Water-bellows. A form of pump, like a bellows—of great antiquity.

Water-cap. The cover for discharge valves on a steam pump.

Water-end. The pump end of a steam-pump; in distinction from the steam end.

Water-hammer. A noise caused by the pulsative motion of water inside a steam pipe, resembling the blows of a hammer.

Water Ram. A hydraulic ram.

Working Barrel. The water end of a pump.

Yoke.

Whirlpool-chamber. A chamber attached to the discharge end of the centrifugal pump in which the whirling water gradually loses its rotation, thereby reducing friction.