Patent ID: 7950414

Claim:
A regulating check valve for being installed in a fluid passage that communicates a first flow passage to a second flow passage to open or close the fluid passage, the regulating check valve comprising: a valve body having a valve chamber, a first communicating hole that communicates the valve chamber with the first flow passage, a second communicating hole that communicates the valve chamber with the second flow passage and a valve seat that is formed on an inner surface of the valve chamber and surrounds one end of the first communicating hole; a valve element that is slidably installed in the valve chamber, has a seating portion that seats on or lifts away from the valve seat to close or open the first communicating hole, wherein the valve element is urged by a pressure in the first flow passage in a valve-opening direction to lift the seating portion away from the valve seat and is urged by a pressure in the second flow passage in a valve-closing direction to seat the seating portion on the valve seat; and a spring that is interposed between the valve element and the valve body to urge the valve element in the valve-opening direction, wherein: the valve body has an approximately cylindrical shape; the valve seat has an approximately conical shape that is recessed toward the first flow passage; the valve element has a flange portion that protrudes radially outward and is slidably supported by an inner circumferential wall of the valve body; the spring is interposed between the flange portion of the valve element and the valve body; the valve body has an annular groove on the inner circumferential wall; the annular groove is closed by the flange portion when the seating portion is seating on the valve seat and is exposed to the valve chamber when the seating portion is lifting away from the valve seat; and the valve body has a third communicating hole that communicates the annular groove to the second flow passage.