| 摘要 |
The device has a body (1) having an inlet (2), outlet (3) and a passage. The passage is closed by shutters having conical movable elements (5, 7) cooperating in a sealed manner with respective seats (6, 8). A membrane (12) is integrated with a movable unit (9) to partition an upper part of a low pressure chamber (11). The unit (9) is displaced towards top to displace the elements (5, 7) and to regulate gas flow and work pressure in the chamber. The elements (5, 7) are engaged to permit the element (5) and the seat (6) to be closed before the element (7) and the seat (8). |
