(under subclass 68.12) Apparatus including a pressure responsive valve controlling the fluid flow in response to the pressure thereof in addition to the control in response to the breaking of the frangible element.
SEE OR SEARCH THIS CLASS, SUBCLASS:
511+, for direct pressure responsive valves.
SEE OR SEARCH CLASS
220, Receptacles,
203.08, for a vent or valve in a removeable closure, said vent or valve designed to rupture when exposed to excessive pressure.