This standard covers cylinder valve design, manufacture, and use including performance requirements such as operating temperature limits, pressure range, and flow capabilities. It also includes requirements such as materials, inlet and outlet connections, cleaning, qualification and production testing, maintenance, and reconditioning.

This standard also includes guidelines and requirements for the design, material selection, testing, and marking of cylinder valve protective caps. Except as noted in the last paragraph of this section, this standard is intended for valves for compressed gases packaged in U.S. Department of Transportation (DOT) and Transport Canada (TC) cylinders.

This standard provides information on valve selection, valve use guidelines, and valve protection caps (see Appendix A, Appendix B, and Section 10, respectively).

Standards incorporated by reference in this publication include the referenced document's procedures, criteria, and other requirements unless otherwise noted. This standard does not prejudice the continued use of valves in service or in inventory at a manufacturer's or user's site that were manufactured before the effective date of this standard provided the valves are identifiable to the original valve manufacturer and traceable to a manufacturing period. The identifying marks shall be permanent and visible on an installed valve.

The effective date of this standard is three years from the date of the publication of this edition, which was May 4, 2012. Valves manufactured on and after the effective date of this standard shall be in compliance with this standard.

This standard provides information on valve selection, valve use guidelines, and valve protection caps (see Appendix A, Appendix B, and Section 10, respectively).

This standard does not prejudice the continued use of valves in service or in inventory at a manufacturer's or user's site that were manufactured before the effective date of this standard provided the valves are identifiable to the original valve manufacturer and traceable to a manufacturing period. The identifying marks shall be permanent and visible on an installed valve.

This standard does not prohibit the use of valves that are Listed.

It applies to cylinders filled for individual use, cylinders filled individually for the purpose of assembling into a cylinder bundle, and for all cylinder bundle manifold outlet connections.

This standard does not apply to cylinders contained within an assembled cylinder bundle filled as one individual unit by use of the cylinder bundle manifold outlet connections. It also does not apply to medical gas mixtures (see CGA V-7.1)

For the assignment of ultra high integrity service (UHIS) connections for mixtures, see Appendix A.

For the purpose of this standard, a mixture is understood to be the purposeful combination of two or more components. An odorant shall be considered a component when added to either a pure gas or a mixture. Blanketing of a pure gas or mixture is not considered the generation of a new mixture.

Specialized vacuum-jacketed bayonet connections, which are required for some cryogenic products, are not included in this standard.

The Diameter Index Safety System supplements but does not replace:

• any of the means for medical gas identification currently in use;
• the Pin Index Safety System;
• the existing threaded outlet standards for cylinder valves; or
• automatic quick coupler valves that also provide noninterchangeable connections for medical gases and suction equipment.

CGA does not designate where the Diameter Index Safety System should be applied.

In all cases, the cause of the incidents was either the unexpected or intentional opening of the valve fitted to the gas cylinder during handling, filling, or venting of the cylinder. The consequences were that the cylinders went out of control after the valve opened.

This publication provides guidelines for the handling of gas cylinders during filling, storage, discharge, maintenance, periodic inspection, and transport equipped with quick release cylinder valves used in firefighting systems.

Quick release cylinder valves are used on cylinders typically containing carbon dioxide, nitrogen, or gas mixtures in firefighting systems.