Safety is very important in our life. In some factories […]
Safety is very important in our life. In some factories or machinery, safety valves are used. This equipment allows us to have a certain guarantee on the safety of use or production. How to use safety valves well, first of all we need to know How the safety valve works. So do you know how the safety valve works?
The safety valve is a special valve that the opening and closing parts are in a normally closed state under the action of external force. When the pressure of the medium in the equipment or pipeline rises beyond the specified value, it discharges the medium to the outside of the system to prevent the medium pressure in the pipeline or equipment from exceeding the specified value. . Safety valves are automatic valves, mainly used in boilers, pressure vessels and pipelines. The control pressure does not exceed the specified value, which plays an important role in protecting personal safety and equipment operation. NOTE The safety valve must be pressure tested before it can be used.
When the steam pressure under the disc of the safety valve exceeds the pressing force of the spring, the disc is pushed open. After the valve disc is pushed open, the discharged steam acts on the valve disc holding ring due to the rebound of the lower adjusting ring, so that the valve opens quickly. With the upward movement of the valve disc, the steam impinges on the upper adjusting ring, so that the direction of the exhaust steam tends to be vertically downward, and the reaction force generated by the exhaust steam pushes the valve disc upward and keeps the valve disc at a certain pressure within a certain pressure range. With sufficient lifting height, with the opening of the safety valve, the steam is continuously discharged, and the steam pressure in the system is gradually reduced. At this time, the force of the spring will overcome the steam pressure acting on the valve disc and the reaction force of the exhaust stream, thereby closing the safety valve.
The working principle of the spring-loaded safety valve is pressure = pressure X area. The pressure is the pressure of the spring, and the area is the area of the sealing surface. When the upward thrust formed by the pressure acting on the sealing surface multiplied by the area of the sealing surface is greater than the pressure of the spring, the spring is compressed, the sealing surface is opened, and the pressure is discharged through the pressure relief hole.