The allowable tolerance of the set pressure: ≤±3% of the set pressure
Overpressure: ≤±10% of the set pressure
Blow down: ≤±10% of the set pressure
Tightness: The valves have good seat tightness, conforms to API Std 527
Pressure Rating: Inlet Class 150~2500, Outlet Class 150 - 300
Base Material: ASTM A216 WCB, ASTM A351-CF8, Special Steel
Principles of operation
In the normal closed position, system pressure is transmitted through the pilot valve and into the dome of main valve. The pressure above the main valve disc generates a net downward force, hold the main valve closed.
When system pressure reaches the set pressure, the pilot spindle lifts and reseat piston closed simultaneously, venting the dome pressure through the pilot valve to atmosphere. Because of system pressure remains above reseat pressure, the reseat piston is held tightly closed, blocking flow to the pilot valve (the non-flowing pilot valve feature), at this time the dome pressure of main valve is depressed quickly, allowing the main valve to open fully.
When the desired system pressure is achieved, the pilot spring force overcomes force on the reseat piston, the reseat piston snaps open and the pilot spindle snaps closed simultaneously. Finally, system fliud reenter the dome and closes the main valve.
Proper valve operation and lift are unaffected by back pressure.
Non-flowing pilot reduces product loss and environmental pollution.
Quick simple verification of set pressure while valve remains in service.
The system can be operated nearer set pressure without valve leakage.