The Difference Between Flange Butterfly Valve and Wafer Butterfly Valve

Ⅰ. What is the difference between a flange butterfly valve and a wafer butterfly valve?

1. Wafer butterfly valve

The butterfly plate of the wafer butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the butterfly valve body, the disc-shaped butterfly plate rotates around the axial direction, and the rotation angle is between 0°-90°, and the rotation reaches 90° , the valve is fully open.

The wafer type valve is simple in structure, small in size and light in weight. It is composed of only a few parts, and the wafer butterfly valve can be quickly opened and closed by only rotating 90°, and the operation is simple. At the same time, the valve has good fluid control characteristics.

When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the resistance when the medium flows through the valve body, so the pressure drop generated by the valve is very small, and it has good flow control characteristics.

There are two types of sealing, elastic sealing and metal sealing. For elastic sealing valves, the sealing ring can be embedded on the valve body or attached to the periphery of the butterfly plate.

2. Flanged butterfly valve

The butterfly valve flange type is a vertical plate structure, and the valve stem is an integral metal hard seal. The sealing ring of the valve is a composite structure of flexible graphite plate and stainless steel plate, installed on the valve body, and the sealing surface of the butterfly plate is surfacing with stainless steel.

The sealing ring of the soft-sealed valve is made of nitrile rubber, which is a flange-type soft-sealed butterfly valve installed on the butterfly plate.

3. butterfly valve lug type

4. Welded butterfly valve

Welded butterfly valve is a non-sealed butterfly valve, which is widely used in pipelines with medium temperature ≤ 300°C and nominal pressure of 0.1Mpa in the production process of building materials, metallurgy, mining, electric power, etc., to connect, open and close or adjust the medium volume.

Ⅱhe characteristics of the flange butterfly valve

1. Small and light, easy to disassemble and maintain, and can be installed at any position.

2. The structure is simple and compact, the operating torque is small, and the 90°rotation opens quickly.

3. The flow characteristics tend to be straight, and the flange butterfly valve has good adjustment performance.

4. The connection between the butterfly plate and the valve stem adopts a pinless structure, which overcomes possible internal leakage points.

5. The outer circle of the butterfly plate adopts a spherical shape, which improves the sealing performance and prolongs the service life of the valve. It still maintains zero leakage for more than 50,000 times of opening and closing under pressure.

6. The seal can be replaced, and the seal is reliable to achieve two-way seal.

7. The butterfly plate can be sprayed with a coating according to user requirements, such as nylon or PTFE.

8. Flange butterfly valve can be designed as flange connection and wafer connection.

9. The driving mode can be manual, electric or pneumatic.

Flange butterfly valves are suitable for water supply and drainage, sewage, food, heating, gas, shipbuilding, hydropower, metallurgy, energy systems, and textile industries with a temperature of ≤120°C or ≤150°C and a nominal pressure of ≤1.6MPa.

The flanged butterfly valve is especially suitable for two-way sealing and the occasion where the valve body is prone to corrosion. The flanged butterfly valve is used to adjust the flow rate and intercept the medium.