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 10 - Gas Systems for Welding and Cutting
Article 86 - Manifolding of Cylinders to Headers for Shop Pipe Line Supply Systems and Pressure Reducing Regulators and Hose
Section 4835 - Fuel Gas Manifolds. (Acetylene, Liquefied Fuel Gases, and Nonliquified Gases Other than Acetylene.)

(a) Only cylinders containing gas at approximately equal pressures shall be manifolded.

(b) Except as provided in 4835 (c), fuel-gas cylinders connected to one manifold inside a building shall be limited to a total capacity not exceeding 300 pounds of liquified petroleum gas or 3,000 cubic feet of other fuel-gas. More than one manifold with connected cylinders may be located in the same room provided the manifolds are at least 50 feet apart or separated by a noncombustible barrier at least 50 feet apart or separated by a noncombustible barrier at least 5 feet high having a fire-resistance rating of at least one-half hour.

(c) Fuel-gas cylinders connected to one manifold having an aggregate capacity exceeding 300 pounds of liquified petroleum gas or 3,000 cubic feet of other fuel-gas shall be located outdoors, or in a separate building or room constructed in accordance with Section 4805(b).

(d) Special buildings or rooms, if provided, shall have no other occupancy except that they may be used for the storage of cylinders containing fuel gas and of drums of carbide; such buildings or rooms shall have no open flame for heating or lighting and shall be well ventilated. Signs shall be conspicuously posted in such rooms reading, "Danger No Smoking, Matches or Open Lights," or other equivalent wording.