Concentric butterfly valves

Structural characteristics of concentric butterfly valves are that stem axis, the center of the disc and the central body are in the same position. The concentric center line butterfly valves have a simple structure, can be easy manufactured. The rubber lined concentric butterfly valve that is the most common type in this category.

The disadvantage of the concentric butterfly valve is that due to the disc and seat is always in the squeeze, their scratch stated and resistance lead to fast wear. A concentric rubber lined butterfly valve relies on an interference fit between the valve disc and liner. 

Because the old types of sealing materials are restricted to be used at higher temperatures, traditionally people think concentric butterfly valves can’t be used in high temperatures.

However the concentric butterfly valves to ensure good sealing performance, the seat is basically made of high temperature material such as rubber or Teflon.