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Improper selection or use of safety valves can lead to valve failures. If these faults are not resolved in a timely manner, they will affect the performance and lifespan of the valve, and it may even fail to provide any safety protection. 1. Common faults include: (1) Valve leakage. (2) The valve does not open and close smoothly or crisply. (3) The opening pressure value is inaccurate. (4) Valve oscillation or frequency hopping. 2. Valve leakage: This refers to a leakage at the seal surface between the valve disc and the valve seat that occurs at the normal operating pressure of the equipment, and exceeds the allowable level. The reason may be: (1) The stolen goods fell on the sealing surface. A lift wrench can be used to open the valve several times in order to flush out the debris. (2) Damage to the sealing surface. Repair should be carried out by grinding or by grinding after turning, depending on the degree of damage. (3) If the coaxiality of the parts is compromised due to improper assembly or pipeline loads, reassembly or removal of the additional pipeline loads is required. (4) The valve opening pressure is too close to the normal operating pressure of the equipment, resulting in insufficient pressure on the sealing surface. Leaks are more likely to occur when the valve is subjected to vibrations or fluctuations in medium pressure; therefore, the opening pressure should be adjusted appropriately based on the strength requirements of the equipment. (5) Spring relaxation reduces the set pressure and causes valve leakage. It may be caused by high temperatures or corrosion, etc.; measures such as replacing the spring or even swapping the valve (if it was improperly selected) should be taken depending on the cause. If it is caused solely by improper adjustment, simply tighten the adjustment screw properly. 3. The valve does not open and close smoothly or crisply; the main reason for this may be: (1) Improper adjustment of the adjusting ring, which results in a prolonged opening process or slow closing, and it should be adjusted again. (2) There is jamming in the internal moving parts; this may be caused by improper assembly, contamination, or part corrosion. The cause should be identified and eliminated. (3) The resistance in the discharge pipe is too high; a significant backpressure builds up during discharge, preventing the valve from opening fully. Resistance to emissions management should be reduced. 4. Variation in set pressure: After the safety valve is adjusted, a certain deviation between its actual opening pressure and the set value is permissible. Any value that falls outside the allowable tolerance range specified by the standards is considered abnormal. The reasons for changes in the opening pressure value may include: (1) Caused by changes in operating temperature. For example, when a valve is adjusted at normal temperature and used at high temperatures, its opening pressure often decreases. This can be adjusted by properly tightening the adjusting screw. However, if the excessive temperature in the spring chamber is caused by an inappropriate selection, then a suitable model should be used (for example, one with a radiator). (2) Caused by spring corrosion. The spring should be replaced. In situations where the medium is highly corrosive, springs with fluoroplastic coatings on their surfaces or safety valves equipped with bellows isolation mechanisms should be used. (3) Caused by changes in back pressure. When the change in back pressure is significant, a back-pressure balanced bellows safety valve should be selected. (4) There is jamming in the internal moving parts. It should be checked and eliminated. 5. Valve oscillation or frequency hopping. The possible reasons are as follows: (1) The valve’s discharge capacity is too high (compared to the required discharge volume). The rated discharge capacity of the valve selected should be as close as possible to the required discharge volume of the equipment. (2) The diameter of the inlet pipe is too small or the resistance is too high. The inner diameter of the inlet pipe should be no smaller than the valve’s inlet diameter, or the resistance in the inlet pipe should be reduced. (3) Excessive resistance in the discharge pipeline results in high back pressure during discharge. The resistance of the exhaust pipeline should be reduced. (4) The adjustment ring is not set properly, resulting in excessive reseating pressure. The position of the adjustment ring should be readjusted. (5) The spring stiffness is too high. Springs with lower stiffness should be used instead.