Ball valves are mechanical devices used to control the flow of fluids. They belong to the family of quarter-turn valves and are characterized by a spherical closure element (the ball) inside the valve body. The ball has a hole or port through its center, and when the valve is in the open position, the port allows fluid to flow through. Conversely, the port is rotated away in the closed position, blocking the flow.
Design and Structure
Ball valves consist of a spherical-shaped ball with a bore, a valve body, and an actuator (handle or lever). The ball is usually made of metal or other materials capable of withstanding the fluid’s pressure and corrosiveness.
The valve body has inlet and outlet ports, and the ball rotates within the body to control the flow. The handle or lever is connected to the ball and is used to turn the ball between the open and closed positions.
Functionality
Ball valves operate on a quarter-turn principle, meaning they only require a 90-degree rotation to change from fully open to fully closed or vice versa.
In the open position, the bore aligns with the pipe, allowing fluid to flow through. The bore is perpendicular to the pipe in the closed position, blocking the flow.
Types of Ball Valves
There are different types of ball valves, including:
- Two-way or Two-port Ball Valves: These have one inlet and one outlet and are used for on/off applications.
- Three-way or Three-port Ball Valves: Have three openings and can divert or mix flow between different pipes.
- Multi-port Ball Valves: These have more than three ports, allowing for complex flow configurations.
Materials
Ball valves are available in various materials such as brass, stainless steel, bronze, PVC, and other plastics. The material selection depends on factors like fluid type, temperature, and pressure requirements.
Applications
Ball valves are versatile and have applications in various industries, including water and wastewater treatment, oil and gas, petrochemical, chemical processing, HVAC systems, and general plumbing. They are suitable for both high-pressure and high-temperature applications.