(under the class definition) Subject matter wherein the valve actuator comprises a part of the flow confining means which
is exposed to the fluid at a region ahead of the cut-off point, or an extension of such part.
SEE OR SEARCH THIS CLASS, SUBCLASS:
149+, for valves operated by coupling or conduit motion, and see the search notes thereto.
SEE OR SEARCH CLASS
166, Wells,
334.1, and the subclasses there noted, for well devices comprising valves operated by motion of the conduit supporting the valve, and see subclass 316 for the line between Classes 166 and 251.