The turning center of the butterfly plate is on the center line of the valve body and the sealing face section of the butterfly plate. In closing, the ex-circle sealing face of the butterfly plate will extrude the valve seat made of synthetic rubber, generating elastic deformation on the seat to form an elastic force used as a sealing specific pressure so as to guarantee the tightness of the butterfly valve.
A butterfly valve is from a family of valves called quarter-turn valves. In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. When the valve is fully open, the disc is rotated a quarter turn so that it allows an almost unrestricted passage of the fluid. The valve may also be opened incrementally to throttle flow.
End Connection: RF, Wafer, Lug, etc
Nominal diameter: 2" - 60"（DN50 - DN1500）
Pressure range: Class 150 - 900（PN16 - PN100）
Working temperature: -196℃ - +550℃
Body material: Cast Steel, Stainless Steel, Ductile Iron, Carbon Steel, etc
Operation : Handle, Gear, Electric actuator, etc
Media: Water, Salt, Acid, Natural gas, Air, Mellow, Oil, etc
Type Available: Flanged type
Inspection & Testing: API 598
Basic Design: ANSI/AWWA C504
Materials Standard: Others on request
Face to Face Dimension: BS5155 Short, ISO5752 (Series 13), DIN 3202F16
Flanged End Dimension: DIN PN10/16/25, ANSI B16.1, BS4504, ISO PN10/16, JIS B2212/2213