California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 7 - General Industry Safety Orders
Group 20 - Flammable Liquids, Gases and Vapors
Article 139 - Oxygen
Section 5504 - Piping, Tubing and Fittings

(a) Piping, tubing and fittings shall be suitable for oxygen service and for the pressures and temperatures involved.

(b) Piping and tubing installed after May 30, 1999, shall conform to ASME B31.3-1996, Process Piping, which is hereby incorporated by reference. Piping and tubing installed on or before May 30, 1999, shall conform to either the American National Standard Code for Pressure Piping, Petroleum Refinery Piping, ANSI B31.3-1973, or the updated version of the ANSI/ASME B31.3 standard in effect at the time of installation.

(c) Piping or tubing for operating temperatures below -20° F. shall be fabricated from materials meeting the impact test requirements of Paragraph UG-84 of ASME Boiler and Pressure Vessel Code, Section VIII Unfired Pressure Vessels (1974), when tested at the minimum operating temperature to which the piping may be subjected in service.

NOTE: Some materials suitable for low temperature piping are austenitic chromium-nickel alloy steels, copper, copper-silicon alloys, aluminum, and some brasses and bronzes.