How to adjust and verify the safety valve?

Safety valves should be adjusted and verified before use.

(1) Pressure relief test and airtightness test shall be conducted before safety valve is installed to check the strength and sealing performance of safety valve. Only after passing the calibration and adjustment.

(2) On the gas test bench, the opening pressure of the safety valve is corrected by adjusting the load applied to the disc. The lever-type safety valve adjusts the position of the weight, and the spring-loaded safety valve regulates the compression of the spring. The opening pressure of the safety valve shall comply with the relevant provisions of the supervision regulations for boiler and pressure vessel safety technology.

(3) In the container, the discharge pressure and return pressure of the safety valve are adjusted by adjusting the clearance between the safety valve adjusting ring and the valve disc. If the safety valve only leaks under the opening pressure and does not jump or jump, but there is severe vibration and "buzzing" sound after the pressure drops, the clearance is too large and should be adjusted to be smaller. If the pressure on the seat is too low, the clearance of the adjusting ring is too small and it should be adjusted appropriately. The discharge pressure of the steam safety valve shall be less than or equal to 1.03 times the opening pressure, and the opening and closing pressure shall not exceed 10% of the opening pressure. The discharge pressure of the safety valve for air or other gas should be less than or equal to 1.10 times the opening pressure, and the opening and closing pressure should not exceed 15% of the opening pressure.

(4) When the safety valve is used for calibration and pressure adjustment, technical personnel using the safety of the unit's main boiler pressure vessel must be present. The accuracy of the pressure gauge for the adjustment and calibration device should not be lower than Class 1. When on-line calibration, There are safety precautions.

(5) During the verification process, the verification personnel should make timely records. The qualified safety valve shall be sealed after installation of the relevant accessory device to prevent any changes to the adjusted state.