Selection of common butterfly valves

Butterfly valve is one of the most commonly used valve types in industrial valves, especially suitable for low pressure and large diameter applications. The butterfly plate of the butterfly valve is installed in the diameter direction of the pipe. In the cylindrical channel of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0 ° and 90 °. When it rotates to 90 °, the valve is fully open.
The butterfly valve is simple in structure, small in size and light in weight, and consists of only a few parts. Moreover, it can be opened and closed quickly by only rotating 90 °, and the operation is simple. At the same time, the valve has good fluid control characteristics. When in the fully open position, the thickness of the disc is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is small, so it has good flow control characteristics. The butterfly valve has two types of sealing: spring seal and metal seal. Elastically sealed valve, the seal ring can be embedded in the valve body or attached to the periphery of the butterfly plate.
      Metal sealed valves generally have a longer life than elastically sealed valves, but it is difficult to achieve a complete seal. Metal seals can adapt to higher operating temperatures, while elastic seals have the disadvantage of being temperature limited. If butterfly valves are required for flow control, the main thing is to choose the correct valve size and type. The structural principle of the butterfly valve is especially suitable for making large-caliber valves. Butterfly valves are widely used not only in general industries such as petroleum, gas, chemical, and water treatment, but also in cooling water systems for thermal power stations.
      There are two types of wafer type butterfly valve and flange type butterfly valve. Wafer type butterfly valve uses double-headed bolts to connect the valve between two pipe flanges. Flange type butterfly valves have flanges on the valve, and bolts are used to connect the two ends of the valve to the pipe flange. The strength performance of the valve refers to the ability of the valve to withstand the pressure of the medium. The valve is a mechanical product that can withstand internal pressure, so it must have sufficient strength and rigidity to ensure long-term use without rupture or deformation.