| 摘要 |
<p>An apparatus for controlling flow in a flowline under pressure, said apparat us comprising a flow passage having a first end and a second end, and hindering means for reducing the flow in the flow passage, the hindering means being arranged to move between a first and a second position under influence of a pressure difference between the first end and the second end of the flow passage. The reduction of the flow in the flow passage is larger when the hindering means is in the first and second position than when the hindering means is in an intermediate position between said first and second positions . Hereby an improved safety valve, which is adapted to shut off flow in a flow line in two directions, is provided.</p> |
