With the rapid development of industrial technology, more stringent requirements have been put forward for the valve industry, especially for butterfly valves used in low temperature media. In addition to meeting the performance of general valves, the more important thing is that the valve seals under low temperature conditions. The reliability, flexibility of action and some other special requirements for cryogenic valves, so Ultra-low temperature flange triple eccentric butterfly valve is launched. The product has been designed with three eccentric torque shutoffs, and a certain force is applied to the metal elastomer valve seat, so that the blade and the valve seat can achieve a tight fit. It can prevent leakage due to the influence of thermal expansion and contraction due to temperature.

Ultra-low temperature flange triple eccentric butterfly valve has a series of advantages such as compact structure, small size, light weight (compared with gate valves with the same pressure and diameter can be reduced by 40% to 50%), small fluid resistance, and rapid opening and closing. However, more than 80% of the valves used in some low-temperature devices in my country, such as natural gas liquefaction equipment, air separation equipment, and pressure swing adsorption equipment, are cut-off valves or gate valves, and the number of butterfly valves is very small. Analysis of the reasons is mainly due to the poor sealing performance of metal-sealed butterfly valves at low temperatures, and other reasons such as unreasonable structures that cause internal and external leakage of the medium, which seriously affects the safety and normal operation of these low-temperature equipment, and cannot meet the low-temperature requirements. equipment requirements.

There are two main reasons for the leakage of Ultra-low temperature flange triple eccentric butterfly valve, one is internal leakage; the other is external leakage. The main reason for the internal leakage of the valve is the deformation of the sealing pair at low temperature.