Troubleshooting methods for electric hard sealed butterfly valves
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2014-09-23
1、 Due to the multi-layer soft and hard laminated sealing ring fixed on the valve plate, when the water pump valve plate is in a normally open state, the medium forms a positive flushing on its sealing surface, and the soft sealing belt in the metal interlayer is directly affected by the flushing, which directly affects the sealing performance.
2、 Due to structural limitations, this structure is not suitable for valves with a diameter below DN200, as the overall structure of the valve plate is too thick and the flow resistance is large.
3、 Due to the principle of a three eccentric structure, the sealing between the sealing surface of the valve plate and the valve seat relies on the torque of the transmission device to press the valve plate towards the valve seat. When in a positive flow state, the higher the medium pressure, the tighter the sealing compression. When the medium in the flow channel is in reverse flow, as the pressure of the medium increases, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, and the seal begins to leak.
The high-performance three eccentric hard sealing butterfly valve is characterized in that the sealing ring of the water pump valve seat is composed of multiple layers of stainless steel sheets on both sides of the soft T-shaped sealing ring.
The sealing surface between the valve plate and the valve seat is of an inclined conical structure, and temperature and corrosion resistant alloy materials are deposited on the inclined conical surface of the valve plate; The structure where the spring fixed between the adjusting ring pressure plate and the adjusting bolt on the pressure plate are assembled together.
This structure effectively compensates for the tolerance zone between the shaft sleeve and the valve body, as well as the elastic deformation of the valve stem under medium pressure, solving the sealing problem of the valve during the bidirectional exchange medium transportation process.
The sealing ring is composed of multiple layers of stainless steel sheets on both sides of a soft T-shape, which has the dual advantages of metal hard sealing and soft sealing. It has zero leakage sealing performance regardless of low or high temperature conditions.
The experiment proves that when the pool is in a positive flow state (the direction of medium 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 effect of medium pressure on the valve plate. When the positive medium pressure increases, the tighter the compression between the inclined conical surface of the valve plate and the sealing surface of the valve seat, the better the sealing effect.
When in a countercurrent state, the sealing between the valve plate and the valve seat is pressed against the valve seat by the torque of the driving device. As the reverse medium pressure increases, when the unit positive pressure between the valve plate and valve seat is less than the medium pressure, the deformation energy stored by the adjusting ring spring after being loaded compensates for the tight pressure on the sealing surface between the valve plate and valve seat, playing an automatic compensation role.
Therefore, unlike existing technologies, this utility model does not install soft and hard multi-layer sealing rings on the valve plate, but directly on the valve body. Adding an adjustment ring between the pressure plate and the valve seat is a very ideal bidirectional hard sealing method. It will replace gate valves and ball valves.
