Design Standard: API 609
Fire safe: API 607/6FA
Pressure-temperature Ratings: ASME B16.34
Size Range: 2” to 80”
Pressure Range: Class 150 to 600
End Connections: Wafer, Lug, Flanged RF, RTJ, Butt Weld
Flanged End Dimensions: ASME B16.5 (≤24”), ASME B16.47 Series A or B (>24”)
Butt Weld End Dimensions: ASME B16.25 Face to Face
Face to Face Dimensions: API 609
Inspection and Testing: API 598
Body Materials: WCB, CF8, CF3, CF3M, CF8M, A995 4A, 5A, 6A, C95800, INCONEL 625, INCONEL 825, MONEL, WC6, WC9.
Sealing Material: Laminated disc seal, full metal ring, PTFE
Packing materials: graphite, graphite with inconel wire, PTFE
Temperature: -196 to 425℃
Triple offset butterfly valve is a quarter turn valve, but the sealing member is not the disc, but a sealing ring installed on the disc. Similar as ball valves, triple offset butterfly valves are used as on-off valves, and not suitable for capacity control applications. Because of the triple offset design, there’s almost no friction between the disc sealing ring and the seat while opening and closing, thus to improve the valve lifetime. The disc is still kept in the valve center even at the opening position, the disc will have great flow resistance to the medium, so normally triple offset valves is used for pipeline above 8”, because for small sizes, the flow power loss is big. Compared with ball and gate globe valves, butterfly valves is much more economical, because it’s short face to face length. But there’s also a limitation for triple offset butterfly valves, normally the application pressure is not so high. Triple offset butterfly valve is widely used in oil & gas, petrochemical, power plant, water treatment, etc.