(under subclass 535) Valves in which the valve is a cylindrical plug cooperating with a hollow cylindrical valve seat, there being ports in the cylindrical wall of either piston or seat which are opened and closed by reciprocating movement of the piston in the cylindrical seat.
SEE OR SEARCH THIS CLASS, SUBCLASS:
792, for piston type expansible chamber devices.
SEE OR SEARCH CLASS
251, Valves and Valve Actuation,
62+, for piston type fluid pressure actuators for valves, and subclasses 318+ for reciprocating valves of this class, and see the search notes thereto.