The difference between eccentric butterfly valve and wafer butterfly valve

Butterfly valve is a commonly used industrial valve, there are mainly two types of eccentric butterfly valve and wafer line butterfly valve on the market. This paper will introduce the basic structure and working principle of eccentric butterfly valve and wafer line butterfly valve, and focus on analyzing their differences.

First, eccentric butterfly valve

Eccentric butterfly valve is a valve based on eccentric design, which is characterized by a certain eccentric distance between the valve seat and the butterfly plate, which can make the butterfly plate contact with the valve seat evenly when closed, reducing wear and poor sealing. The structure of eccentric butterfly valve is composed of butterfly plate, valve stem, valve seat, eccentric shaft and shell. When opening the eccentric butterfly valve, the butterfly plate opens or closes the pipe by rotating 90 degrees. Due to the eccentric distance between the seat and the disc, the eccentric butterfly valve is better sealed and suitable for use in high temperature, high pressure or corrosive media.

Second, the middle line butterfly valve

The wafer line butterfly valve is a valve based on the wafer line design, which is characterized by the butterfly plate moving close to the seat. Compared to eccentric butterfly valves, centre-line butterfly valves are simpler and react faster when opened or closed. Because there is no eccentric distance between the butterfly plate and the seat, the wafer line butterfly valve is more susceptible to fluid erosion and corrosion than the eccentric butterfly valve, so it is not suitable for use in high temperature, high pressure or corrosive media.

Three, the difference between eccentric butterfly valve and wafer line butterfly valve

1. Structural differences: The structure of eccentric butterfly valve is relatively complex, including the butterfly plate, valve stem, valve seat, eccentric shaft, shell, etc. The wafer line butterfly valve is much simpler, including only the butterfly plate, valve stem, seat and housing.

2. Difference in working principle: eccentric butterfly valve because there is a certain eccentric distance between the butterfly plate and the valve seat, so the butterfly plate can contact the valve seat evenly when closed, and can be used in high temperature, high pressure or corrosive media, while the middle line butterfly valve is easy to leak when used in high temperature, high pressure or corrosion-prone media because the butterfly plate is close to the valve seat.