Hydraulic valve

(Mach.)	A valve for regulating the distribution of water in the cylinders of hydraulic elevators, cranes, etc.
(Gas Works)	An inverted cup with a partition dipping into water, for opening or closing communication between two gas mains, the open ends of which protrude about the water.

Hydraulic Valve

a device in hydraulic machines and drives in which the dimensions of the operating channel vary as a result of the action of the hydraulic fluid passing through it. Hydraulic valves protect the hydraulic system and mechanisms of machines from overloads, provide a specified constant pressure in various branches of a hydraulic system, control the direction of fluid flow, regulate fluid pressure in the various branches of a hydraulic system, create a specified constant pressure drop in various parts of hydraulic systems, and provide a given sequence of actions of the working members in a machine for purposes of interlocking.

V. A. KHOKHLOV