The difference and advantages of one-way sealing butterfly valve and two-way sealing butterfly valve

Compared with the one-way sealing butterfly valve, the two-way sealing butterfly valve has better sealing performance, wider application range and longer service life. However, at the same time, because the structure of the two-way sealing butterfly valve is more complex, the cost of manufacturing and maintenance is relatively higher, and when used in the actual fluid pipeline system, it needs to be comprehensively considered and selected according to various factors of working conditions and budget.

The single eccentric hard seal butterfly valve we routinely use is usually a one-way seal butterfly valve, the valve body marked with an arrow indicating the direction of the medium flow, in the valve installation need to pay attention to the medium flow direction. When the butterfly valve is closed, it can only withstand the pressure on one side, and when there is pressure on the other side, leakage will occur. The two-way sealing butterfly valve, whether under forward or reverse pressure, can achieve zero leakage, and there is no need to consider the medium flow direction during installation.

Two-way sealing butterfly valves include traditional wafer resilient sealing butterfly valves, multi-level two-way mental seat butterfly valves and all-metal two-way pressure butterfly valves. The center of the valve body, the center of the butterfly disc and the shaft of the valve stem are in the same center line, using rubber or polytetrafluoroethylene and other materials to seal, good sealing performance, but only suitable for low pressure and normal temperature fluid pipeline system. The multi-layer bi-directional hard seal butterfly valve is an improvement on the basis of the traditional multi-layer mental seat butterfly valve, and the sealing performance of the mental seat butterfly valve can be 1:1 bi-directional pressure in positive and negative directions. The all-metal bidirectional pressure butterfly valve is not only bidirectional pressure, but also has an obvious feature, that is, the sealing ring is completely made of metal materials, without the sandwich of non-metallic materials such as asbestos plate and graphite, which improves the erosion resistance of the sealing ring, thus extending the service life of the butterfly valve. Because the seals are all made of metal materials, the bimetal bidirectional pressure butterfly valve can also be applied to harsh conditions such as high temperature, low temperature and high pressure.

Compared with the one-way sealing butterfly valve, the two-way sealing butterfly valve has better sealing performance, wider application range and longer service life. However, at the same time, because the structure of the two-way sealing butterfly valve is more complex, the cost of manufacturing and maintenance is relatively higher, and when used in the actual fluid pipeline system, it needs to be comprehensively considered and selected according to various factors of working conditions and budget.