BALL VALVE SADDLES CONTROL NON-RETURN VALVES Russian patent published in 2018 - IPC F16K31/04 F16K15/00 

FIELD: machine building.

SUBSTANCE: invention relates to the field of mechanical engineering, namely, to non-return valves with a servo drive. Valve contains case with a central cavity, communicating with the executed in it two working channels. In the central cavity there is a distribution mechanism including a plunger with the possibility of moving along the axis of the cavity, made in the form of a coil, the rod of which is located in a support formed in the middle of the central cavity, and from the ends is provided with cheeks made in the form of pistons. Lower piston is clamped by a spiral spring located in the lower chamber of the central cavity in which a slide valve is placed coaxially with the longitudinal holes in the body and in the plunger. Body is made of three elements: middle, upper and lower. Connector between the bottom cover and the body is sealed with a rubber ring. Said central cavity is extended to all three of said elements, and in the upper cover it has the shape of a chamber in which an upper piston is arranged, connected to the spool pin, provided with rubber rings in the areas of mating with the rod and the cylindrical lateral surface of said chamber. In the lower part, the central cavity forms a two-dimensional two-step recess, in the lower stage of which the indicated spring is located, carrying a spool on the upper end with the possibility of pressing the plunger upwardly through the mating surface of the corresponding hole in the lower piston, sealingly closing the access from the central cavity of the body to said opening. Lower piston is installed with a clearance relative to the surface of the central cavity and is provided with sealing rings of polymer material pressed in the periphery of its lateral sides, made with the possibility of interface with the end surface of the middle part of the body and with the end surface of the bottom cover. Said support of the spool pin is made in the form of a tide in the central cavity in which a rubber ring interfaced with the rod is mounted. In the upper cover, a control channel F with a connection is made for connection to the ball valve drive control unit connected to the selective valve connected to the ball valve nozzle with higher pressure of the working fluid. Lower cover has a first working channel D for connecting to the inner cavity N in the ball valve body. Channels of the check valve are provided with fittings. Second working channel E is connected to the cavities L of the ball valve, formed by the outer seals of the saddles. Drainage channel G is configured to discharge the working medium into the atmosphere from the cavity of the check valve body. Drainage channel I is configured to discharge air into the atmosphere from the cavity between the piston and the housing. Plunger is adapted to hermetically seal the connection between the channel G and the channel D by the upper sealing ring of the lower piston in its uppermost position and between the channel D and the channel F by the spool. In the lowest position of the lower piston, its lower sealing ring sealingly closes the connection between the channel D and the channels G and E. Through the axial hole in the plunger, it is possible to move the working medium in the direction from the channel F to the channel D with the spring compressed and the displaced position of the spool towards the channel D.

EFFECT: technical result is to improve the reliability of the non-return valve operation.

1 cl, 6 dwg