poppet valve

English

Noun

poppet valve (plural poppet valves)

1. (mechanics) 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) and which is operated by springs and possibly cams interacting with the shaft.
   • 1900, Patents for Inventions: Abridgments of Specifications, page 75:

     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.

   • 1959, David P. Morgan, editor, Steam's Finest Hour, Kalmbach Publishing Co., page 62:

     Chesapeake & Ohio's enormous L-2 4-6-4's with Franklin rotary-cam poppet valves boasted an engine weight of 221½ tons and were coal-minded Chessie's last bid to beat the passenger diesel with a reciprocating engine.