Working principle, characteristics, and operating steps of switchable safety valve

Safety valves are widely used in various industries of the national economy as safety accessories for boilers, pressure vessels, and pipelines. According to the national "Safety Technical Supervision Regulations for Pressure Vessels", "safety valves should generally be calibrated at least once a year". However, it is difficult to achieve annual calibration for the continuous operation of equipment in petrochemical, chemical and other enterprises for more than one year, even two or three years; Some devices operate continuously without maintenance periods; In addition, it is also difficult to achieve disassembly and replacement without stopping the machine when the safety valve on the operating device malfunctions. For this purpose, a rapid switching device for safety valves has been developed, which can achieve the goal of quickly replacing safety valves without stopping the machine.

The main characteristics of a switchable safety valve are: 1. Three way flow path design, where two identical safety valves are installed at one workstation, one of which is used for online overpressure protection and the other is used as a maintenance backup. 2. The reversing system is safe, easy, and fast to operate. 3. Quick switching without the need for device parking, providing continuous overpressure protection to avoid expensive losses caused by emergency parking maintenance. 4. Below each safety valve, there is a relief valve installed to safely and effectively release the medium before the safety valve is disassembled, and introduce it into the discharge pipe. 5. The quick switching device is equipped with a balance valve, making it easy to operate. 6. Wide applicable temperature range (from low temperature to high temperature). 7. Reliable sealing, maintaining the required sealing even after multiple actions.

The operation steps of the switchable safety valve are as follows: 1. Check the two relief valves to ensure they are in the closed state. 2. Open the balance valve. 3. Rotate the handwheel to complete the switch. 4. Close the balance valve. 5. Open the relief valve in the standby position to drain the medium in front of the safety valve on this side. 6. Remove the spare safety valve that needs maintenance or replacement.