What is the hard back seat and soft back seat of the butterfly valve

The hard back seat and soft back seat of the butterfly valve are both talking about the valve seat of the soft seal butterfly valve. Both valve seats can achieve zero leakage, the service life is the same, and for the price, hard back seat will be cheaper.

What is the difference between hard back seat and soft back seat of butterfly valve?

In fact, it is very simple. The hard back seat is difficult to replace when pressed by the machine. The soft back seat can be manually removed and replaced. Let's take a look at the comparison chart:

Appendix：

The valve seat is a removable surface part in the valve, which is used to support the fully closed position of the valve core and forms a sealing pair. Generally, the seat diameter is the maximum flow diameter of the valve. For example, butterfly valve seat materials are very wide, all kinds of rubber, plastic, metal materials can be used as the seat material, such as: EPDM, NBR, NR, PTFE, PEEK, PFA, SS315, STELLITE and so on.

The material properties that should be considered when selecting a soft seal valve seat are
1) Fluid compatibility, including swelling, loss of hardness, permeability, degradation;
2) hardness;
3) permanent deformation;
4) the degree of recovery after load elimination;
5) Lazhong and compressive strength;
6) deformation before rupture;
7) Modulus of elasticity.