How does a wafer valve work?

A wafer valve, also known as a butterfly valve, is a type of quarter-turn valve that is commonly used to control the flow of fluids in various industrial applications. Here's an overview of how a wafer valve works:

Components of a Wafer Valve:
Body:

The main body of the wafer valve is typically thin and disc-shaped, resembling a wafer. This design allows the valve to be lightweight and easy to install between flanges.
Disc:

The disc, or butterfly, is a flat or slightly conical plate that is mounted in the center of the valve body. It is connected to a shaft that passes through the center of the valve.
Shaft:

The shaft is the central rotating component that connects the disc to the actuator. When the shaft rotates, it causes the disc to turn, regulating the flow of the fluid.
Actuator:

The actuator is the mechanism responsible for rotating the shaft and, consequently, controlling the position of the disc. Actuators can be manual (hand-operated), electric, pneumatic, or hydraulic, depending on the application.
Operation:
Open Position:

In the open position, the disc is turned parallel to the flow direction. This allows for maximum flow through the valve. The valve is fully open when the disc is perpendicular to the pipe.
Closed Position:

In the closed position, the disc is turned to be parallel to the pipe, obstructing the flow. The valve is fully closed when the disc is perpendicular to the pipe.
Intermediate Positions:

The wafer valve can also be positioned at any intermediate angle between fully open and fully closed to regulate the flow at different levels.
Working Principle:
Quarter-Turn Rotation:

The operation of a wafer valve is based on a quarter-turn rotation of the disc. When the actuator is engaged, it rotates the shaft, which, in turn, rotates the disc. The rotation of the disc controls the flow by either allowing a straight passage for the fluid (fully open) or blocking it (fully closed).
Low Pressure Drop:

Wafer valves are known for their low pressure drop compared to some other types of valves. In the fully open position, the disc does not obstruct the flow significantly, reducing pressure loss.
Quick Operation:

The quarter-turn operation of the wafer valve allows for quick opening and closing, making it suitable for applications where rapid control of flow is required.
Compact Design:

The wafer valve's compact and lightweight design, with no extended stems or bonnets, makes it easy to install between flanges, saving space and reducing overall weight.
Bi-Directional Flow:

Most wafer valves are designed to handle flow in both directions, making them versatile for various applications.