking appliances that are moved for cleaning and sanitation purposes shall be installed in accordance with the connector manufacturer's installation instructions. Such connectors shall be listed in accordance with CSA Z21.69.
Movement of appliances with casters shall be limited by a restraining device installed in accordance with the connector and appliance manufacturer's installation instructions.
Suspended low-intensity infrared tube heaters shall be connected to the building piping system with a connector listed for the application in accordance with CSA Z21.24 as follows:
The connector shall be installed in accordance with the tube heater installation instructions and shall be in the same room as the appliance.
Only one connector shall be used per appliance.
Listed gas hose connectors shall be installed in accordance with the manufacturer's installation instructions and in accordance with Section 1212.3.1 and Section 1212.3.2.
Indoor gas hose connectors shall be used only to connect laboratory, shop, and ironing appliances requiring mobility during operation and installed in accordance with the following:
An appliance shutoff valve shall be installed where the connector is attached to the building piping.
The connector shall be of minimum length and shall not exceed 6 feet (1829 mm).
The connector shall not be concealed and shall not extend from one room to another or pass through wall partitions, ceilings, or floors.
Where outdoor gas hose connectors are used to connect portable outdoor appliances, the connector shall be listed in accordance with CSA Z21.54 and installed in accordance with the following:
An appliance shutoff valve, a listed quick-disconnect device, or a listed gas convenience outlet shall be installed where the connector is attached to the supply piping and in such a manner to prevent the accumulation of water or foreign matter.
This connection shall be made only in the outdoor area where the appliance is to be used.
The connector length shall not exceed 15 feet (4572 mm).
Injection (Bunsen) burners used in laboratories and educational facilities shall be permitted to be connected to the gas supply by an unlisted hose.
Where portable industrial appliances, or appliances requiring mobility or subject to vibration, are connected to the building gas piping system by the use of a flexible hose, the hose shall be suitable and safe for the conditions under which it can be used.
Where industrial appliances requiring mobility are connected to the rigid piping by the use of swivel joints or couplings, the swivel joints or couplings shall be suitable for the service required, and only the minimum number required shall be installed.
Where industrial appliances subject to vibration are connected to the building piping system by the use of all metal flexible connectors, the connectors shall be suitable for the service required.
Where flexible connections are used, they shall be of the minimum practical length and shall not extend from one room to another or pass through any walls, partitions, ceilings, or floors. Flexible connections shall not be used in any concealed location. They shall be protected against physical or thermal damage and shall be provided with gas shutoff valves in readily accessible locations in rigid piping upstream from the flexible connections.
Each appliance connected to a piping system shall have an accessible, approved manual shutoff valve with a nondisplaceable valve member or a listed gas convenience outlet. Appliance shutoff valves and convenience outlets shall serve a single appliance only. The shutoff valve shall be located within 6 feet (1829 mm) of the appliance it serves. Where a connector is used, the valve shall be installed upstream of the connector. A union or flanged connection shall be provided downstream from the valve to permit removal of appliance controls. Shutoff valves serving decorative appliances shall be permitted to be installed in fireplaces if listed for such use.
Exceptions:
Shutoff valves shall be permitted to be accessibly located inside or under an appliance where such appliance is removed without removal of the shutoff valve.
Shutoff valves shall be permitted to be accessibly located inside wall heaters and wall furnaces listed for recessed installation where necessary maintenance is performed without removal of the shutoff valve.
Quick-disconnect devices used to connect appliances to the building piping shall be listed to CSA Z21.41. Where installed indoors, an approved manual shutoff valve with a non-displaceable valve member shall be installed upstream of the quick-disconnect device.
Appliances shall be permitted to be connected to the building piping by means of a listed gas convenience outlet, in conjunction with a listed appliance connector, installed in accordance with the manufacturer's installation instructions.
Gas convenience outlets shall be listed in accordance with CSA Z21.90 and installed in accordance with the manufacturer's installation instructions.
Where a sediment trap is not incorporated as a part of the appliance, a sediment trap shall be installed downstream of the appliance shutoff valve as close to the inlet of the appliance as practical, before the flex connector, where used at the time of appliance installation. The sediment trap shall be either a tee fitting with a capped nipple in the bottom outlet, as illustrated in Figure 1212.9, or other device recognized as an effective sediment trap. Illuminating appliances, ranges, clothes dryers, decorative appliances for installation in vented fireplaces, gas fireplaces, and outdoor grills shall not be required to be so equipped.
Piping shall be installed in a manner not to interfere with inspection, maintenance, or servicing of the appliance.
Liquefied petroleum gas facilities shall be in accordance with NFPA 58.
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.
Inspection shall consist of visual examination during or after manufacture, fabrication, assembly, or pressure tests.
Where repairs or additions are made following the pressure test, the affected piping shall be tested. Minor repairs and additions are not required to be pressure-tested provided that the work is inspected, and connections are tested with a noncorrosive leak-detecting fluid or other leak-detecting methods approved by the Authority Having Jurisdiction.
Where new branches are installed to new appliances the newly installed branch(es) 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 approved leak-detecting methods.
A piping system shall be tested as a complete unit or in sections. Under no circumstances shall a valve in a line be used as a bulkhead between gas in one section of the piping system and test medium in an adjacent section, unless 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 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.
The test medium shall be air, nitrogen, carbon dioxide, or an inert gas. OXYGEN SHALL NEVER BE USED.
Test preparation shall comply with Section 1213.2.1 through Section 1213.2.6.
Pipe joints, including welds, shall be left exposed for examination during the test.
Exception: Covered or concealed pipe end joints that have been previously tested in accordance with this code.
Expansion joints shall be provided with temporary restraints, where required, for the additional thrust load under test.
Appliances and equipment that are not to be included in the test shall be either disconnected from the piping or isolated by blanks, blind flanges, or caps. Flanged joints at which blinds are inserted to blank off other equipment during the test shall not be required to be tested.
Where the piping system is connected to appliances or equipment designed for operating pressures of less than the test pressure, such appliances or equipment shall be isolated from the piping system by disconnecting them and capping the outlet(s).
Where the piping system is connected to appliances or equipment designed for operating pressures equal to or greater than the test pressure, such appliances or equipment shall be isolated from the piping system by closing the individual appliance or equipment shutoff valve(s).
All testing of piping systems shall be performed in a manner that protects the safety of employees and the public during the test.
This inspection shall include an air, CO2, or nitrogen pressure test, at which time the gas piping shall stand a pressure of not less than 10 psi (69 kPa) gauge pressure. Test pressures shall be held for a length of time satisfactory to the Authority Having Jurisdiction but in no case less than 15 minutes with no perceptible drop in pressure. For welded piping, and for piping carrying gas at pressures in excess of 14 inches water column pressure (3.5 kPa), the test pressure shall be not less than 60 psi (414 kPa) and shall be continued for a length of time satisfactory to the Authority Having Jurisdiction, but in no case for less than 30 minutes. For CSST carrying gas at pressures in excess of 14 inches water column (3.5 kPa) pressure, the test pressure shall be not less than 30 psi (207 kPa) for 30 minutes. These tests shall be made using air, CO2, or nitrogen pressure and shall be made in the presence of the Authority Having Jurisdiction. Necessary apparatus for conducting tests shall be furnished by the permit holder. Test gauges used in conducting tests shall be in accordance with Section 318.0.
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.
The leakage shall be located by means of an approved gas detector, a noncorrosive leak detection fluid, or other approved leak detection methods.
Where leakage or other defects are located, the affected portion of the piping system shall be repaired or replaced and retested.
Leak checks using fuel gas shall be permitted in piping systems that have been pressure-tested in accordance with Section 1213.0.
During the process of turning gas on into a system of new gas piping, the entire system shall be inspected to determine that there are no open fittings or ends and that valves at 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.
Appliances and equipment shall not be placed in operation until after the piping system has been checked in accordance with Section 1213.5.2; connections to the appliance are checked for leakage and purged in accordance with Section 1213.6.
The purging of piping shall be in accordance with Section 1213.6.1 through Section 1213.6.3.
The purging of piping systems shall be in accordance with the provisions of Section 1213.6.1.1 through Section 1213.6.1.5 where the piping system meets either of the following:
The design operating gas pressure is greater than 2 psig (14 kPa).
The piping being purged contains one or more sections of pipe or tubing meeting the size and length criteria of Table 1213.6.1.
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 1213.6.1.4. Where gas piping meeting the criteria of Table 1213.6.1 is removed from service, the residual fuel gas in the piping shall be displaced with an inert gas.
Where piping containing gas is to be removed, the line shall be first disconnected from sources of gas and then thoroughly purged with air, water, or inert gas before cutting, or welding is done.
Where gas piping containing air and meeting the criteria of Table 1213.6.1 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 1213.6.1.4.
The open end of a piping system being pressure vented or purged shall discharge directly to an outdoor location. Purging operations shall comply with the following requirements:
The point of discharge shall be controlled with a shutoff valve.
The point of discharge shall be located at least 10 feet (3048 mm) from sources of ignition, at least 10 feet (3048 mm) from building openings, and at least 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 is in accordance with Section 1213.6.1.5.
Purging operations introducing fuel gas shall be stopped where 90 percent fuel gas by volume is detected within the pipe.
Persons not involved in the purging operations shall be evacuated from areas within 10 feet (3048 mm) of the point of discharge.
Combustible gas indicators shall be listed and calibrated in accordance with the manufacturer's instructions. Combustible gas indicators shall numerically display a volume scale from 0 percent to 100 percent in 1 percent or smaller increments.
The purging of piping systems shall be in accordance with the provisions of Section 1213.6.2.1 where the piping system meets both of the following:
The design operating pressure is 2 psig (14 kPa) or less.
The piping being purged is constructed entirely from pipe or tubing not meeting the size and length criteria of Table 1213.6.1.
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 appliance burner 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 1213.6.2.2. Purging shall be stopped where 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 calibrated or tested in accordance with the manufacturer's instructions. Combustible gas detectors shall be capable of indicating the presence of fuel gas.
After the piping system has been placed in operation, appliances and equipment shall be purged before being placed into operation.
The following regulations shall comply with this section and Section 1215.0, shall be the standard for the installation of gas piping. Natural gas regulations and tables are based on the use of a gas having a specific gravity of 0.60 and for undiluted liquefied petroleum gas, having a specific gravity of 1.50. Where gas of a different specific gravity is to be delivered, the specific gravity conversion factors provided by the serving gas supplier shall be used in sizing piping systems from the pipe sizing tables in this chapter.
The hourly volume of gas required at each piping outlet shall be taken as not less than the maximum hourly rating as specified by the manufacturer of the appliance or appliances to be connected to each such outlet.
Where the gas appliances to be installed have not been specified, Table 1208.4.1 shall be permitted to be used as a reference to estimate requirements of typical appliances.
To obtain the cubic feet per hour (m3/h) of gas required, divide the input of the appliances by the average Btu (kW•h) heating value per cubic foot (m3) of the gas. The average Btu (kW•h) per cubic foot (m3) of the gas in the area of the installation shall be permitted to be obtained from the serving gas supplier.
The size of the supply piping outlet for a gas appliance shall be not less than 1/2 of an inch in diameter (15 mm).
The size of a piping outlet for a mobile home shall be not less than 3/4 of an inch in diameter (20 mm).
Where the pipe size is to be determined using any of the methods in Section 1215.1.1 through Section 1215.1.3, the diameter of each pipe segment shall be obtained from the pipe sizing tables in Section 1215.2 or the sizing equations in Section 1215.3.
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 shall be sized as follows:
The pipe size of each section of the longest pipe run from the point of delivery to the most remote outlet shall be determined using the longest run of piping and the load of the section.
The pipe size of each section of branch piping not previously sized shall be determined using the length of piping from the point of delivery to the most remote outlet in each branch and the load of the section.
The pipe size for each section of higher pressure gas piping shall be determined using the longest length of piping from the point of delivery to the most remote line pressure regulator. The pipe size from the line pressure regulator to each outlet shall be determined using the length of piping from the regulator to the most remote outlet served by the regulator.