This standard applies to check valves used in general industrial and medical compressed gas service designed for service pressures up to 3500 psi at 120 °F (24 130 kPa at 49 °C), and used in conjunction with cylinder valve or manifold connections specified by various standards of CGA. These connections may be incorporated as part of equipment; such as regulator inlet connections, manifold connections, or other high pressure hose line (pigtail) inlet and outlet connections.

This standard does not apply to check valves used as an integral part of a regulator, residual pressure cylinder valve, gas pump, or otherwise internal component of other equipment. This standard does not apply to cryogenic or liquefied gas check valves.

Flammable, toxic, high purity, or specialty gas applications can require additional specialized design requirements.

This standard does not prejudice the continued use of check valves in service or in inventory at a manufacturer's or user's site that were manufactured before the effective date of this standard. The effective date of this standard is one year from the date of publication of this edition, which is October 31, 2022. Check valves manufactured on and after the effective date of this standard shall be in compliance with this standard.