Check valve assembly (1, 1) for a shock absorber (100) comprising a housing (10), said housing (10) comprising a first volume (11), wherein a first pressure (P1) prevails; a second volume (12), wherein a second pressure (P2) prevails; a fluid passage (20) between said first (11) volume and said second (12) volume; and a spool (40) movably arranged in said housing (10) for movement back and forth between an first position, in which a flow of fluid through said fluid passage (20) is allowed, and a second position, in which the spool (40) closes the fluid passage (20). The check valve assembly further comprises a first biasing means (50) configured to bias the spool (40) towards the second position through at least first operational range (OR1) of the spool (40) in which first operational range the fluid passage (20) is open. Also, the check valve assembly comprises a second biasing means (51) configured to bias the spool (40) towards the first position partly through a second operational range (OR2) of the spool (40) in which second operational range (OR2) the fluid passage (20) is closed. The first biasing means forces the spool from its open position at least to its closed position for closing the passage.

Check valve assembly (1, 1) for a shock absorber (100) comprising a housing (10), said housing (10) comprising a first volume (11), wherein a first pressure (P1) prevails; a second volume (12), wherein a second pressure (P2) prevails; a fluid passage (20) between said first (11) volume and said second (12) volume; and a spool (40) movably arranged in said housing (10) for movement back and forth between an first position, in which a flow of fluid through said fluid passage (20) is allowed, and a second position, in which the spool (40) closes the fluid passage (20). The check valve assembly further comprises a first biasing means (50) configured to bias the spool (40) towards the second position through at least first operational range (OR1) of the spool (40) in which first operational range the fluid passage (20) is open. Also, the check valve assembly comprises a second biasing means (51) configured to bias the spool (40) towards the first position partly through a second operational range (OR2) of the spool (40) in which second operational range (OR2) the fluid passage (20) is closed. The first biasing means forces the spool from its open position at least to its closed position for closing the passage.

An annular valve in which the shape of a sealing surface of a valve body is optimized thus suppressing the occurrence of pressure loss in gas on the periphery of the sealing surface and extending the service life of the annular valve. The annular valve comprises: a valve seat 10 formed in a plate-like shape and including passage flow channels 11 each having an opening cross section formed in an arcuate shape; a receiving plate 20 formed in a plate-like shape and having discharge flow channels 21, the receiving plate 20 being arranged to face the valve seat 10 by way of an intermediate chamber 50; a valve body 30 formed in an annular shape corresponding to the arcuate shape of the opening cross section of the passage flow channel 11 and being arranged in the intermediate chamber 50, the valve body 30 being brought into contact with/separated from the valve seat 10 so as to open/close the passage flow channel 11; and a plurality of spring members 40 supported by the receiving plate 20, the spring members 40 each biasing elastically the valve body 30 toward the valve seat 10. A sealing surface 31 of the valve body 30 that faces the passage flow channel 11 is formed in a shape where at least one of pressure loss elements with respect to gas flowing towards the valve body 30 from the passage flow channel 11 is eliminated.

A nozzle check valve comprises a valve body (10) and a nozzle (20) centrally arranged within the upstream end of valve body (10), a fluid channel (90) is defined by the outer face of the nozzle (20) and the inner face of the valve body (10). A guide bush (60) is mounted on a nozzle axial extension (26) and an annular disc (30) comprising a disc sealing ring (31) connected to a central barrel (32,33) by a plurality of webs (34) is mounted on the guide bush (60) for axial movement of the annular disc (30) relative to the valve body to open and close the fluid channel (90). A spacer (80) is arranged on the nozzle axial extension (26) downstream of the guide bush (60) and a diffuser (40) is arranged on the downstream side of the spacer (80). A spring (50) between the annular disc (30) and the diffuser (40) urges the disc towards the valve closed position. The stroke of the valve, the maximum movement of the annular disc (30) from the valve closed position to the valve open position where the annular disc (30) is in contact with the upstream face of the diffuser (40), is determined by the axial length of the spacer (80). The centre of mass of the annular disc (30) is located along the central axis of the disc (30) at an axial position where the barrel (32) is in sliding contact with the guide bush (60).

A nozzle check valve comprises a valve body (10) and a nozzle (20) centrally arranged within the upstream end of valve body (10), a fluid channel (90) is defined by the outer face of the nozzle (20) and the inner face of the valve body (10). A guide bush (60) is mounted on a nozzle axial extension (26) and an annular disc (30) comprising a disc sealing ring (31) connected to a central barrel (32,33) by a plurality of webs (34) is mounted on the guide bush (60) for axial movement of the annular disc (30) relative to the valve body to open and close the fluid channel (90). A spacer (80) is arranged on the nozzle axial extension (26) downstream of the guide bush (60) and a diffuser (40) is arranged on the downstream side of the spacer (80). A spring (50) between the annular disc (30) and the diffuser (40) urges the disc towards the valve closed position. The stroke of the valve, the maximum movement of the annular disc (30) from the valve closed position to the valve open position where the annular disc (30) is in contact with the upstream face of the diffuser (40), is determined by the axial length of the spacer (80). The centre of mass of the annular disc (30) is located along the central axis of the disc (30) at an axial position where the barrel (32) is in sliding contact with the guide bush (60).

A check valve which allows a sub valve body to have an improved sealing function when the check valve has an increased size. When a sub valve body 300 is seated on a second valve seat 231 and a third valve seat 440, S21 is satisfied where a seal area S1 is a total of a contact area of the sub valve body 300 and the second valve seat 231 and a contact area of the sub valve body 300 and the third valve seat 440, and a pressure-receiving area S2 is an area of a non-contact region at a lower end surface of the sub valve body 300 between a contact region of the sub valve body 300 and the second valve seat 231 and a contact region of the sub valve body 300 and the third valve seat 440.

An automatic back-pressure valve is for use in a supercritical fluid chromatographic system, consisting of: a spring support (1); an ejector rod spring (2); an ejector rod (3); a piston rod (4); a guide band (5); a cylinder body (6); an O-ring seal ring A (7); an O-ring seal ring B (8); a piston rod spring (9); a cylinder cover (10); a guide sleeve (11); a conical ceramic element (12); a seal ring (13); a sealing base (14); a valve body (15); a screw (16); and a positioning sleeve (17).

An automatic back-pressure valve is for use in a supercritical fluid chromatographic system, consisting of: a spring support (1); an ejector rod spring (2); an ejector rod (3); a piston rod (4); a guide band (5); a cylinder body (6); an O-ring seal ring A (7); an O-ring seal ring B (8); a piston rod spring (9); a cylinder cover (10); a guide sleeve (11); a conical ceramic element (12); a seal ring (13); a sealing base (14); a valve body (15); a screw (16); and a positioning sleeve (17).

Embodiments of the present disclosure provide a flow control valve, an oil pump assembly having the flow control valve, and a scroll compressor. The flow control valve includes: a valve body having an inlet configured for a fluid to flow into the valve body and an outlet configured for the fluid to flow out of the valve body; a passage provided between the inlet and the outlet and extending in a predetermined direction, an area of a cross section of the passage perpendicular to the predetermined direction being negatively correlated with a distance from the cross section to the inlet; a valve element slidably provided in the passage, a flow area between the valve element and an inner wall of the passage is negatively correlated with the distance from the valve element to the inlet; and an elastic member provided in the valve body to apply an elastic force on the valve element so as to move the valve element in a direction toward the inlet. Thereby, for example, lubrication of the scroll compressor is improved.

Embodiments of the present disclosure provide a flow control valve, an oil pump assembly having the flow control valve, and a scroll compressor. The flow control valve includes: a valve body having an inlet configured for a fluid to flow into the valve body and an outlet configured for the fluid to flow out of the valve body; a passage provided between the inlet and the outlet and extending in a predetermined direction, an area of a cross section of the passage perpendicular to the predetermined direction being negatively correlated with a distance from the cross section to the inlet; a valve element slidably provided in the passage, a flow area between the valve element and an inner wall of the passage is negatively correlated with the distance from the valve element to the inlet; and an elastic member provided in the valve body to apply an elastic force on the valve element so as to move the valve element in a direction toward the inlet. Thereby, for example, lubrication of the scroll compressor is improved.