Concept and working principle of the hottest emerg

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Concept and working principle of emergency shut-off valve

I. what is an emergency shut-off valve

emergency shut-off valve is one of hydraulic control valves. It is composed of main valve, throttle valve, pilot valve, pressure gauge, nozzle and other pipe fittings. It is a new product developed in recent 3 years with high reliability, and its application in engineering is increasing. A good product is not only good in quality, but also the most important thing is to let everyone know it, get familiar with it and use it reasonably, so that it can play its greatest role

II. Reasons for using the emergency shut-off valve:

1. As we all know, the fire pipe and living pipe have always been two water supply systems, which are supplied by two pump groups respectively, and the water is supplied by two-way pipes for a long distance from the pump room to the building. In this way, due to the large construction workload of laying two-way pipelines, double the pipeline materials, and there are many inconveniences in identifying a certain pipeline during maintenance

2. The fire-fighting pipeline is not used for many years, which is easy to rust. The pipe wall and interface are thinned due to corrosion, so there is no pressure at ordinary times. Once a fire alarm occurs, the pressure in the pipeline suddenly increases, which is easy to burst, causing the fire-fighting system to fail to supply water

3. Shanghai advocates that water pumps directly draw water from municipal pipes and no longer set up underground pools. This saves the cost of building the pool. If there is an oil leak, add a cushion at the interface and tighten it. At the same time, great efforts are made to avoid the secondary pollution of the water source. The most important thing is to keep the water clean and ensure the health of the people. Because of these advantages, this product is gradually being welcomed by everyone

II. Working principle of emergency shutdown valve

emergency shutdown valve is composed of main valve, throttle valve, pilot valve, pressure gauge, connecting pipe and other pipe fittings. When the inlet pressure of the main valve is lower than the pressure set by the pilot valve whose hardness must be low, the pilot valve is now in the open state, the pressure in the upper cover cavity of the main valve is equal to the outlet pressure of the main valve, there is a pressure difference between the inlet and outlet, and the water flows out of the outlet through the valve port. When the fire pump starts, or the pressure of the variable-frequency pump rises, which exceeds the set pressure of the pilot valve, the pressure from the main valve inlet to the pilot valve control pipe rises, the pressure acting on the spring increases, presses down, drives the valve core to move down, and closes the pilot valve. At this time, the main valve inlet pressure is continuously supplemented to the upper chamber of the main valve cover through the throttle valve. Because the downward pressure on the valve disc is greater than the upward thrust, the main valve closes. Please note that the key point is that the valve is always open when the inlet pressure is less than the set pressure, and closed when the inlet pressure is greater than the set pressure. Now many designers mistakenly think that as long as the emergency shut-off valve is installed, it will close, without any conditions, that is wrong

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