1. Basic definition
Elastic seat butterfly valve is a valve that uses elastic sealing elements to cut off or regulate the medium. The core is that the valve seat is made of elastic materials such as rubber, polytetrafluoroethylene (PTFE) or polyetheretherketone (PEEK). The deformation ability of the elastic valve seat is used to compensate for the deviation of the sealing surface, which is suitable for pipeline systems containing suspended particles or corrosive media. It is commonly used in low and medium pressure, frequent opening and closing, and high hygiene requirements, such as water supply and drainage, food and pharmaceuticals.
2. Core structure
Elastic seat design
The valve seat is fixed to the inner wall of the valve body through a dovetail groove, a box structure or a pressure ring, forming an interference fit with the edge of the butterfly plate.
Some models use a "U"-shaped stainless steel sealing ring and an elastic material composite structure to enhance temperature resistance (-40℃~200℃) and wear resistance.
Butterfly plate and transmission mechanism
The butterfly plate is usually a centerline or single eccentric structure, and the surface can be welded with stainless steel or hard alloy to improve wear resistance.
The valve stem and butterfly plate adopt a through-rod design, which cooperates with the worm gear reducer to achieve precise opening and closing adjustment and reduce the operating torque.
3. Sealing principle and performance advantages
Sealing mechanism: When closed, the butterfly plate squeezes the elastic valve seat to deform and form a surface contact seal; the medium pressure further pushes the valve seat and the butterfly plate to fit together to achieve positive pressure shutoff.
Corrosion resistance: Elastic materials (such as EPDM, PTFE) can resist the erosion of acids, alkalis and organic solvents, extending the life of the valve.
Low flow resistance design: When fully open, the butterfly plate is parallel to the pipeline, the flow channel is straight, and the pressure loss is only 1/3 of the gate valve, which is suitable for large flow control.
4. Typical application scenarios
Municipal engineering: water plant network cutoff, sewage treatment plant impurity fluid control.
Industrial field: chemical corrosive medium transportation, food and pharmaceutical clean pipeline regulation.
Fire protection system: rapid opening and closing of fire water supply network and zone flow management.
5. Operation and selection points
Maintenance requirements: Regularly check the wear of the valve seat elastic material to avoid high temperature or strong oxidation environment causing rubber aging.
Selection suggestions:
Preferably choose composite elastic valve seats (such as PEEK + stainless steel) to take into account both temperature resistance and sealing performance.
The scene containing particle media needs to be matched with a worm gear reducer to achieve precise adjustment to prevent the butterfly plate from getting stuck.
The elastic seat butterfly valve has become an economical and reliable fluid control solution under medium and low pressure and complex media conditions through the adaptive sealing characteristics of elastic materials.
