Patent ID: 6835053
Filing Date: 2004-12-28
Classification: F04B,F16K,Y10T

Abstract:
A check valve for permitting fluid to flow in one direction in a fluid passage comprising:a valve seat member having an inner wall that forms the fluid passage, the inner wall being provided with immediately adjacent first and second conical seats and the second conical seat being positioned upstream the first conical seat; and a valve member being provided at an outer circumference thereof with a conical face that comes in contact with the first conical seat for closing the fluid passage and away therefrom for opening the fluid passage, wherein an angle of the second conical seat to an axis of the valve member is more acute than that of the first conical seat, and a seat angle of the conical face of the valve member to the axis is larger than the angles of the first and second conical seats to the axis of the valve member, wherein a circumferential boundary between the first and second conical seats is formed at such a place where a distance of the circumferential boundary to the axis of the valve member is between the minimum and maximum distances of the conical face to the axis of the valve member so that the boundary may come in contact with the conical face of the valve member after the first conical seat and the conical face become worn.