安全阀校验 Main Contents of Safety Valve Calibration

安全阀校验的主要内容包括：

1. ‌开启压力校验‌：检测安全阀在设定压力下是否能够准确开启。通常使用压力试验台进行测试，通过逐步增加压力，观察阀瓣的开启情况。开启压力应符合设计要求，误差范围一般在±3%以内。
2. ‌密封性能校验‌：检测安全阀在关闭状态下的密封性能。通过加压至设定压力的90%，观察是否有泄漏现象。密封性能良好的安全阀应无可见泄漏。
3. ‌回座压力校验‌：检测安全阀在压力下降时是否能够及时回座。回座压力通常为开启压力的80%-90%，具体数值需根据设备要求确定。

安全阀校验的常见方法包括：

• ‌离线校验‌：将安全阀从设备上拆卸下来，送至专业校验机构进行检测。这种方法适用于定期校验或新安装的安全阀。
• ‌在线校验‌：通过专用设备在不拆卸安全阀的情况下进行校验。这种方法适用于运行中的设备。

安全阀校验的频率应根据设备的使用环境和工况确定。一般建议每年至少进行一次校验，对于高温、高压或腐蚀性介质环境中的安全阀，校验频率应适当提高。

校验过程中需注意以下事项：

1. ‌安全防护‌：校验时应确保设备处于安全状态，避免超压或泄漏风险。
2. ‌环境条件‌：校验环境应保持清洁，避免灰尘或杂质影响校验结果。
3. ‌记录保存‌：校验完成后应详细记录各项参数，并存档备查。

The primary calibration procedures for safety valves include:

1. Opening Pressure Calibration  

This verifies whether the safety valve accurately opens at the set pressure. Typically performed using a pressure test bench, the pressure is gradually increased to observe the valve disc's opening behavior. The opening pressure must comply with design requirements, with a typical allowable error margin of ±3% or less.

2. Sealing Performance Calibration  

This assesses the sealing capability of the safety valve in the closed state. The valve is pressurized to 90% of the set pressure, and any leakage is monitored. A properly sealed safety valve should exhibit no visible leakage.

3. Reseating Pressure Calibration  

This checks whether the safety valve reseats promptly as pressure decreases. The reseating pressure is generally between 80% to 90% of the opening pressure, with specific values determined based on equipment requirements.

Common Methods for Safety Valve Calibration

- Offline Calibration

The safety valve is removed from the equipment and sent to a specialized calibration facility. This method is suitable for periodic calibration or newly installed safety valves.

- Online Calibration  

Performed using specialized equipment without disassembling the safety valve. This approach is applicable to equipment in operation.

Calibration Frequency

The calibration frequency should be determined according to the equipment's operating environment and conditions. Generally, it is recommended to conduct calibration at least once a year. For safety valves in high-temperature, high-pressure, or corrosive media environments, the frequency should be appropriately increased.

Key Considerations During Calibration

- Safety Precautions  

Ensure the equipment is in a safe state during calibration to avoid risks of overpressure or leakage.

- Environmental Conditions  

Maintain a clean calibration environment to prevent dust or impurities from affecting the calibration results.

- Record Keeping  

After calibration, all parameters should be documented in detail and archived for future reference.