Application of triple eccentric butterfly valves

Before the appearance of the three-eccentric butterfly valve, the butterfly valves commonly used in industrial pipelines were wafer butterfly valves, single-eccentric butterfly valves and double-eccentric butterfly valves. Among these butterfly valve products, the wafer butterfly valve has excellent sealing performance and can achieve zero leakage, but the temperature and pressure resistance is poor, and the erosion resistance is poor. The sealing performance of single eccentric butterfly valve and double eccentric butterfly valve cannot be guaranteed. Is there a butterfly valve that can have the advantages of the above several butterfly valves at the same time, the triple eccentric butterfly valve came into being and has been widely used.

Triple eccentric butterfly valve is a hard seal butterfly valve, it is the high temperature, corrosion resistant alloy material surfacing on the seat sealing ring surface layer, the multi-layer soft stacked sealing ring is fixed on the butterfly plate, this production process makes the three eccentric butterfly valve more suitable for high temperature and high pressure environment than the general butterfly valve, corrosion resistance is also stronger. In addition, thanks to the unique design of the triple-eccentric butterfly valve, there is no friction between the butterfly disc and the valve body when the valve is opened and closed. When the valve is closed, the torque increase of the transmission mechanism can provide a compensation seal, which greatly improves the sealing performance of the triple-eccentric butterfly valve and extends the service life of the butterfly valve.

However, although there are many advantages of the triple-eccentric butterfly valve, the application conditions are also very wide, but limited by its own structure, the triple-eccentric butterfly valve also has shortcomings. For example:

1. the butterfly disc of the triple-eccentric butterfly valve because of the special process, the thickness will be relatively large, if used in small-caliber pipelines, the flow resistance will be very large.

2. In the pipeline that needs to be opened frequently, the multi-layer sealing ring on the sealing surface of the triple-eccentric butterfly valve seat and the butterfly plate will be positively washed by the medium in the pipeline, and the long-term wash will affect the sealing of the valve and affect the service life.