Pressure relief valve, also known as safety valve, can automatically open and close according to the working pressure of the system. It is generally installed on equipment or pipelines in closed systems to protect system safety. When the pressure inside the equipment or pipeline exceeds the set pressure of the pressure relief valve, the pressure relief valve will automatically open to ensure that the medium pressure inside the equipment and pipeline is below the set pressure, protecting the equipment and pipeline and preventing accidents.

 

A pressure relief valve is a type of hydraulic control valve composed of needle valves, pressure gauges, main valves, pilot valves, and connecting pipes. The main valve is divided into upper and lower parts by a diaphragm. The lower chamber of the diaphragm is the water flow channel, and the upper chamber is the control chamber, which controls the opening and closing of the main valve disc. The pilot valve itself is a pressure relief valve, which also has a control room and a water flow channel. The opening and closing of the valve disc is controlled by the control room. Needle valve, also known as throttle valve, controls the flow of water in the connecting pipe.

 

During the operation of the fire water supply system, the hydraulic control valve controls the water flow direction from left to right in the main pipeline, and controls the water to enter the pilot valve control room. When the water pressure is less than the set relief value, the thrust of the pilot valve spring is greater than the water pressure, and the pilot valve disc is in the closed state. The other way controls the water to enter the upper chamber of the main valve through a throttle needle valve, generating a static pressure. The pressure in the upper chamber is equal to the pressure in the raw flow channel. Due to the fact that the upper plane of the main valve disc is greater than the lower plane, the pressure of the upper chamber on the disc is greater than the push of the water on the main channel, causing the main valve to be in a closed state. If the water flow pressure in the main pipeline rises and exceeds the set pressure relief value, the water flow pressure entering the control room through the control pipe increases, and the water pressure is greater than the spring thrust. At this time, the pilot valve is opened and the main valve begins to release pressure. Due to the control of the throttle valve, insufficient water replenishment caused a decrease in pressure in the upper chamber of the main valve, resulting in bone marrow ice under the same valve The flow thrust increases the pressure in the upper chamber, causing the valve disc to rise and the main valve to quickly release pressure. Due to the instantaneous completion of the above process, the indoor fire water supply system will not cause harm in the event of overpressure.