Safety valve calibration has two methods of on-site calibration (online calibration) and calibration table calibration. If conditions permit, it should be calibrated in the field as far as possible, because the on-site calibration is more suitable for the actual operating conditions, so it is more reliable.
Advantages and disadvantages of on-site calibration:
(1) it is easy to check the welding safety valve and can measure the return pressure.
(2) the disadvantage is that the calibration time is long, the system should be repeatedly boosted, uneconomical, more dangerous, can not be done sealing test.
The advantages and disadvantages of the normal temperature check table of the safety valve:
(1) solve the normal temperature medium and operating temperature below 250℃ safety valve setting and leak detection.
(2) determine the small error range of the opening pressure of the safety valve, save the adjustment time of the newly installed safety valve, reduce the labor intensity, reduce energy consumption and reduce the risk of work.
(3) the disadvantage is that there is an error between the operating temperature and the normal temperature (the spring becomes soft at high temperature), and the return seat pressure cannot be verified.