| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an apparatus capable of reducing the friction of a seal at high temperatures, thereby reducing the amount of actuation thrust required to throttle the valve.SOLUTION: An apparatus includes: a cage 13; and a main plug 15 disposed in the cage 13. The main plug 15 is movable between a main plug closed position and a main plug open position. A seal assembly 46 is disposed on the main plug 15, the seal assembly 46 having a seal 47 that is configured to contact the cage 13 when the main plug 15 is in the main plug closed position, and configured to reduce contact with the cage 13 when a pressure differential across the seal 47 is reduced. The apparatus includes a pressure balancing assembly 31 movable between a closed position, an overtravel position and an open position. The pressure balancing assembly 31 is configured to balance the pressure differential across the seal 47 when in the overtravel and open position.</p> |
