| 摘要 |
The present invention relates to a processing tool or a forging process valve seat, and more specifically, to a processing tool to form a first tube expansion part and a second tube expansion part, which have each different diameter, on a contact surface of a valve seat, which is in contact with a ball, in manufacturing a R-valve. The first tube expansion part and the second tube expansion part are easily formed on the contact surface such that the contact surface of the valve seat is altered to correspond to the outer circumference of the ball when the ball presses and is in contact with the contact surface, thereby previously preventing a leak of the contact surface between the ball and the valve seat. |
