The Versatile Butterfly Valve Have Efficient Flow Regulation and Isolation
The Versatile Butterfly Valve Have Efficient Flow Regulation and Isolation
The Versatile Butterfly Valve Have Efficient Flow Regulation & Isolation
A butterfly valve is a type of quarter-turn valve used to regulate or isolate the flow of fluid in a pipeline. It operates by rotating a disc-shaped element (the "butterfly") within the valve body. When the disc is parallel to the flow, the valve is fully open; when perpendicular, it is closed.
Principle of operation
Butterfly valves operate similarly to ball valves, allowing quick shut-off. They are generally favored for being lower cost and lighter weight than other valves, requiring less support. The disc is positioned in the pipe center, with a rod connecting it to an external actuator. Rotating the actuator turns the disc parallel or perpendicular to the flow. Unlike a ball valve, the disc is always within the flow, inducing a pressure drop even when open.
As quarter-turn valves, they are fully open or closed when the disc rotates a quarter turn. When closed, the disc blocks the passageway; when fully open, it allows nearly unrestricted flow. They can also throttle flow incrementally.
Different types adapt to various pressures:
- Zero-offset butterfly valves use rubber flexibility and have the lowest pressure rating.
- High-performance double-offset butterfly valves (for higher pressures) have two offsets: disc seat/body seal centerline, and bore centerline. This creates a cam action reducing friction and wear.
- Triple-offset butterfly valves (best for high pressure) offset the disc-seat contact axis, virtually eliminating sliding contact. Their metal seat is machined for bubble-tight shut-off.
Types
- Concentric butterfly valves – this type of valve has a resilient rubber seat with a metal disc.
- Doubly-eccentric butterfly valves (high-performance butterfly valves or double-offset butterfly valves) – different type of materials is used for seat and disc.
- Triply-eccentric butterfly valves (triple-offset butterfly valves) – the seats are either laminated or solid metal seat design.
- Butterfly valve with actuator electric valve - An electrically actuated butterfly valve is a quarter-turn valve controlled by an electric motor. It offers fast and precise flow regulation, remote operation, and versatility for various applications.
Wafer-style butterfly valve
Wafer-style butterfly valves provide a tight, bi-directional seal against pressure to prevent backflow in unidirectional systems, using precision-machined seals and flat faces. However, they offer limited flow control, may cause a greater pressure drop, and are prone to clogging.
