The safety valve is the largest product in the valve category. It can not only open and close the valve, but also protect the valve. Safety valves play a very important role in some pressure equipment and are indispensable safety accessories. They should be checked frequently to ensure safety and reliability during use. The safety valve is an automatic valve that can adjust itself when the equipment pressure changes.
1. Working principle of safety valve:
The safety valve is so popular not only because it can open and close the valve, but it can also play a protective role. When the equipment is working and the pressure rises above a predetermined value, the safety valve will automatically open the pressure relief function to prevent the equipment pressure from rising continuously; on the contrary, if the equipment pressure is reduced, the safety valve will close by itself to prevent There is a large loss of media in the equipment. So what kind of adjustment does the safety valve need to make before working?
① The safety valve should be adjusted and tested before production, and its pressure value should be adjusted. If users have specific requirements for working pressure, they must be adjusted according to the lower limit of the general pressure level before leaving the factory.
② Before installing the safety valve, the installation site should be adjusted to ensure that the set pressure value of the safety valve can meet the required value limit.
③ Within the standard range of the spring working pressure level indicated on the nameplate, the opening pressure can be adjusted by rotating the adjustment screw to change the spring compression.
④ Before rotating the screw, adjust the screw to reduce the inlet pressure of the valve to less than 90% of the opening pressure. This can prevent the valve from being driven by the rotating screw and damaging the sealing surface.
⑤In order to ensure the accuracy when adjusting the pressure, the medium can be changed, such as the temperature of the medium, the type of the medium, the condition of the medium, etc., so as to make the medium closer to the required pressure condition value as much as possible.
⑥ Under normal circumstances, when the safety valve is used in the occasion of fixed additional back pressure, adjust the setting value of the opening pressure because the opening pressure value is required to subtract the additional back pressure value.
2. The role of the safety valve:
During operation, when the pressure or temperature value of the equipment pipeline exceeds the setting value set by the valve, the safety valve can adjust itself to ensure that the pressure value and temperature in the equipment pipeline are under the set pressure and protect the equipment pipeline Normal work and operation to prevent accidents and reduce damage. The installation diameter of the safety valve is not large, and it is generally installed between dn15mm~dn80mm.
Safety valves are widely used in modern industrial systems, such as high-pressure bypass of steam power generation equipment, liquefied petroleum gas tank cars, pressure pipelines, steam boilers, liquefied petroleum gas railway tank cars, oil production wells, pressure vessels, etc.
3. Overall dimensions of safety valve:
In our country, the valve industry is developing rapidly. The so-called special valve equipment for safety valves is constantly increasing and expanding. Due to the particularity of the safety valve and the huge market demand, it is relatively stricter in the process of national application to ensure the quality assurance of the products at the factory. With the use of different places and purposes, the types of safety valves will also expand. Safety valves can be divided into lever-type safety valves, spring-type safety valves, and pulse-type safety valves according to their structure. Among them, spring-type safety valves are the most widely used; they can also be distinguished according to the connection method, namely flange safety valves and Threaded safety valve.