Priming valve

(Steam Eng.) a spring safety valve applied to the cylinder of a steam engine for discharging water carried into the cylinder by priming.

See also: Priming

References in periodicals archive ?
No fuel is leaking under the heater, at the priming valve, the gravity feed adapter or the fuel control valve quick-disconnects.
A third vacuum priming valve is located at an intermediate high point on the forcemain on Cuba Road east of Buffalo Creek.
Wanner Engineering will introduce HydraCell C80 Series air-bleed priming valves at booth D-4770.