| 摘要 |
<p>An apparatus, an assembly and a method for selectively cutting off a fluid flow in a pipe are disclosed. The assembly includes a hollow body (10) comprising a main chamber (32) and a control chamber (34) communicating via a first calibrated port (8), first connecting means (2), a fluid supply pipe (6) comprising two concentric channels (6a, 6b) communicating with the main (32) and control (34) chambers, a membrane (12) arranged in the control chamber (34) and acted upon by pressure means (14), a second sealable port (4) through which the fluid flows, and a closure valve (16) operably connected to the membrane (12) sealing the second port (4) when the fluid pressure in the control chamber (34) is not within a predetermined range.</p> |
