A stopcock opened and closed by means of a screw instead of a spigot.

plural of reversing valve

plural of flapper valve

(rail transport) In railway air braking systems, a valve that performs three functions.

plural of triple valve

snifting valve

plural of tail valve

A kind of valve used in toilets, water softeners, etc. to create a watertight seal in the tank that holds water until it needs to be flushed, at which point the valve is raised.

A valve which uses a hollow or double piston sliding in a cylinder to direct fluid along one of two paths

(rail transport, mechanical engineering) A device that retains some air pressure in a train's air brake cylinders even when the automatic brake valve is set to the fully-released position, used on steep downgrades to allow a degree of continuous braking effort to be maintained without depleting the pressure in the train's brakepipe (which would result in the loss of nearly all braking ability, causing a runaway).