Application Range of Pneumatic and Hydraulic Safety Valves
Safety valves are important devices in the safety protection of pressure vessels and pressure pipes. With the development of science and technology and the innovation of design concept, the current types of safety valves are more and more abundant. According to the drive, they can be divided into hand, cylinder, air-hydraulic, pilot, etc. According to the structure, they can be divided into single-seat balance and two-seat balance. According to the driving force and pressure, there are spring-loaded, gravity-loaded and direct-loaded safety valves. According to the opening and closing parts, there are lift safety valves, and flat safety valves. They are widely used in nuclear power plants, chemical industry, and oil and gas industry.
The air-hydraulic safety valve is a kind of pressure relief valve that is pressed by a combination of air pressure and hydraulic pressure. Its operating principle is mainly the balance of air pressure and hydraulic pressure. When the pressure of the protected system exceeds the set valve, the valve is opened by the force of the hydraulic piston and the compressed air, so as to release the pressure of the protected system. When the set pressure is lower than the pressure of the protected system, the valve is closed under the action of the system pressure and the spring force.
The application range of air-hydraulic safety valve mainly includes: high and low pressure steam systems, super heaters and other high temperature systems, supercritical state systems, all kinds of air pressure systems, etc. The air-hydraulic safety valve must be installed horizontally on the pipeline in the direction of media flow. The connection size should meet the medium working pressure, temperature and nominal diameter of the pressure relief valve.
The working principle and application of the air-hydraulic safety valve are similar to that of the ordinary safety valve. Its main difference is that it combines the properties of the gas and the liquid in one device. Its mechanical structure is simple and reliable, suitable for use in occasions that ordinary safety valves cannot meet due to high back pressure and earth vibration, enabling the valve to be more intelligent and precise when servicing. In addition, when the valve is opened, the pressure relief capacity of the valve can reach the maximum, and the noise level is also within the allowable range, which cannot be achieved by ordinary safety valves.
In short, the application range of air-hydraulic safety valves is very wide, and it is widely used in various high-pressure systems and large-scale technological transformation projects. It is an economic and convenient pressure protection equipment, which is favored by users. At the same time, the design of air-hydraulic safety valves can be changed according to different requirements and pressure protection points, so as to play an even better role in pressure protection.
