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

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
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.