Problems with the use of safety valves
Thread Content
The new safety valve passed the calibration, but it started to operate abnormally and experienced internal leakage after being installed in the pipeline or equipment and operated for some time. They were removed and tested on the testing bench to check for any omissions. What exactly is the reason for the slightly positive pressure at the outlet of the safety valve? Was it because the manufacturer didn’t conduct the relevant type tests at the time of production? ? ? ? ? ? ?
Has the strength decreased due to use in high-temperature environments?
Another possibility is that the pressure gauge on the safety valve calibration bench has not been calibrated, resulting in inaccurate test pressures.
I didn’t pay attention to that point you mentioned; I’ll keep an eye on it next time
First, check whether the calibration is correct, and then examine the operating environment, such as temperature, pressure, and operational stability.
The environment is different from the operating environment, especially as it is greatly affected by pressure and temperature
The medium is always at a temperature of 50–300°C, but the pressure isn’t high; it’s around 3.4 MPa at most. It is Lei Ren Er, Dalian Guoan, and Luofu that experience frequent leaks (50% of the safety valves in these units have such problems). What could be the reason for this? Did the safety valve manufacturer fail to conduct the type test? There must be other reasons
It could be a manufacturing quality issue; you can contact the manufacturer to resolve it.
Testing safety valves on a testing bench involves cold-state testing, which is different from the operating conditions under which the valves are used in equipment; for example, the temperature in the equipment might be quite high. Situations like the one you mentioned can occur, and the solution is to conduct an online verification.
What is the method for online verification? Is it necessary for the safety valve to activate? We tried online verification, but just checking the values did not serve the purpose of verification.