Can wafer butterfly valves be connected using flat welding flanges? Is it necessary to use a flange specific for butterfly valves? Are there any standard specifications?

Wafer butterfly valves are generally not recommended to be connected using flat welding flanges, as they are designed to be clamped directly between two flanges; using specialized butterfly valve flanges helps to ensure better sealing at the interface as well as greater strength in the connection. For diameters of DN300 and above, flanges specifically designed for butterfly valves should be used to withstand greater pressures and hydrodynamic forces. Regarding installation standards, international standards such as ISO 5752, ISO 10631, and European standards such as EN 558 can be referred to; these standards provide specific guidelines on the installation of butterfly valves and the types of flanges to be used. At the same time, it is also necessary to refer to the installation guidelines and recommendations provided by the butterfly valve manufacturer. .

Conventional flat welding flanges can be used; simply specify the technical requirements when placing the order. In butt butterfly valves, the middle valve plate may experience interference with the edges and corners when it is opened or closed; this problem is common with plastic flanges. Valve manufacturers take precautions to avoid such issues when designing carbon steel flanges. Furthermore, the flanges of butterfly valves are generally rated at 6–10 kgf; by using PL16 flanges, these problems can basically be avoided