Views: 8235 Author: Site Editor Publish Time: 2020-03-03 Origin: Site
The valve is the control part of the fluid conveying system. It is a mechanical product that controls the fluid flow, pressure and flow direction by changing its flow area, mainly including ball valve, ball valves for steam, check valves, forged steel valves, stop valves. The following mainly introduces a type of valve — flange butterfly valve.
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. 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 opened.
When the flanged 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 small, and it has good flow control characteristics. The butterfly valve has two types of sealing: spring seal and metal seal. The seal ring of elastically sealed valve can be embedded in the valve body or attached to the periphery of the butterfly plate.
The rotation center of the butterfly plate is located on the center line of the valve body and on the sealing surface section of the butterfly plate. The valve seat is made of synthetic rubber. When closed, the outer sealing surface of the butterfly plate squeezes the synthetic rubber valve seat, causing the valve seat to elastically deform, thereby forming an elastic force as the sealing specific pressure to ensure the seal of the butterfly valve. The flange butterfly valve seal structure uses polytetrafluoroethylene and synthetic rubber to form a composite valve seat. Its characteristics are that the elasticity of the valve is still provided by synthetic rubber and uses the characteristics of polytetrafluoroethylene such as low friction coefficient, not easy to wear, not easy to age, so that the service life of butterfly valve can be improved.
1. Small and light, easy to disassemble and repair, and can be installed at any position.
2. The structure is simple and compact, the operating torque is small, and the 90° rotary opening is fast.
3. The flow characteristics tend to be straight and the regulation performance is good.
4. The connection between the butterfly plate and the valve rod adopts a pin free structure, which overcomes the 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 when it is opened and closed under pressure for more than 50,000 times.
6. The seal can be replaced, and the sealing is reliable to achieve two-way sealing.
7. The butterfly plate can be coated according to the user's requirements, such as nylon or polytetrafluoroethylene.
8. The valve can be designed into flange connection and wafer connection.
9. The driving method can be manual, electric or pneumatic.
If butterfly valve is required to be used as flow control, the main thing is to correctly select the size and type of valve. The structure and principle of butterfly valve is especially suitable for making large-diameter valve. Butterfly valve is not only widely used in petroleum, gas, chemical industry, water treatment and other industries, but also in the cooling water system of thermal power station.
content is empty!