The multi-layer soft laminated sealing ring is fixed on the valve plate. Compared with the traditional butterfly valve, this butterfly valve has high temperature resistance, light operation, no friction when opening and closing, and when closing, the torque of the transmission mechanism increases to compensate for the sealing, which improves the butterfly valve. The advantages of sealing performance and extended service life. However, this butterfly valve still has the following problems during its use:
Butterfly valve, as a component used to realize on-off and flow control of pipeline system, has been widely used in many fields such as petroleum, chemical industry, metallurgy, hydropower and so on. In the well-known butterfly valve technology, its sealing form mostly adopts a sealing structure, and the sealing material is rubber, polytetrafluoroethylene, etc. Due to the limitation of structural characteristics, it is not suitable for industries such as high temperature resistance, high pressure resistance, corrosion resistance, and wear resistance. An existing relatively advanced butterfly valve is a triple eccentric metal hard-sealed butterfly valve. The valve body and the valve seat are connected components, and the sealing surface layer of the valve seat is welded with temperature-resistant and corrosion-resistant alloy materials. The multi-layer soft laminated sealing ring is fixed on the valve plate. Compared with the traditional butterfly valve, this butterfly valve has high temperature resistance, light operation, no friction when opening and closing, and when closing, the torque of the transmission mechanism increases to compensate for the sealing, which improves the butterfly valve. The advantages of sealing performance and extended service life. However, this butterfly valve still has the following problems during its use:
1. Since the multi-layer soft and hard stacked sealing ring is fixed on the valve plate, when the valve plate is normally open, the medium will form a positive scouring on its sealing surface, and the soft sealing band in the metal sheet sandwich will directly affect the sealing performance after being scoured.
2. Due to structural conditions, this structure is not suitable for valves with a diameter below DN200, because the overall structure of the valve plate is too thick and the flow resistance is large.
3. Due to the principle of the triple eccentric structure, the sealing between the sealing surface of the valve plate and the valve seat depends on the torque of the transmission device to press the valve plate against the valve seat. In the positive flow state, the higher the medium pressure, the tighter the sealing extrusion. When the flow channel medium flows back, as the medium pressure increases, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the seal begins to leak.
The high-performance three-eccentric two-way hard sealing butterfly valve is characterized in that the valve seat sealing ring is composed of multiple layers of stainless steel sheets on both sides of a soft T-shaped sealing ring. The sealing surface of the valve plate and the valve seat is an oblique cone structure, and the surface of the oblique cone of the valve plate is welded with temperature-resistant and corrosion-resistant alloy materials; the spring fixed between the pressure plate of the adjusting ring and the adjusting bolt of the pressure plate are assembled together. This structure effectively compensates for the tolerance zone between the shaft sleeve and the valve body and the elastic deformation of the valve stem under the medium pressure, and solves the sealing problem of the valve in the two-way interchangeable medium conveying process.
The sealing ring is composed of a soft T-shaped multi-layer stainless steel sheet on both sides, which has the dual advantages of a metal hard seal and a soft seal, and has a sealing performance of zero leakage regardless of low temperature and high temperature.
