1208.11 Backpressure Protection. 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.

1208.10.1 Overpressure Protection Required. 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 overpressure protection device shall be adjusted to limit the gas pressure to each connected appliance as required by the appliance manufacturer’s installation instructions.

[NFPA 54:5.9.2.2] 1208.10.2 Overpressure Protection Devices. 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. [NFPA 54:5.9.2.3] 1208.10.3 Detection of Failure. 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. [NFPA 54:5.9.2.4] 1208.10.4 Flow Capacity. 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: (1) The line pressure regulator for which the relief valve

is providing overpressure protection has failed wide

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(1) The line pressure regulator for which the relief valve

is providing overpressure protection has failed wide open. (2) The gas pressure at the inlet of the line pressure reg ulator for which the relief valve is providing over

2019 CALIFORNIA PLUMBING CODE 227

FUEL GAS PIPING any other purpose or distributed to any other persons or parti es.

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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. [NFPA 54:5.10.1.1 – 5.10.1.2]

1208.11.1 Protective Devices. Protective devices shall include, but not be limited to the following: (1) Check valves. (2) Three-way valves (of the type that completely closes

one side before starting to open the other side).

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). [NFPA 54:7.1.2.1 (A) (B)] 1210.1.2 Trenches. The trench shall be graded so that the pipe has a firm, substantially continuous bearing on the bottom of the trench. [NFPA 54:7.1.2.2]

(2) Three-way valves (of the type that completely closes

one side before starting to open the other side). (3) Reverse flow indicators controlling positive shutoff

valves.

(3) Reverse flow indicators controlling positive shutoff

valves. (4) Normally closed air-actuated positive shutoff pres sure regulators. [NFPA 54:5.10.2]

1210.1.2.1 Backfilling. 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. [NFPA 54:7.1.2.3] 1210.1.3 Protection Against Corrosion. Steel pipe and steel tubing installed underground shall be installed in accordance with Section 1210.1.3.1 through Section 1210.1.3.9. [NFPA 54:7.1.3] 1210.1.3.1 Zinc Coating. Zinc coating (galvanizing) shall not be deemed adequate protection for underground gas piping. [NFPA 54:7.1.3.1] 1210.1.3.2 Underground Piping. Underground piping shall comply with one or more of the following unless approved technical justification is provided to demonstrate that protection is unnecessary: (1) The piping shall be made of a corrosion-resis tant material that is suitable for the environment

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(4) Normally closed air-actuated positive shutoff pres sure regulators. [NFPA 54:5.10.2]