| 摘要 |
<p>A double seal valve 1 and methods for monitoring leakage past the seals are disclosed. The valve has two chambers 6, 8 joined by an intermediate passage 18 and is selectively configurable in three separate configurations. In the first configuration the intermediate passage is open, in a second 'closed' configuration the intermediate passage is closed by first 24 and second 26 seals seated at respective locations in the passage to create a leakage chamber 28 between the seals. In a third 'cleaning' configuration one of the two seals is unseated to connect one of the two valve chambers to the leakage chamber. A flow sensor 3 is connected to the leakage chamber to provide a signal indicative of a leakage flow from the leakage chamber.</p> |
