scope:

This specification covers low pressure and high pressure aircraft oxygen filler valves.

The valves and fitting are classified as follows:

M7891LF - Low pressure valve (female) M7891LM - Low pressure valve (male) M7891HM - High pressure valve (male) M7891HF - High pressure fitting (female)

Unless otherwise specified, the valves and fittings and their associated plugs, tethers, handles, flanges, and caps are referred to as valves and fittings in this specification.

intended Use:

The filler valves are intended for use in recharging aircraft high pressure or low pressure gaseous oxygen systems or portable oxygen equipment.