Introduction Of High Pressure Butterfly Valve

As a component used to realize the on-off of pipeline systems and control flow,Lined Butterfly Valve has been widely used in many fields such as chemical industry, petroleum, hydropower, mining, metallurgy, etc. In the known butterfly valve technology, its sealing form mostly adopts a sealing structure. Due to the limitation of structural characteristics, it is suitable for industries such as high temperature resistance, high pressure resistance, wear resistance, and corrosion resistance. A relatively advanced butterfly valve is a three-eccentric metal hard seal butterfly valve. The valve body and valve seat are connected components, and the valve seat sealing surface layer is welded with heat-resistant and corrosion-resistant alloy materials. The multi-layer soft stacking seal ring is fixed on the valve plate. Compared with the traditional butterfly valve, this butterfly valve has the advantages of high temperature resistance, easy operation, no friction when opening and closing, and the seal is compensated as the torque of the transmission mechanism increases when closing, which improves the sealing performance of the butterfly valve and prolongs its service life.

However, this butterfly valve still has the following problems during use:

1. Since the multi-layer soft and hard stacking seal ring is fixed on the valve plate, when the valve plate is normally open, the medium forms a positive scouring on its sealing surface. After the soft sealing belt in the metal sheet interlayer is scour, it directly affects the sealing performance.
2. Due to the limitation of structural conditions, this 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 three-eccentric structure, the seal between the sealing surface of the valve plate and the valve seat is pressed against the valve seat by the torque of the transmission device. In the positive flow state, the higher the medium pressure, the tighter the seal is squeezed. When the unit positive pressure between the valve plate and the valve seat is less than the medium pressure as the medium pressure increases during the reverse flow of the flow channel medium, the seal begins to leak.

High-performance high-pressure butterfly valve,

Featured in that: the valve seat sealing ring is composed of multiple layers of 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 cone structure, and the heat-resistant and corrosion-resistant alloy material is welded on the oblique cone surface of the valve plate; 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 band between the 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 in the process of two-way interchangeable medium transportation.
The high-pressure butterfly valve uses a soft T-shaped multi-layer stainless steel sheet on both sides to form a sealing ring, 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 test shows that in the positive flow state of the pool (the flow direction of the medium 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 effect of the medium pressure on the valve plate. When the positive medium pressure increases, the tighter the oblique cone surface of the valve plate and the sealing surface of the valve seat are squeezed, the better the sealing effect.

When in the countercurrent state, the seal 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 the valve seat is less than the medium pressure, the deformation energy stored by the spring of the adjusting ring after being loaded compensates for the tight pressure between the valve plate and the valve seat sealing surface and plays an automatic compensation role.

Therefore, unlike the existing technology, the utility model does not install a soft and hard multi-layer sealing ring on the valve plate, but is directly installed on the valve body. Adding an adjusting ring between the pressure plate and the valve seat is a very ideal two-way hard sealing method. It will replace gate valves, high-temperature butterfly valves and ball valves

1. Classification by structural form

(1) Center-sealed butterfly valve

(2) Single eccentric sealed coal valve

(3) Double eccentric sealed butterfly valve

(4) Triple eccentric sealed stomp valve

2. Classification by sealing surface material

(1) Soft-sealed butterfly valve.

1) The sealing pair is composed of non-metallic soft material against non-metallic soft material.

2) The sealing pair is composed of metal hard material against non-metallic soft material.

(2) Metal hard-sealed butterfly valve. The sealing pair is composed of metal hard material against metal hard material.

3. Classification by sealing form

(1) Forced-sealed butterfly valve

1) Elastic-sealed butterfly valve. The sealing pressure is generated by the elasticity of the valve seat or valve plate when the valve plate squeezes the valve seat when the valve is closed

2) External torque-sealed butterfly valve. The sealing pressure is generated by the torque applied to the valve shaft

(2) Pressurized sealed butterfly valve. The sealing pressure is generated by the pressure of the elastic sealing element on the valve seat or valve plate.

(3) Automatic sealing butterfly valve. The sealing pressure is automatically generated by the medium pressure.

4. Classification by working pressure

(1) Vacuum butterfly valve. Butterfly valve with working pressure lower than the standard reactor atmosphere.

(2) Low-pressure butterfly valve. Butterfly valve with nominal pressure PN <1.6MPa.

(3) Medium-pressure butterfly valve. Butterfly valve with nominal pressure PN of 2.5--6.4MPa.

(4) High-pressure butterfly valve. Butterfly valve with nominal pressure PN of 10.0--80.0MPa.

(5) Ultra-high-pressure butterfly valve. Butterfly valve with nominal pressure PN＞100MPa.

5. Classification by working temperature

(1) High-temperature butterfly valve. Butterfly valve with t＞450℃

(2) Medium-temperature butterfly valve. Butterfly valve with 120℃＜t＜450℃
(3) Normal temperature butterfly valve. Butterfly valve with -40℃＜t<；120℃
(4) Low temperature butterfly valve. Butterfly valve with -100℃＜t＜-40℃
(E) Ultra-low temperature butterfly valve. Butterfly valve with t＜-100℃
6. Classification by connection method
(1) Wafer type butterfly valve
(2) Flange type butterfly valve
(3) Lug type butterfly valve
(4) Welded butterfly valve