About emergency shut-off valve

900X emergency shut-off valve is composed of main valve, Needle Valve, pilot valve, pressure gauge and other pipe fittings such as pipe fittings. It is used to adjust the direction of water supply in the water supply system where fire water and domestic corner water are connected in parallel. When a fire breaks out and a large amount of water is urgently needed for firefighting, the 90OX emergency shut-off valve immediately cuts off domestic water to ensure sufficient firefighting water; when the fire-fighting water pressure decreases, the valve automatically opens to a normally open state to restore domestic water supply. Its working principle is that when the main valve inlet pressure is lower than the pressure set by the pilot valve, the pilot valve is in the open state at this time. The pressure in the main valve upper cover cavity is equal to the main valve outlet pressure. There is a pressure difference between the inlet and outlet, and the water flow It flows out from the outlet through the valve port. When the fire pump starts, or the pressure of the variable frequency pump rises and exceeds the set pressure of the pilot valve, the downward pressure is exerted from the main valve connection port through the pilot valve control pipe to the lower chamber of the half-valve valve. Due to the positive thrust, the main valve is closed. It is worth noting that the valve is always open when the inlet pressure is set by Wan Yiyu. If the inlet pressure is greater than the set pressure, the valve is closed. This valve eliminates the need for a separate fire-fighting water supply network in the system, greatly saving construction costs and water consumption.