BY CLOSURE MOTION
Butterfly / Disc Rotation
How the closing member moves relative to the seat — the geometry behind the family name.
Choosing Butterfly / Disc Rotation
A butterfly disc rotates within the flow passage. Its position relative to the shaft and seats distinguishes several design approaches. The motion also affects disc clearance, actuator torque and the usable control range.
What to include in the RFQ
- Request the disc/shaft/seat arrangement and permitted flow direction.
- Confirm mating-pipe and flange clearance through the full travel.
- Specify isolation or regulation and obtain the corresponding torque/capacity data.
Selection scenario
For a compact retrofit, check the open disc against the adjoining pipe and fitting before accepting the body dimensions. Then verify the actuator can meet the closing duty.
Common selection mismatch
Rotating-disc motion alone does not establish steam suitability, high-temperature sealing or end-of-line service.