In the selection process of the valve fitting butterfly valve, in addition to its structural form and service life, the sealing requirements for it must also be considered. When using the soft seal method, most of the butterfly valves used in the water supply network are soft-sealed butterfly valves. This type of sealing may occur in the following situations:
First of all, the soft seal parts in the valve fitting butterfly valve are prone to aging, long-term compression deformation and extrusion cracking due to poor material quality. Secondly, the butterfly ring is damaged during the installation and construction process, which affects the sealing property; The soft sealing butterfly valve is difficult to ensure the concentricity of the butterfly plate in the valve body cavity, and the sealing problem is often solved by excessive extrusion, so the service life of the valve is short.
When the metal seal is used, considering that the metal sealing butterfly valve of the valve fitting is not easy to be damaged due to the small elasticity of the sealing member, the sealing surface of the metal sealing butterfly valve is not easily damaged, but its manufacturing precision is high, and once the leakage is difficult to repair, the price is relatively high. high. Therefore, the main factors we should consider when selecting the model are: butterfly valve sealing surface rubber ring material, fixing method; important parts size, precision, material; butterfly valve operating environment; price factor.http://www.dmgcastings.com/