Patent ID: 6910745

Claim:
A check valve comprising: a case member in which a fluid path is formed, and an opening, which is located in the fluid path, is formed in the case member; a valve seat surface, which is formed in the case member and disposed in the middle of the fluid path; a valve body which is disposed downstream of the valve seat surface in the fluid path and opens and closes the fluid path by seating on and separating from the valve seat surface; and a helical compression spring which is disposed in the case member and urges the valve body in a valve closing direction, wherein: a side wall surface and a spring receiving surface are formed in the case member; the side wall surface restricts a movement area of the valve body in a direction perpendicular to a pressure action direction, wherein the pressure action direction is defined as a direction in which a pressure of a fluid upstream of the valve seat surface acts; the spring receiving surface buts with one end of the helical compression spring; and the spring receiving surface is inclined with respect to a plane that is perpendicular to the pressure action direction so that a perpendicular component of a force applied to the valve body by the helical compression spring is applied generally toward the opening, wherein the perpendicular component is perpendicular to the pressure action direction.