Flow through the different position of Butterfly valve.

Aim

Flow nature when the butterfly valve at a different position and create an obstruction in flow.

Introduction

A valve consisting of a rotating circular plate or a pair of hinged semicircular plates, attached to a transverse spindle and mounted inside a pipe in order to regulate or prevent flow. Butterfly valves have a short circular body, a round disc, metal-to-metal or soft seats, top and bottom shaft bearings, and a stuffing box. The construction of a Butterfly valve body varies. A commonly used design is the wafer type that fits between two flanges.

Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves are generally favored because they cost less than other valve designs, and are lighter weight so they need less support. The disc is positioned in the center of the pipe. A rod passes through the disc to an actuator on the outside of the valve. Rotating the actuator turns the disc either parallel or perpendicular to the flow. Unlike a ball valve, the disc is always present within the flow, so it induces a pressure drop, even when open.

Types

1. Concentric butterfly valves – this type of valve has a resilient rubber seat with a metal disc.
2. Doubly-eccentric butterfly valves (high-performance butterfly valves or double-offset butterfly valves) – a different type of materials are used for seat and disc.
3. Triply-eccentric butterfly valves (triple-offset butterfly valves) – the seats are either laminated or solid metal seat design.

StreamLine contours when 30 Degree valve position

StreamLine contours when 60 Degree valve position

StreamLine contours when 90 Degree valve position

Conclusion

• High velocity is observed when the valve at 30 degrees compared to other valve position.
• When the valve position is 30-degree after the valve fluid recirculation or low-pressure region.
• When the valve position is 60-degree vortex generation and swirl inflow.
• When the valve position is 90-degree flow is normal.
• high and low-pressure zone creation at the valve.