There are still the following problems in the working process of the rubber-lined butterfly valve.
One, multi-layer stacked sealing material installed on the butterfly plate, when the butterfly plate normally open work media will have a positive impact on the sealing surface of the butterfly valve, the soft sealing material in the metal sheet is scoured, will directly affect the sealing of the butterfly valve.
Second, restricted by the structural conditions of the butterfly valve, the overall structure of the butterfly plate must be too thick, large flow resistance, butterfly valve is not suitable for too small a diameter valve.
Third, the principle of rubber-lined butterfly valve: between the valve seat and the sealing surface is dependent on the torque action of the driving equipment to make the butterfly plate pressed to the valve seat, having the sealing. When working with the flow, the higher the pressure of the fluid medium the tighter the seal is squeezed, the better the seal; when working against the flow, the pressure of the medium will increase the positive pressure between the valve seat and the valve plate, when this pressure value is less than the pressure of the medium, the seal starts to leak.
High-performance rubber-lined butterfly valve features: the seat seal ring is composed of a T-shaped soft material seal ring plus multi-layer metal sheets on both sides.
Valve plate and seat sealing surface is oblique cone structure, in the oblique cone surface welded temperature-resistant, corrosion-resistant metal material, installed in the adjustment ring spring and the pressure plate on the screw assembly together, effectively compensate the difference between the valve body and the sleeve and the stem in the working pressure easy to produce elastic deformation, effectively solve the valve in the two-way flow of media transmission process exists in the seal leakage hidden trouble.
Adding multi-layered metal sheet composed of sealing ring on both sides of the soft T-shape, it has the double advantages of soft sealing and metal hard sealing, and has zero leakage sealing in both high and low temperature environments. When the downstream state, the sealing surface pressure generated is driven by the pressure of the pen and the medium pressure on the valve plate, the greater the pressure in the positive direction, the tighter the pressure on the sealing surface of the oblique cone and the valve seat, the better the sealing effect. When the counterflow state, the seal between the valve seat and the valve plate relies on the role of the rotation of the driving equipment to force the valve plate pressure to the valve seat. With the greater media pressure in the opposite direction, the positive pressure between the valve seat and the valve plate is lower than the media pressure, the compression deformation of the spring on the adjusting ring after being squeezed by the media carrier will make the tight pressure between the valve plate and the sealing surface of the valve seat become larger and start to self help compensation.