Due to improper assembly or installation of the control valve pipeline, various stresses will occur, such as thermal stress caused by high temperature medium, stress caused by unbalanced tightening force during installation, stress caused by some man-made collisions on the control valve and its pipeline, etc. These stresses can easily affect the performance of the control valve and its pipeline, and seriously affect the control system itself, leading to the deformation of the stem and guide parts and not aligning with the seat; for the split valve body, the control valve may cause the valve body flange to detach; and the stress may also cause the seat leakage. And so on. Therefore, stress should be avoided or eliminated at all times, and the stress should be directed away from the control valve.
The safety operation of the control valve and its accessories used in explosive dangerous places should be checked, such as tightening of the sealing cover, operation of the safety grate, power supply, etc. to ensure the safe operation of the control valve and related accessories.
Source: Baidu Encyclopedia