Butterfly Valves

BUTTERFLY VALVES use what has been termed "a rotating disc" to reduce or shut off flow in a pipe. The disc or "wafer" pivots on a central axle connected to a handle or other control device outside the valve.
When the thin disc is positioned parallel to the direction of flow, fluids move freely around it. As the disc is rotated it takes up more and more of the diameter, choking off the flow. At 90 degrees, the disc seals against seats in the valve body to stop flow altogether.

This design is considered well suited to applications in which frequent throttling of flow is required. Butterfly valves are commonly specified in situations where high volumes of gases or liquids are moving under relatively low pressure.

Butterfly Valve Suppliers


Featured Products



  • Class 150: 2”-24” (including 2.5” & 5”)
  • Class 300: 2”-24” (including 2.5” & 5”)
  • Class 600: 3”-12”

ASME B16.34 Valves - Flanged, Threaded, and Welding End
ASME B16.5 Pipe Flanges and Flanged Fittings
ASME B16.10 Face to Face and End to End Dimensions of Valves
ANSI/FCI 70-2 Control Valve Seat Leakage
MSS SP-25 Standard Marking System for Valves
MSS SP-44 Steel Pipe Line Flanges
MSS SP-55 Quality Standards for Steel Castings
MSS SP-61 Pressure Testing of Steel Valves
MSS SP-68 High Pressure Butterfly Valves with Offset Design
MSS SP-96 Terminology for Valves and Fittings
API 598 Valve Inspection and Testing
API 607 Fire Test for Soft Seated Valves
API 609 Butterfly Valves: Double Flanged, Lug and Wafer Type
NSF/ANSI 61 (2”-24”, Stainless 215 & 230)
Drinking Water System Components - Health Effects
CE marked and documented valves that conform to the European Pressure Equipment Directive (PED) 97/23/EC are available in ASME class 150 & ASME class 300, both standard and fire-safe configurations.
CRN No. 0C17459.5CL

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