STOP VALVE WITH UNLOADED STOP Russian patent published in 2012 - IPC F16K3/24 F16K39/04 

FIELD: machine building.

SUBSTANCE: stop valve with an unloaded stop comprises lower and upper casings, a seat with a sealing surface, a plunger in the form of a hollow bushing with a sealing surface and through holes made in its bottom to create a plunger unloading chamber, a drive stem, a membrane bellow with folding shape of corrugations having end parts, the upper of which is tightly connected to the upper part of the plunger, and the lower one is tightly installed into the valve casing, providing for axial displacement of the plunger by the drive force during bellow compression. The inner cavity of the bellow via a channel made on the lower end part is communicated via a bypass line equipped with a stop device, with the working fluid pressure cavity "under the stop". The upper end part of the bellow is made so that it forms a plunger pair with the upper casing and a cavity between the upper casing and the external surface of the bellow. The average diameter of the bellow is made as equal to the average diameter of the sealing surface of the valve stop. The valve is equipped with the second bypass line with a stop device, providing for connection of the working fluid pressure cavity "onto the stop" with the external cavity of the bellow. Both channels of bypass lines are equipped with a check valve. Stop devices are made as normally open.

EFFECT: expansion of functional capabilities of a valve with an unloaded stop providing for its operation in case of double-sided direction of a working fluid flow.

3 cl, 1 dwg