摘要 |
<p>Apparatus for detecting a rate of pressure rise in a pipeline higher than an acceptable level, comprising a monitor conduit which is connected between the pipeline and a monitor chamber of uniform cross-section with a spring-biased piston or diaphragm therein. The invention contemplates means for producing a signal proportionate to the flow through said monitor conduit and, hence, to the rate of pressure change in the pipeline. One embodiment includes a device which senses the difference in pressure between the pipeline and the monitor chamber and delivers a signal when that difference becomes excessive. In another embodiment, a liquid reservoir at atmospheric pressure is connected to fill the monitor chamber on the other side of the diaphragm, so that the liquid pressure in the monitor chamber is proportionate to the rate of change of pressure in the pipeline and, when this pressure becomes excessive, an energizing signal is generated to relieve the surge.</p> |