Principle of High Pressure Shut-off Valve
The pilot valve is opened when the inlet pressure of the main valve is lower than the set pressure of the pilot valve. The main valve opens and water flows out through the main valve through the outlet. When the firefighting pump starts or frequency conversion pump pressure increases, exceeding the set pressure of the pilot valve, the pressure of the main valve inlet guide valve is increased, the pressure acting on the spring is increased, the pressure is pressed down, the pilot valve is closed. At this point, the inlet pressure of the main valve is continuously supplemented to the control room of the main valve through the ball valve. The downward pressure on the valve disc is greater than the upward thrust to close the main valve.