Butterfly valve is a fluid switch that uses a disc-type opening and closing part to reciprocate about 90 degrees. It usually functions as a blocking opening, flow regulating valve and damping valve in liquid, gas, and other fluid pipeline systems. Butterfly valves can be divided into two most common types according to the connection method: wafer butterfly valve and double flange butterfly valve.
There is no flange on the valve body of the wafer butterfly valve. Use stud bolts to connect the valve between the two pipe flanges. The butterfly valve is sandwiched between two flanges, and then the two flanges are fixed with bolts. live. The valve body of the double-flange butterfly valve has a flange, and the flanges at both ends of the valve are connected to the pipe flanges with bolts.Due to this structural difference, the installation positions of wafer butterfly valves and double flange butterfly valves are different.
In addition to the difference in connection methods, there is another basic difference in butterfly valves, that is, size, that is, caliber. Large size butterfly valves have larger diameters and can carry greater fluid pressure.Large diameter butterfly valve refers to a valve with a diameter greater than 100cm.
Large size double flange butterfly valves and large size wafer butterfly valves are commonly used and are important parts in industry.
Connection methods of butterfly valves are installed differently
- The wafer butterfly valve’s boltsare relatively long, and there is no flange itself, so it is generally not installed at the end of the pipeline or in the downstream position that needs to be disassembled, because when the downstream flange is disassembled, the wafer butterfly valve will fall, so that the two sides of the valve The pipes at both ends can no longer work normally;
- The double flange butterfly valve does not have such a problem. The valvebody has a flange. When paired with the flange on the pipe, it is connected with bolts and locked with nuts, so when one end is removed, It will not affect the operation of the other end.
Price and selection of connection methods
- Double flangebutterfly valves have longer bolt lengths. The requirements for construction accuracy are high. If the flanges on both sides are misaligned, the bolts will be subject to relatively large shear forces, causing the valve to leak easily, so the cost is higher.
- In comparison, the wafer butterfly valve is more convenient to disassemble and the cost is lower, but the disadvantage is that if there is a problem with one sealing surface, both sealing surfaces must be disassembled.
When choosing butterfly valves, TWT,China do not recommend that buyers buy expensive or cheap ones, but hope that customers understand their needs and then make targeted choices.
In general, wafer butterfly valves are light in weight, simple in structure, and easy to operate. Although they do not maintain zero leakage like flange butterfly valves, they can meet ordinary work needs. Double flange butterfly valves have a long service life, are not easy to wear, have low leakage, and are also more expensive.
TWT,China can provide first-class quality for both types of butterfly valves, and customers are welcome to inquire or place orders.
Application of butterfly valves of different types and sizes
Wafer-type valves are more commonly used in the chemical industry, especially in the sulfur acid production industry. They are the preferred valves and are used in all aspects of the sulfur acid production system process, including the flow of gas pipelines in sulfur incineration and dry suction. Control to ensure the smooth progress of the entire acid-making process. In addition, wafer-type butterfly valves are often used at the entrances of relay fans, blowers, preheaters and other devices. They are used as valves to adjust and cut off the gas volume, and can also be used to adjust converters.
Double flange butterfly valves are widely used in production pipelines in general industries such as water conservancy projects, water treatment, petroleum, chemical industry, urban heating, etc. They can also be used in condensers and cooling water systems of thermal power stations. Double flange butterfly valves are particularly suitable for large-diameter valves.
Large size double flange butterfly valve are widely used in the field of large-diameter regulation. When the French double-flange butterfly valve is fully opened, the flow resistance is small. When the opening angle of the butterfly plate is between about 15-70 degrees, The double flange butterfly valve can control the medium flow rate very sensitively. Large size double flange butterfly valve is commonly used in low-pressure large and medium-diameter pipelines.
Features of large size double flange butterfly valve
Large size double flange butterfly valve have these advantages below:
- Light weight and beautiful appearance.
- Functionally, it can replace many products with incomplete functions, simplify the shape, and solve the shortcomings of complex factory management, complex selection, and heavy maintenance workload.
- Large-diameter butterfly valves have a large adjustability ratio, generally up to 100, and can ensure good adjustability from 10% to 90% of the opening.
- Smooth action and extremely high reliability, which can solve the fatal structural defects of traditional valves with large leakage.