DRAIN AND SAFETY VALVE Russian patent published in 2012 - IPC F16K17/06 

FIELD: machine building.

SUBSTANCE: drain and safety valve has housing (11), camera (12) with inlet port (13) communicating with the interior space of the hydraulic system, and a side drain opening (14) communicating with the outer space. Inlet port (13) corresponds to seat (17) of the valve turned inward into chamber (12). The valve seat is connected with movable plunger (18), moving between a closed and open position of inlet port (13). There is pushing element (21) moving in the axial direction in chamber (12). There is at least one compressible spring (23) between pushing element (21) and plunger (18) which is able to hold the plunger in the closed position and allowing it to return to an open position of inlet port (13) only if preset internal pressure is available in the controlled hydraulic system. Preload of spring (23) is controlled by axial movement of pushing element (21) in order to establish and adjust pressure at a level at which plunger (18) should move from a closed position to open position of inlet port (13). Pushing element (21) is screwed onto threaded part (20) inside the chamber and is connected to control handle (22) in order to have regulatory axial movement or neutralisation of spring preload. Pushing element (21) has a radial part or locking ring (24) resting on locking ledge (25) in housing (11) of the valve ensuring maximum retracted position of element (21) after it is inserted into the housing. Control handle (22) is movably connected with pushing element (21) so that it disengages with it as soon as it is released after each adjustment of preload of spring (23). Handle (22) and the pushing device have an engaging insertion or teeth (26, 27) for coupling and uncoupling in the axial direction.

EFFECT: proper operation and protection of hydraulic equipment even at relatively high operating pressures.

5 cl, 2 dwg