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

When the stroke is completed, the “equilibrium valve” is opened, and the steam passes from above to the space below the piston, and an equilibrium of pressure being thus produced, the pump-rods descend, forcing the water from the pumps and raising the steam-piston.

From Project Gutenberg

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

From Project Gutenberg

A kind of expansion valve, often employed in marine engines of low speed, is the kind used in the Cornish engines, and known as the equilibrium valve.

From Project Gutenberg

Q.--Might not an equilibrium valve be so constructed by the interposition of springs, as to enable it to leave the cylinder face when an internal force is applied?

From Project Gutenberg

It is clear, that if such a valve were applied to a pump, no pressure of water within the pump would suffice to open it, neither would any pressure of water above the valve cause it to shut with violence; and if an equilibrium valve, therefore, be used as a pump valve at all, it must be opened and shut by mechanical means.

From Project Gutenberg