Industry News

Three Methods For Safety Valve Calibration

At present, there are two mainly methods for safety valve testing generally,off-line calibration and online calibration.Regarding to the Offline calibration,the equipment need to stop running and put the Safety Valve to test table for calibration, in this way,it takes much time and labors,and still have influence of temperature on the opening pressure.For online calibration,it has pressurization jumping testing and instrument testing. Today, let us study together their difference.

Firstly is the off-line calibration on test table, install correctly the safety valve on the test table, and under the action of the medium, the safety valve will reach the opening pressure, by observing the pressure gauge to confirm the opening pressure.This ways is not recommended for the back pressure safety valve and high or low temperature medium safety valve for calibration;

Secondly is pressurization jumping method.Install the safety valve in the system, and manual control the system to pressurize until the safety valve jumping ,to confirm the opening pressure value.This method has great damage to the sealing surface of the safety valve and great operation risk;

Thirdly is the online instrument testing,to measure the acting force on the downward spring of the safety valve,to calculate the opening pressure of the safety valve, this method generally does not affect the production,system pressure, the test speed is relatively fast, convenient, but this method can not test the leakage performance of the safety valve.