Analysis of opening action characteristics of Globe Valve

Globe Valve are divided into full-lift type and micro-lift type according to the different opening heights of the valve disc. They rely on the elastic pressure of the spring to lock the valve's valve flap or plunger and other seals. Once the pressure of the Pressure Vessel is abnormal, a Globe Valve will occur. The high pressure will overcome the spring pressure of the Globe Valve, so the locking device is pushed open, forming a pressure relief channel to release the high pressure. The full-lift type has a large discharge capacity and good resilience, and is suitable for liquid and gas media, while the micro-lift type is only suitable for liquid media.

Under the action of the external force FW, during the entire process of a Globe Valve from closing to opening, and then from opening to closing, the changing pattern of the external force FW, when the additional force gradually increases from zero, is the sum of the internal pressure PL×S When the spring preload is exactly the same, the valve opens slightly, which increases the medium action area S, causing the internal pressure force used to overcome the spring preload to increase sharply. As a result, the external additional force is instantly reduced. Thus the first characteristic peak A appears.
When the external force gradually decreases and reaches the closing point, due to the sudden reduction of the medium's action area, in order to maintain the balance relationship of the force, at this time, the external force will rise instantaneously, that is, the second characteristic peak point B.