Pneumatic flange eccentric butterfly valve adopts three eccentric multi-layer metal sealing structure, no mechanical wear, can achieve zero leakage, and has excellent two-way sealing function. It is used in petroleum, chemical, metallurgy, electric power, food, medicine, water supply and drainage, gas transportation. The best means of regulating the flow, shutting off or switching on the fluid on the pipes of different media.
Different materials can be used for water, sewage, seawater, air, steam, gas, flammable gas, corrosive media, oil and food. The maximum working temperature can reach 600 °C.
Due to the double eccentric sealing butterfly valve, the valve seat rotation axis forms a δ angle with the valve body passage axis. The eccentric result is seen from the A-A cross-sectional view of Figure B. When the three eccentric sealing butterfly valve is fully open, the disc sealing surface will completely disengage from the seat sealing surface and form a gap between the disc sealing surface and the valve body sealing surface. Clearance γ. It can be seen from Fig. C that the formation of the δ angle offset causes the long and short radius rotating discs to be large and small semi-circular, and the tangent of the disc sealing rotation trajectory forms a θ 1 angle and a θ2 angle with the valve seat sealing surface. When the butterfly valve is opened and closed, the sealing surface of the butterfly plate is gradually separated and gradually pressed. Thereby, the mechanical wear and abrasion between the two sealing faces of the butterfly valve opening and closing time are completely eliminated.
When the butterfly valve of this series is opened from 0°~90°, the sealing surface of the butterfly plate will leave the sealing surface of the valve seat immediately at the moment of opening. When the 90°~0° is closed, the sealing surface of the butterfly plate will contact and press. Tight seat sealing surface. It can be seen from Fig. C that, due to the formation of the angles θ 1 and θ 2 , when the butterfly valve is closed, the sealing specific pressure between the sealing faces of the sealing pair is generated by the driving torque applied to the valve stem. The utility model not only eliminates the reduction and disappearance of the sealing specific pressure caused by the elastic material aging, cold flow and elastic failure of the elastic valve seat in the conventional eccentric butterfly valve, but also can realize any adjustment of the sealing specific pressure by the change of the external driving torque. Therefore, the sealing performance of the triple eccentric sealing butterfly valve is improved.
Body material Carbon steel (WCB, WCC, LCB) Chromium-molybdenum steel (WC5, WC6, WC9) Alloy steel Stainless steel (CF3, CF8, CF3M, CF8M, ZG1Cr18Ni9Ti, ZG1Cr18Ni12Mo2Ti)
·Internal material stainless steel (1Cr13, 2Cr13, 1Cr18Ni9, 1Cr18Ni9Ti, 1Cr18Ni12Mo2Ti, 304, 316, 304L, 316L) Carbon steel Chromium-molybdenum steel Special steel
·Connection form Flange, clip, butt weld, lug pair
·Drive mode Manual, worm gear drive, electric, pneumatic, hydraulic, electro-hydraulic linkage, etc.
Main shape and connection connection size (flange type)