SRV is installed in place that require fast response performance to protect the piping system from the surge(Water hammer) by sudden flow change and pump sudden stop. Model SRV-PH consists of a main valve, solenoid valve, and N2 bottle, completely assembled and tested as a unit and ready for field installation. Main Valve is closed tightly when normal operation is in state. When a exceed pressure in piping system is occurred, surge command from pressure transmitter operates the solenoid valve, and main valve is open for protect the surge (Water hammer). It’s fully opening time is less than 100 millisecond.