Butterfly valves are versatile flow control devices used across industrial processing lines and building services. Their compact, lightweight design and excellent shutoff performance make them ideal for both throttling and on/off applications. Wafer butterfly valves are a streamlined and economical style optimized for space-constrained piping systems.
- Wafer butterflies are a simple two-piece design that inserts between pipe flanges.
- The circular disc rotates to regulate flow, with resilient sealing against the body interior.
- Their uncomplicated construction suits high cycling, non-critical low-pressure applications.
Let’s review wafer butterfly in detail!
Defining the Wafer Butterfly Valve
Butterfly valves consist of a metal disc that pivots in the flow stream to control passage through the pipe. In the open position, the disc is rotated parallel to the flow, allowing an unobstructed conduit. When closed, the disc seats against the body interior to provide shutoff.
The wafer style sandwiches between two mating pipe flanges, effectively creating a “wafer” thin body profile. It forms a lightweight, compact inline flow control solution without extended neck portions or mounting feet.
Main Components and Construction
Wafer butterfly valves have just two primary components – the body and the disc:
- Body: Consists of a one-piece casting with raised internal surfaces for the disc to seal against in the closed position. Common materials are ductile iron, aluminum bronze, stainless steel or engineered plastics.
- Disc: A contoured metal disc serves as the flow control element. It may have a stainless steel edge for improved shutoff and longer service life.
The shaft runs through the disc centerline and utilizes bushings or bearings on both sides. It connects to the actuator, allowing manual, pneumatic, hydraulic or automated operation to rotate the disc open and closed.
A resilient liner seals the disc edge against the body seat. Materials like EPDM, NBR, and PTFE provide tight shutoff while allowing the metal disc to glide smoothly. The liner may also cover the disc face for soft sealing in bi-directional dead-end applications.
Operating Principle and Flow Control
In operation, the butterfly valve wafer type gear operated by rotating disc cuts across the complete cross-section of pipe flow. When fully open, minimal pressure drop occurs as flow passes the slim disc edge. Closing the valve gradually restricts flow area, building up inline pressure and providing precise throttling capability.
The contoured disc produces an eccentric rotary motion. As the disc approaches the closed position, its approaching edge meets the seat first. This forms a sealing line across the disc span, effectively shutting off flow. The cast iron wafer butterfly valve disc stays in contact with the seat while closed, preventing flow leakage even as pressure builds against the disc.
Benefits and Applications of Wafer Butterfly Valves
Wafer butterflies offer:
- Compact, lightweight inline installation
- Low rotational torque requirements
- High capacity flow regulation
- Tight shutoff with complete isolation possible
- Fast operation for on/off duty
- Streamlined maintenance without bolted body joint
These capabilities make wafer butterfly valves ideal for non-critical industrial applications such as:
- Water and wastewater treatment
- HVAC and large building systems
- General chemical processing
- Water distribution and irrigation networks
- Mine dewatering
- Agricultural operations
- Pulp and paper production
Conclusion
Wafer butterfly valves deliver versatile throttling and on/off functionality in a simplified two-piece sandwich body design. Their uncomplicated construction and small footprint suit tight installation spaces across processing industries.
With expertise in selecting optimal materials and designs, Xintai Valve provides long-lasting wafer butterfly valves for maximum productivity and reliability. Contact us to discuss implementing wafer valve solutions for your application needs.
