Metal sealed butterfly valve has the features are not available in ordinary valves.Especially small flow resistance, reliable sealing, opening and closing fast, long service life etc.. Ring sealing force from the elastic deformation of three eccentric metal sealing butterfly valve developed in our country to achieve sealing, which does not require interaction with media, it can do two-way seals. According to some characteristics of butterfly valves will be more and more people are paying attention to. In the future there will be more applied to the low-temperature device valve.

With the rapid development of industrial technology, puts forward more strict requirements for the valve industry, especially for low-temperature medium used in the butterfly, in addition to meet the general performance of the valve is outside,more important is in the low temperature valve seal reliability, flexibility of movement as well as low temperature valve on a number of other special requirements.

With the rapid development of industrial technology, puts forward more strict requirements for the valve industry, especially for low-temperature medium used in the butterfly, in addition to meet the general performance of the valve is outside,more important is in the low temperature valve seal reliability, flexibility of movement as well as low temperature valve on a number of other special requirements.

As everyone knows, the valve has a compact structure, small size, light weight (with the same pressure, the valve diameter compared to the same reduce 40% ~ 50%)fluid resistance small, open and close rapidly and a series of advantages. But someof China's low-temperature devices such as natural liquefaction equipment, air separation equipment, and pressure swing adsorption equipment such as valves used in the chemical industry more than 80% cut-off valve or gate valve, butterfly valve using a small number. Analysis of the main reasons is too metal sealing butterfly valve in the low temperature sealing performance under adverse conditions, and other irrational structure caused by medium leakage and leakage,serious implications of these low-temperature equipment safety and normal operation, can not meet the requirements of low temperature equipment.

According to the continuous development of low temperature devices, the requirements for increasing low temperature valve, to meet the needs of the market economy, the metal sealing butterfly valve for structural improvements, developeda butterfly valve with three eccentric high sealing performance of pure metalwhether the medium is high or low temperature can meet their needs.

Low temperature valve leakage are two main causes of the situation, one leakage;two is the leakage.

1) mainly due to leakage within the valve sealing at low temperature due to deformation. When the medium temperature dropped to the material phase change caused by volume changes, so that the original sealing surface with high precision grinding produces warpage caused by low-temperature sealing side. We have low temperature test of DN250 valve, medium is liquid nitrogen (-196 ℃) butterfly platematerials for 1Cr18Ni9Ti (not after low temperature treatment) found that thesealing surface of the warping deformation of about 0.12mm, which is the main reason causing the inner leakage.

The newly developed valve cone from the flat seal to seal. Is an oblique elliptical cone seat sealing surface, and is of circular elastic embedded in the disc sealingring sealing. Seal ring groove in the disc radial float. When the valve is closed, the first elastic sealing ring and sealing surface of the short axis of contact ellipse.