In industrial pipeline systems, preventing medium backflow is a crucial link in ensuring the safe and stable operation of the system. As a novel-structured and high-performance check device, the dual-plate check valve, with its unique design and excellent functions, has been widely used in fluid transportation systems in many industries. The structure of the dual-plate check valve mainly consists of a valve body, valve flaps, valve shafts, springs, sealing rings and other components. Different from traditional swing-type or lift-type check valves, it adopts two symmetrically distributed semicircular valve flaps. These two valve flaps are connected by a valve shaft and installed inside the valve body, and the valve flaps can rotate freely around the valve shaft. The spring is usually installed between the two valve flaps or at the connection between the valve flaps and the valve body, providing reset force for the valve flaps to ensure that the valve flaps can close quickly when the medium stops flowing or flows backward. The flow channel of the valve body is designed to be smooth, so the resistance when the medium passes through is small. Moreover, the components in contact with the medium are mostly made of wear-resistant and corrosion-resistant materials such as cast iron, cast steel, and stainless steel to adapt to different media and working conditions.
Its working principle is based on the interaction between the thrust of the medium flow and the spring force. When the medium flows in the specified direction, the thrust of the medium overcomes the elastic force of the spring, pushing the two valve flaps to rotate around the valve shaft and open, forming a smooth flow channel for the medium to pass through smoothly. At this time, the valve flaps are in the open state, and the resistance to the medium flow is small. When the medium flow stops or there is a tendency of backflow, the thrust of the medium disappears or reverses direction, and the elastic force of the spring will quickly push the two valve flaps to rotate in the closing direction, making the valve flaps tightly fit on the valve seat, thereby blocking the backflow of the medium. This quick-closing feature can effectively prevent the occurrence of water hammer, avoiding damage to pipelines, pumps and other equipment caused by medium backflow.
The dual-plate check valve has many significant advantages. Firstly, it has a rapid response. Due to the adoption of the dual-valve flap structure and spring reset design, it can close quickly at the moment of medium backflow, and the closing time is usually shorter than that of traditional check valves, which can timely block the backflow and protect the system safety. Secondly, the fluid resistance is small. Its smooth flow channel design and the position of the valve flaps when opened result in small pressure loss when the medium passes through, which helps to improve the transportation efficiency of the pipeline system and reduce energy consumption. Moreover, it has a compact structure, small volume and light weight. Compared with swing-type check valves of the same specification, its weight can be reduced by more than 30%, and the installation space requirement is small, which is especially suitable for pipeline layout scenarios with limited space. In addition, it is easy to maintain. The disassembly and maintenance of the valve are relatively simple, and vulnerable parts such as valve flaps and springs are easy to replace. Also, due to fewer wearing parts, it has a longer service life, which can reduce maintenance costs and downtime.
In practical applications, dual-plate check valves are widely used in pipeline systems of industries such as petroleum, chemical industry, electric power, water treatment, water supply and drainage, and metallurgy. On the outlet pipeline of the water pump, it can effectively prevent medium backflow when the water pump stops, avoiding damage to the water pump impeller due to reverse rotation; in the material transportation pipeline of chemical production, it can prevent mutual channeling of media between different processes, ensuring the stability of the production process; in the steam and water systems of thermal power plants, it is used to prevent backflow of steam or water, ensuring the safe operation of key equipment such as boilers and steam turbines; in urban water supply and drainage systems, it is installed on the water delivery pipeline to prevent water backflow caused by pressure fluctuations in the pipe network, ensuring the continuity and stability of water supply.
With the development of industrial technology, the performance of dual-plate check valves is constantly optimized. New types of dual-plate check valves adopt more advanced sealing materials, such as polytetrafluoroethylene and nitrile rubber, to improve the sealing performance, ensuring zero leakage even under harsh working conditions such as high pressure and high temperature. At the same time, improvements have been made in structural design, such as the adoption of adjustable springs, which can adjust the spring force according to different working pressures and medium characteristics, so that the valve can maintain the best working state under various working conditions. In addition, some dual-plate check valves are also equipped with buffer devices to further reduce the impact force during closing, reduce noise and vibration, and prolong the service life of the equipment.
To sum up, with its advantages of rapid response, low resistance, compact structure and convenient maintenance, the dual-plate check valve has become an ideal choice for preventing medium backflow in industrial pipeline systems, providing reliable guarantee for the safe and efficient operation of various fluid transportation systems.
