California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 1 - Unfired Pressure Vessel Safety Orders
Article 5 - LP-Gas Systems
Section 480 - Pipes and Fittings for All Liquid Lines and for Vapor Lines Where the Pressure Exceeds 20 PSI

(a) All pipe between the container and first shutoff valve shall be Schedule 80 (extra heavy). All fittings between the container and first shutoff valve shall be steel as required by Section 480(c).

Aboveground piping in excess of 1 1/2 inch pipe size may be Schedule 40 when used beyond the first shutoff valve, providing:

(b) Piping outside of buildings may be either buried or installed aboveground and shall be well-supported and protected against mechanical injury. All underground piping shall be Schedule 80 and shall be buried not less than 18 inches below the surface of the ground, unless otherwise protected, and shall be protected from corrosion by approved corrosion-resistant material and by cathodic protection.

Voltage readings from the cathodic system shall be taken and recorded annually and shall produce a negative voltage of at least 0.85 volts with reference to a saturated copper-copper sulfide half-cell. Where impressed current is used, amperage and voltage readings shall be recorded at 6-month intervals.

(c) All steel fittings used with Schedule 80 pipe shall be Schedule 80 if butt welded, 3,000 pounds WOG if socket welded, and 2,000 pounds WOG forged steel if threaded. All other steel fittings shall have a rating of at least Schedule 40 if butt welded, and 2,000 pounds WOG if socket welded or threaded.

All steel valves and fittings shall have a steam rating of at least one hundred fifty (150) psi, ANSI standard, with a minimum WOG rating of 250 psi. Valves of material other than steel shall have a pressure rating of at least two hundred (200) psi steam, or four hundred (400) psi WOG. The manufacturer of LP-Gas valves shall stamp or otherwise permanently mark the valve body to indicate the pressure rating. Steam valves when used for LP-Gas service shall be refitted for such service. Valve seat material, packing, gaskets, etc., shall be resistant to the action of LP-Gas.

(d) The use of the following is prohibited:

(e) In addition to the valves required in NFPA 58, Section 2-3.3.2, all liquid and vapor connections shall be fitted with manually operated shutoff valves located as close to the container as practicable.

(f) Where containers are in liquid service or a combination of liquid and vapor service, all connections with manually operated shutoff valves shall be legibly labeled to indicate whether they communicate with the vapor or liquid space.