equilibrium valve

noun

1. (in a reciprocating engine) a valve opening a passage from one end of a cylinder to the other to equalize pressure upon both faces of the piston.

Word History and Origins

Origin of equilibrium valve¹

First recorded in 1870–75

Example Sentences

The equilibrium valve is unchanged, except that the rack is taken out and a link put in.

From Project Gutenberg

The speed of the engine is controlled by a centrifugal governor and an equilibrium valve.

From Project Gutenberg