Knowledge

What is a welded butterfly valve?



Features:
       1. It is designed and manufactured with a new type of structure welded by midline discs and short structure steel plates. It has a compact structure, light weight, easy installation, small flow resistance, large circulation, avoiding the influence of high temperature expansion, and easy operation.
       2, there is no connecting rod, bolts, etc., reliable, long service life. Can be installed in multiple stations, free from media flow.
       Uses: The butterfly valve is a non-closed butterfly valve, suitable for building materials, metallurgy, mining, electricity and other production process medium temperature ≤ 300 °C nominal pressure of 0.1Mpa pipeline, to connect, open and close or adjust the amount of medium.
       Structural features: The butterfly valve is designed and manufactured with a new type of structure in which the midline disc plate and short structure steel plate are welded. The structure is compact, light in weight, easy to install, small in flow resistance, large in circulation, avoiding the influence of high temperature expansion, and easy to operate. There are no connecting rods, bolts, etc. in the body, reliable operation and long service life. Can be installed in multiple stations without being affected by the flow of media.
       Working principle: The welding butterfly valve mechanism can make the disc rotate freely within 90° to achieve the purpose of opening and closing or adjusting the flow of medium.
       At present, lining fluorine butterfly valve and lining rubber butterfly valve, as a kind of component used to realize the on-off and flow control of pipeline system, have been applied more frequently in petroleum, chemical industry, metallurgy, hydropower and many other fields. In the known butterfly valve technology, the sealing structure is mostly a sealed structure, and the sealing material is rubber, PTFE, and the like. Due to structural characteristics, it is not suitable for high temperature, high pressure, corrosion and wear resistance industries. The existing one of the more advanced butterfly valves is a three-eccentric metal hard-seal butterfly valve. The valve body and the valve seat are connected components, and the valve seat sealing surface layer is surfacing with temperature-resistant and corrosion-resistant alloy materials. The multi-layer soft stack seal is fixed on the valve plate. Compared with the traditional butterfly valve, this type of butterfly valve has high temperature resistance, easy operation, no friction when opening and closing, and the seal is increased when the torque of the transmission mechanism is increased during closing. The sealing performance and the advantages of prolonged service life.
        Use issue:
        1. Because the multi-layer soft and hard stack seal is fixed on the valve plate, when the valve plate is always open, the media forms a frontal flush against its sealing surface. After the soft seal tape in the metal plate interlayer is washed, it directly affects the sealing performance.
        2, by the structural constraints of the structure is not suitable for the following diameter DN200 valves, because the overall structure of the valve plate is too thick, large flow resistance.
        3, due to the principle of lined rubber butterfly valve, the seal between the valve plate sealing surface and the valve seat is to rely on the torque of the transmission device to press the valve plate to the valve seat. In the normal flow state, the higher the medium pressure, the tighter the seal extrusion. When the medium of the flow passage is reversed, the seal begins to leak when the positive pressure between the valve plate and the valve seat is smaller than the pressure of the medium as the pressure of the medium increases.
        4, high-welded butterfly valve, characterized in that: the valve seat seal ring consists of soft T-shaped seal ring on both sides of multi-layer stainless steel sheet.
       The sealing surface of the valve plate and the valve seat is an inclined conical structure, and a temperature-resistant, corrosion-resistant alloy material is surfacing on the oblique conical surface of the valve plate; a spring fixed between the adjusting ring pressure plate and the adjusting bolt of the pressure plate are assembled together. This structure effectively compensates the tolerance band between the 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 interchanged medium conveying process.