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Spring-loaded safety valve works
Nov 23, 2017

Spring type safety valve to rely on elastic pressure spring and the seal valve closed valves or plunger, high pressure when the pressure of pressure vessels after abnormal will generate over the spring pressure safety valve, so the locking device is to open the top, forming a pressure relief channel, the high voltage discharge.

According to the opening height of the valve opening, it can be divided into two types: full lifting and micro lifting. It is suitable for liquid and gas medium, and micro lifting is only suitable for liquid medium.

According to the analysis of spring safety valve opening characteristics, it can be concluded that under the action of external force FW, a safety valve from closing to opening, and then from opening to closing of the whole process.

In this process, changes of external force FW, when the additional force gradually increased from zero, and the pressure in the PL * S and just as the spring preload, the valve opening slightly, increases the role of the media area S, the sharp increase of force to overcome the spring preload pressure within the this results in a reduced additional external force at the moment. Thus the first characteristic peak A appears.

When the external force decreases gradually and reaches the closing point, because of the sudden decrease of the acting area of the medium, in order to maintain the balance relationship of force, at the same time, the additional force will appear instantaneous recovery phenomenon, namely second characteristic peak point B. The above two characteristic peak points A and B are the technical basis for detecting the opening pressure and the seat pressure of the safety valve under the condition of online.