| 摘要 |
<p>To prevent leaks through the valve in the closed position, it comprises zones (5A, 5B) ensuring respectively the leaktightness of the obturation of each of the first and second passages (2A, 2B), and also a chamber (6) arranged in this position between the said zones, which is provided with an orifice (7) opening to the outside, so as to communicate with the atmosphere and to discharge any leaks from the said leaktight zones. …<??>In order to produce a fluid actuating device or a backflow preventer, the valve is associated with non-return valve members and/or a vacuum breaker and/or a system for the automatic control of the obturator. …<IMAGE>… </p> |
