Types of butterfly valves can be categorized according to several criteria, mainly including:
Connection form:
- Wafer Type Butterfly Valve: the butterfly plate is installed in the direction of the pipe diameter, simple structure, small size, light weight.
- Flanged butterfly valve: vertical plate structure, the valve stem is an integral metal hard seal, the seal is a flexible graphite plate and stainless steel plate composite structure.
- Welded butterfly valve: non-closed type butterfly valve, suitable for building materials, metallurgy, mining, electric power and other production processes, medium temperature ≤ 300 ℃, nominal pressure of 0.1MPa.
- Butterfly valve: the valve body with internal or external threads, and pipeline threaded connection.
- Clamp Butterfly Valve: with speed reducer on the valve stem, so that the butterfly plate stops at any position to improve the operating performance of the valve.
Driving mode:
- Electric Butterfly Valve: Electricity as driving force, consisting of electric actuator and butterfly valve, suitable for large diameter pipeline, can also be used for water, air, oil, etc. control and regulation.
- Manual butterfly valve: including handle butterfly valve and turbo butterfly valve, simple structure, small size, light weight, suitable for rapid opening and closing.
- Pneumatic Butterfly Valve: with compressed air as driving force, small size, light weight, suitable for small diameter pipeline, also can be used for gas, air, water and other control.
- Pneumatic butterfly valve: mainly used in high safety level system, such as steam turbine pumping pipeline, blast furnace gas residual pressure power generation device, etc. It is suitable for seawater, sewage, flue gas and other industrial pipeline network for emergency shut-off valve.
Sealing surface material:
- Soft seal butterfly valve: the sealing surface is composed of non-metallic soft material to non-metallic soft material, commonly used materials are common nitrile rubber, fluorine rubber and so on.
- Hard seal butterfly valve: sealing vice by metal hard material to metal hard material composition, commonly used materials are STL alloy surfacing.
Structure form:
- Concentric butterfly valve: stem axis, butterfly plate center, body center in the same position, simple structure, easy to manufacture, but the resistance distance is large, fast wear.
- Single eccentric butterfly valve: the stem axis deviates from the center of the butterfly plate, so that the upper and lower ends of the butterfly plate no longer become the axis of rotation, dispersed to alleviate the excessive extrusion of the upper and lower ends of the butterfly plate and the valve seat.
- Double Eccentric Butterfly Valve: On the basis of single eccentric butterfly valve, it is further improved and molded so that the butterfly plate can be quickly detached from the valve seat after the valve is opened, which greatly eliminates the unnecessary over-extrusion between the butterfly plate and the valve seat.
- Triple Eccentric Butterfly Valve: further improved on the basis of Double Eccentric Butterfly Valve, the shape of the sealing vice is not a positive cone but a slant cone, which improves the sealing performance.
