poppet valve

noun1

1. •
   A valve (as in an internal combustion engine) which consists of a sliding shaft with a disk on the end (the disk being shaped to alternately plug and unplug a matching port). Such a valve is opened by either a cam or a solenoid and is closed by either a spring or a solenoid.

   • This communication between the tank and pump is controlled by a float valve in the tanks and a cock in the pipe, while a poppet valve prevents the undrawn liquor going into the waste tank. — 1900