Maintenance and Inspection of Safety Valves

To ensure the safety valve operates sensitively, reliably, and maintains good sealing performance, it is essential to enhance maintenance and inspection during the operation of boilers, pressure vessels, and pressure pipelines.

(1) Maintain the cleanliness of the safety valve regularly to prevent the valve body spring and other components from being clogged with oil stains or corroded, and to avoid blockage of the safety valve discharge pipe by oil or other foreign substances. Frequently inspect the integrity of the lead seal to prevent loosening or displacement of the weight in lever-type safety valves, as well as unauthorized adjustments.

(2) If signs of leakage are detected in the safety valve, it should be promptly replaced or repaired. It is prohibited to eliminate leakage by increasing the load (e.g., excessively tightening the adjustment screw of a spring-type safety valve or adding weights to the lever of a lever-type safety valve). To prevent the valve disc and seat from being stuck by contaminants such as oil deposits in the gas, which could prevent the safety valve from opening properly, manual discharge tests should be conducted regularly for safety valves used in air, steam, or other gases containing viscous contaminants but where discharge would not cause harm.

(3) To ensure the safety valve remains sensitive and reliable, a periodic calibration must be conducted at least once a year. The calibration typically includes dynamic testing and disassembly inspection. Dynamic testing primarily involves checking the valve's opening pressure, closing pressure, sealing performance, and lift height under rated discharge pressure, with requirements identical to those during safety valve commissioning. If dynamic testing fails or abnormal conditions such as leakage are detected during operation, disassembly inspection is required. After disassembly, all components of the safety valve should be carefully examined for cracks, scars, wear, corrosion, deformation, or other damages. Repairs or replacements should be made based on the severity and extent of defects, followed by reassembly and another round of dynamic testing.

Special equipment user units must attach great importance to the troubleshooting, maintenance, and inspection (servicing) of safety valves, as well as the lessons from related accidents and the critical role of safety valves in pressure-bearing special equipment. Special equipment manufacturers and user units, especially small and medium-sized private enterprises, should diligently study and implement the "Special Equipment Safety Supervision Regulations," strictly adhere to safety operating procedures and regulations. In addition to conducting regular daily maintenance and inspections of the pressure-bearing special equipment itself, they must also perform periodic calibration and servicing of its safety accessories in accordance with regulations, incorporate these measures into special equipment safety management, promptly address identified hazards, eliminate risks, and genuinely assume corporate responsibility to ensure the safe operation of special equipment.