At present, butterfly valve as a kind of pipeline system used to achieve the flow control of parts, has been in the petroleum, chemical, metallurgy, hydropower and many other fields are extremely widely used. In the known butterfly valve technology, the sealing form mostly adopts sealing structure, and the sealing material is rubber, PTFE, etc. Due to the limitations of structural features, it is not suitable for high temperature resistance, high pressure and corrosion resistance, anti-wear and other industries. A more advanced butterfly valve is a triple eccentric metal hard seal butterfly valve, the valve body and the valve seat for the conjoined components, seat sealing surface layer welded temperature and corrosion resistant alloy materials. This butterfly valve has the advantages of high temperature resistance, light operation, non-friction opening and closing, and compensation sealing with the increase of torque of the transmission mechanism when closing, which improves the sealing performance and extends the service life of the butterfly valve compared with the traditional butterfly valve. However, this butterfly valve still has the following problems in the process of use.
First, because of the multi-layer soft and hard stacked seal ring fixed on the valve plate, when the valve plate is normally open state media to form a frontal scouring of its sealing surface, the metal sheet sandwich in the soft sealing belt by the scouring, directly affect the sealing performance.
Second, the structural conditions of the structure is not adapted to do the diameter DN200 below the valve, the reason is that the overall structure of the valve plate is too thick, large flow resistance.
Third, because of the principle of triple eccentric structure, the sealing surface of the valve plate and the valve seat is sealed by the torque of the transmission device to make the valve plate pressed to the valve seat. When the positive flow state, the higher the pressure of the medium the tighter the seal squeeze. When the flow channel media counterflow with the increase in media pressure between the valve plate and the valve seat unit positive pressure is less than the media pressure, the seal began to leak.
The purpose of the utility model is to provide a zero leakage, flexible opening and closing, long service life, high temperature resistance, high pressure, corrosion resistance, wide range of application of anti-wear high-performance three-eccentric two-way hard seal butterfly valve.
High performance three eccentric two-way hard seal butterfly valve, characterized in that: the seat seal ring by the soft T-shaped sealing ring on both sides of the multi-layer stainless steel sheet composition. The sealing surface of the valve plate and the valve seat is oblique cone structure, in the valve plate oblique cone surface welded temperature and corrosion resistant alloy material; fixed in the adjustment ring between the pressure plate spring and the pressure plate on the adjustment bolt assembly together structure. This structure effectively compensates for the tolerance zone between the sleeve and the valve body and the elastic deformation of the valve stem under medium pressure, solving the sealing problem that exists in the valve during the two-way interchangeable medium transmission.
The use of soft T-shaped multi-layer stainless steel sheet on both sides of the seal ring, with the dual advantages of metal hard seal and soft seal, regardless of the low and high temperature conditions, have zero leakage sealing performance.
The test proves that when the pool is in positive flow (the direction of media flow is the same as the direction of butterfly plate rotation), the pressure on the sealing surface is generated by the torque of the transmission device and the action of media pressure on the valve plate. When the positive medium pressure increases, the tighter the valve plate oblique cone surface is extruded with the sealing surface of the valve seat, the better the sealing effect.
When the reverse flow state, the seal between the valve plate and the valve seat relies on the torque of the drive device to press the valve plate to the valve seat. With the increase of the reverse medium pressure, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the spring of the adjusting ring can compensate for the deformation stored after the load of the valve plate and the tight pressure of the sealing surface of the valve seat to play a role in automatic compensation. Therefore, the utility model is not like the existing technology, the installation of soft and hard multi-layer seal on the valve plate, but directly installed on the valve body, the pressure plate and the valve seat in the middle of the additional adjustment ring is very ideal two-way hard seal mode. It will replace the gate valve, globe valve and ball valve.