| 摘要 |
<p>A double sealed valve according to the invention includes a valve seat 6 in a communicating passage 3 formed between an upper passage 1 and a lower passage 2. The valve also includes a first vertical valve stem 8 and a second vertical valve stem 10, which is hollow and slidably surround the first stem 8. The first stem 8 has a first valve plug 7 for slidable engagement with an inner peripheral side of the seat 6. The second stem 10 has a second valve plug 9 for compressive engagement with an upper side of the seat 6. The first stem 8 is connected to a valve drive mechanism 28. When the valve opens, the drive 28 lifts the first stem 8, with which the second plug 9 moves upward. <IMAGE></p> |
