How the butterfly valve works

A Butterfly Valve is a type of valve that uses a round butterfly plate as an opening and closing element and opens, closes, and adjusts a fluid passage as the valve stem rotates. The butterfly plate of the butterfly valve is installed in the diameter direction of the pipe. In the cylindrical passage of the butterfly valve body, the disc-shaped disc rotates around the axis, and the rotation angle is between 0° and 90°. When the rotation is 90°, the valve is fully opened.

The structural characteristics of the butterfly valve has a simple structure, small size, light weight, material consumption, small installation size, rapid switching, 90 reciprocating rotation, small drive torque characteristics, used to cut off, connect, adjust the pipeline Medium, with good fluid control properties and closed sealing properties. When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is very small, so it has better flow control characteristics. The butterfly valve has two types of seals: elastic seal and metal seal. Elastic sealing valve, sealing ring can be mounted on the valve body or attached around the butterfly plate.

Valves that use metal seals generally have longer life than elastomer-sealed valves, but they are difficult to completely seal. Metal seals can accommodate higher operating temperatures, while elastomeric seals have temperature-restricted defects.
If the butterfly valve is required to be used as a flow control, it is mainly the correct choice of the size and type of the valve. The structural principle of the butterfly valve is particularly suitable for making large-diameter 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 of thermal power plants.
The commonly used butterfly valves include three kinds of wafer type butterfly valves, flange type butterfly valves and butt welding type butterfly valves. The clip-on butterfly valve uses a stud bolt to connect the valve between the two pipe flanges; the flanged butterfly valve has a flange on the valve; the upper flanges of the valve are connected to the pipe flange by bolts; butt welding Both ends of the butterfly valve are welded to the pipe.

The streamlined design of the butterfly plate, so that the fluid resistance loss is small, can be described as an energy-saving products.
The valve stem is a through-rod structure. After quenching and tempering, it has good comprehensive mechanical properties, corrosion resistance, and scratch resistance. When the butterfly valve is opened and closed, the valve stem only performs rotary motion without lifting operation. The packing of the valve stem is not easy to damage, and the seal is reliable. The utility model is fixed with a butterfly taper pin, and the outstretched end is of an anti-bump type design, so as to prevent the valve stem from collapsing when the stem and the butterfly plate are accidentally broken.