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Precautions in the use of fluorine-lined butterfly valves

Mar 27, 2022

The butterfly plate of the fluorine-lined butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical channel of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When it rotates to 90°, the valve is fully open. So what problems exist in the use of fluorine-lined butterfly valves?

1. Since the multi-layer soft and hard laminated sealing ring is fixed on the valve plate, when the valve plate is normally open, the medium forms a positive scouring on its sealing surface, and the soft sealing belt in the metal sheet interlayer is scoured, which directly affects the sealing performance.

2. Restricted by structural conditions, the structure is not suitable for valves with a diameter below DN200, because the overall structure of the valve plate is too thick and the flow resistance is large.

3. Due to the principle of the rubber-lined butterfly valve, 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 to the valve seat. In the positive flow state, the higher the medium pressure of the pinch valve, the fluorine-lined valve, and the exhaust valve, the tighter the seal squeezes. When the medium in the flow channel flows back, the seal begins to leak when the unit positive pressure between the valve plate and the valve seat is less than the medium pressure as the medium pressure increases.

Fourth, the high-performance fluorine-lined butterfly valve is characterized in that: the valve seat sealing ring is composed of multi-layer stainless steel sheets on both sides of the soft T-shaped sealing ring.

The sealing surface of the valve plate and the valve seat is an oblique conical structure, and the temperature-resistant and corrosion-resistant alloy materials are surfacing on the oblique conical surface of the valve plate; the spring fixed between the adjustment ring pressure plates and the adjustment bolts on the pressure plate are assembled together. This structure effectively compensates the tolerance zone between the shaft 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 during the two-way exchange of medium conveying.

The sealing ring is composed of multi-layer stainless steel sheets on both sides of the soft T-shaped, which has the dual advantages of metal hard sealing and soft sealing, and has zero leakage sealing performance under low temperature and high temperature conditions. The test proves that when the pool is in a positive flow state (the direction of medium flow is the same as the rotation direction of the butterfly plate), the pressure on the sealing surface is generated by the torque of the transmission device and the action of the medium pressure on the valve plate. When the positive medium pressure increases, the tighter the oblique conical surface of the valve plate and the sealing surface of the valve seat are, the better the sealing effect will be.


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