Analysis of the reasons for the operation of the pressure controller and the activation of the safety valve

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The main reason that causes the high-pressure pressure controller to activate is: (1) the high-pressure exhaust pressure of the compressor exceeds the set value of the pressure controller. (2) The compressor stops operating due to malfunction caused by the spring mass of the high-pressure pressure controller. (3) Due to quality issues with the microswitch of the high-pressure pressure controller, the microswitch changes from a closed state during normal operation to an open state, causing the compressor to stop running. The main reason for the safety valve to activate is: (1) the exhaust pressure of the compressor is higher than the activation threshold of the safety valve. (2) Due to quality issues with the pressure spring of the safety valve, the safety valve activated before the exhaust pressure reached its set value. In addition to a safety valve, a pressure controller is also installed in the refrigeration system. According to the specifications, the operating pressure of the pressure controller should be lower than the setting pressure of the safety valve. In other words, when a pressure overload fault occurs, it should be the pressure controller that takes action first by cutting off the power to the compressor; once the compressor stops operating, the system pressure will no longer rise. Therefore, the activation of the safety valve generally indicates a fault in the pressure controller. After dealing with the safety valve tripping, the pressure controller should be inspected. The safety valve is the final technical safeguard for controlling equipment pressure; when the safety valve activates, it is absolutely not allowed to use the shut-off valve located below it in order to prevent the safety valve from releasing pressure. An emergency shutdown must be carried out, following these procedures: (1) Immediately cut off the power supply to the compressor, and close its suction valve and exhaust valve. (2) Continue to operate the cooling water system to rapidly reduce the pressure within it, and then shut down the cold water system. (3) After the safety valve closes automatically, conduct the corresponding inspections and repairs. (4) Fill in the fault details, occurrence time, and handling results in the shift handover record and operation record.