CGA V-9

This standard serves to inform cylinder valve users, buyers, sellers, manufacturers, and others in the safe and
proper use of cylinder valves.

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.