1.1This specification covers self-contained automatic shut-off valves (also known as excess flow valves) for air or nitrogen service. They are intended to be installed as safety devices to quickly and automatically shut off flow under certain excess flow conditions caused by a downstream failure or casualty, such as a hose rupture.

1.2The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.