Wedge two-way metal sealing butterfly valve structure characteristics

I. Preface In order to meet the high temperature, low temperature, strong corrosion, strong erosion and long life and other industrial requirements, metal sealing butterfly valve valve in recent years become one of the fastest growing varieties. In some special occasions on the sealing of the metal hard sealing butterfly valve put forward higher requirements, must be bi-directional pressure. At present, the domestic and foreign markets adopt the double eccentric and three-dimensional eccentric sealing principle mostly in the hard seal medium valve. Both of the two sealing structures are in a positive flow state and the sealing effect is better. When the medium is in the countercurrent state, The pressure on the disc eccentric moment, is not conducive to the valve seal. On the other hand, due to machining gap problem, the reverse sealing performance is greatly reduced. Second, the structure Wedge two-way metal seal butterfly valve is based on the open and close the valve automatically grinding seal compensation theory as the basis, combined with the gate valve, can push the ball valve, orbital ball valve and other product features designed from the structure. Play like the positioning pin to ensure that the disc will not be discounted by the role of gravity butterfly, but also set the adjustment block at the end of the lower stem to ensure the disc position is fixed. Throughout the process of opening and closing, the stem relies on the dovetail contraction mechanism, the helical lifting track to complete the vertical linear motion, and the butterfly plate to rely on the dovetail contraction mechanism, spiral lifting track to complete the center contraction from the seat, in this process the sealing surface Using the first open after the way to ensure that from the seal to the instantaneous from the valve seat always maintain the gap, there is no friction, so the valve sealing surface without wear and tear, long life, small torque. And because of the stem of the wedge-shaped block and dovetail groove effect on the valve increased forced sealing force, increasing the pressure ratio of the seal, to achieve two-way seal. Combined ring can be based on user needs using PTFE as the main material processing and molding of soft ring, made of stainless steel and flexible graphite laminated multi-layer seal or the whole stainless steel metal seals and other forms . By virtue of the symmetrical left and right disc plates, they are sealed with the left and right valve seats which are symmetrically arranged in the valve body, respectively. There is no eccentricity to form two seals, thereby greatly improving the reliability of the sealing performance and bidirectional zero leakage of the disc plate. This product can also add a water seal in the middle of the valve body, which can be in the event of an emergency or pipeline access to the cavity water, safe and a dual role. Wedge-type two-way metal butterfly valve butterfly valve with a full cone sealing surface structure, the valve can be achieved during the valve sealing surface and valve sealing surface constantly grinding, self-correction and improve the service life. Operating Procedures The operating torque is reduced because the media pressure helps to open the valve. Third, the conclusion wedge two-way metal sealing butterfly valve novel and unique sealing structure, double disc with two-way sealing function, it is more suitable for high temperature and high pressure conditions. Valve processing technology is good, low cost of design and manufacturing, is a high-tech parameters to adapt to high-performance industrial transmission system of the hard seal butterfly valve.