| 摘要 |
PURPOSE:To prevent leakage of flowing fluid having a high temperature and a high pressure and permit certain operation of a ball valve by supplying the fluid for seal which has the higher pressure than that of the fluid which flows in the ball valve, into the sealed space between the valve piece and the ball of the ball valve. CONSTITUTION:The pipes 5, 7, and 8 which are equipped with auxiliary valves 9 and 10 are connected to the sealed space 1a between the valve piece 1 and the ball 2 of a ball valve, and the fluid for seal which has the higher pressure than that of the fluid which flows in the ball valve is supplied into the sealed space 1a. Therefore, when the valve is closed, a seat 3 installed in the sealed space 1a is pressed by the sealing surface of the ball valve, and the sealing effect is improved, and leak is not generated. While, when the ball valve is opened, the fluid supplied into the sealed space 1a is discharged, and the pressing force applied onto the seat 3 is reduced, and thus the valve opening operation can be executed smootyly and certainly. |
