Butterfly Valve Valve body and valve seat of tri-eccentric hard sealing butterfly valve are combined component. Build up weld temperature, corrosion resistant alloy material on the valve seat sealing surface layer. Tri-eccentric: the centerline of shaft offsets centerline of the sealing surface, the shaft centerline is slightly deviated from centerline of the pipeline, and centerline of valve body sealing face (oblique circular cone) and centerline of pipeline form an angle of 尾. The multi-layer sealing ring is made of soft and hard laminated sheet metal. It has advantages of both of metal hard seal and soft seal. Sealing performance of zero leakage is guaranteed in low and high temperature. PRODUCT RANGE Sizes NPS 3 to NPS 80 Class 150 to Class 600 DESIGN FEATURES Wafer, Lugged, RF or BW MATERIALS Available in Casting (A216 WCB, WC6, WC9, A350 LCB, A351 CF8, CF8M, CF3, CF3M, A995 4A, A995 5A, A995 6A), Alloy 20, Monel, Inconel, Hastelloy DESIGN STANDARD Design manufacture according to API 609 Face-to-face according to ASME B16.10 End Connection according to ASME B16.5 or B16.47 (Wafer, Lugged, Flange), ASME B16.25 (BW) Test inspection according to API 598 Also available per NACE MR-0175, NACE MR-0103Butterfly Valve website:http://www.fluid-valvestech.com/butterfly-valve/