Hazards of abnormal pressure increase in gate valves

The formation of abnormal pressure rise occurs surprisingly similarly in many gate valve applications, as the two major factors involved are similar in many industrial systems, namely, the system medium changes from cold to hot after startup; The ram is closed in the cold state and opened in the hot state. Therefore, if measures are not taken for the system, the damage caused by abnormal boosting to the system is almost inevitable, and it has three hazards:

(1) The strength of the valve casing, valve cover, and valve stem parts is generally designed based on the nominal pressure of the valve. When abnormal pressure is raised, the opening pressure will increase exponentially, resulting in a doubling of the service stress of the relevant parts. When the actual stress of the material exceeds the allowable stress, the high stress parts will fracture and damage, causing the valve to fail to open, and the entire valve will be damaged or scrapped.

(2) The damage to system safety is obvious. When the pressure bearing components such as the shell and valve cover are overpressure, it is very dangerous. Once overpressure occurs, the weak parts may first undergo perforation, causing medium leakage; The packing and self sealing ring parts are often washed out by high-pressure fluid, causing a large amount of media leakage. When the medium is high-temperature gas, toxic gas, or harmful gas, it can become even more serious, and even cause damage to equipment and personnel.

(3) The normal opening and closing of valves is the key to controlling various industrial processes, causing significant losses to the production control process. Once this control cannot be achieved, the system will be shut down for maintenance, which will result in significant direct or indirect losses