Why can triple eccentric hard seal butterfly valve be widely used
The triple eccentric hard-sealed butterfly valve is widely used in metallurgy, electric power, petrochemical, water supply and drainage, and municipal construction and other industrial pipelines with a medium temperature of 425 ℃ or less to adjust flow and cut off fluid.
In the previous article, we introduced to you the sealing principles of various eccentric butterfly valves. As a component used to realize the on-off and flow control of the pipeline system, the butterfly valve has been obtained in many fields such as petroleum, chemical industry, metallurgy, hydropower, etc. Very widely used. Single eccentric butterfly valve and double eccentric butterfly valve are not suitable for high temperature, high pressure, corrosion resistance, wear resistance and other industries due to structural characteristics. Triple eccentric metal hard seal butterfly valve, the valve body and 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, is easy to operate, and has no friction when opening and closing. 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.
The triple eccentric metal hard seal butterfly valve is characterized by:
The valve seat sealing ring is composed of multiple layers of stainless steel sheets on both sides of the 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 adjusting ring pressure plate 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.
The test proves that in the positive flow state of the pool (the flow direction of the medium is the same as the rotation direction of the butterfly plate), the pressure of the sealing surface is produced by the torque of the transmission device and the action of the medium pressure on the valve plate. When the positive medium pressure increases, the tighter the oblique cone surface of the valve plate and the sealing surface of the valve seat are pressed, the better the sealing effect. When in the reverse flow state, the seal between the valve plate and the valve seat depends on the torque of the drive device to press the valve plate against the valve seat. With the increase of the reverse medium pressure, when the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the deformation energy stored by the spring of the adjusting ring after being loaded compensates for the tight pressure of the sealing surface of the valve plate and the valve seat Play the role of automatic compensation. Therefore, the utility model does not install soft and hard multilayer sealing rings on the valve plate as in the prior art, but directly installs on the valve body. The addition of an adjustment ring between the pressure plate and the valve seat is a very ideal two-way hard sealing method. . It can replace gate valves, globe valves and ball valves.
