CHECK VALVE Russian patent published in 2023 - IPC F16K15/02 F16K31/145 

FIELD: valves.

SUBSTANCE: invention relates to check valves used in various systems, which are subject to the requirements of stable tightness at pressure drops of the working fluid (gas) from the outlet to the valve inlet, including a difference close to zero. In the check valve, seat 4 is movable, and shut-off element 6 is rigidly connected to body 1. The seat is located at the end of rod 4 with a through axial hole, which is hermetically connected to bellows 8 by means of disk 5, and the second end of the bellows is welded to the body. At the entrance to housing 1 there is a cavity with friction damper 9, which is clamped in it by locking element 6 and fifth cover 10 and inlet cover 2. The rod with seat 4 is installed in the guide holes of body 1 and friction damper 9. The cavity of the inlet cover is connected by channel 13 with the cavity of bellows 8. Spring 7 is installed in the cavity of bellows 8, with the force of which seat 4 is pressed against the valve (shut-off element 6). To reduce resistance, the rigidity of the bellows is chosen to be minimal, the bellows has welded corrugations.

EFFECT: reliable operation without vibrations of the moving parts of the valve and stable tightness at low pressure drops of the fluid.

1 cl, 1 dwg