Safety Valve Calibration and Test Procedure
Safety valves are an important component of many industrial processes, acting as an emergency relief device to prevent overpressure from leading to explosion or other catastrophes. In order to ensure the effectiveness of safety valves, it is necessary to maintain and calibrate the valves on a regular basis. This document describes the calibration and testing procedure for pilot-operated safety valves.
The first step in the Valve Calibration and Test Procedure is to prepare the safety valve for testing by conducting a visual inspection. This should include an examination of the valve stem and stem seal for signs of leakage and visual inspection of the valve disc for signs of damage. Additionally, any connections to the valve should be inspected for signs of corrosion or other damage.
Once the valve has been inspected, the next step is to conduct a leak test to identify any leaks present. This can be done by applying air pressure to the valve and monitoring the pressure gauge. If a leak is detected, the valve should be adjusted or repaired before performing the calibration and test procedure.
The next step in the Valve Calibration and Test Procedure is to check the opening and closing pressures of the safety valve. This should be done in two stages. The first stage is to check the static opening pressure and static closing pressure. To do this, the valve should be opened then pressurized to the desired static opening pressure. The pressure should be checked with a calibrated pressure gauge and then the valve should be actuated with a partial close to the desired static closing pressure. Once the static pressures have been evaluated, the next stage is to check the dynamic opening and closing pressures. This should be done by simulating a process loading and unloading cycle and monitoring the valves response.
Once the opening and closing pressures have been verified, then the safety valve should be tested for proper operation. This can be done by connecting the valve to a calibrated source and actuating the valve with the signal. The valve should open and close as expected.
Finally, the static and dynamic pressures, operation, and leakage should be recorded and the valve should be close for the rest of the test procedure. The valve should then be re-calibrated as needed, and the valve can be certified for use in production.
The Valve Calibration and Test Procedure is an important part of ensuring the safety and reliability of industrial process control systems. By performing this routine inspection, users can ensure that their safety valves are functioning properly and that their process is safe for operation. With careful calibration and testing, users can minimize the risk of overpressure events occurring and prevent potential catastrophes.
