What is a Ball Valve?

Valves come in a wide range of types and sizes, each designed to control the flow of liquids or gases in different applications. At its core, a valve is a mechanical device that can be opened or closed to regulate flow—something as familiar as a kitchen faucet serves as a common example of everyday valve use. In this article, we'll focus on one specific and widely used type: the ball valve.

What is a Ball Valve?

A ball valve is a type of quarter-turn valve that uses a pivoting, perforated ball to control the flow of liquids or gases. When the hole in the ball is aligned with the flow path, media can pass through freely. Rotating the ball 90 degrees blocks the passage, stopping the flow entirely. The valve handle also acts as a clear visual indicator of the valve’s position:

Parallel to the pipeline = Open

Perpendicular to the pipeline = Closed

Ball valves are known for their durability and reliability, making them ideal for applications where simple on/off operation is required. They maintain a secure seal and perform consistently over numerous cycles, even after extended periods of disuse. While ball valves can technically be used to adjust flow by partially opening them, they are not ideal for precise throttling, where finer flow control is required. For such use cases, globe or gate valves may be more appropriate.

Key benefits of ball valves include:

Fast operation with quarter-turn actuation

Tight sealing with minimal leakage

Long service life and low maintenance

High resistance to wear and corrosion

Note: Ball valves should not be confused with ball-check valves, which are designed for one-way flow and prevent backflow in a system. Though similarly named, these valves serve different functions.

Differences Between One, Two, and Three Piece Ball Valves

Ball valves come in a variety of configurations to meet different needs for performance, maintenance, and cost. The three most common types are one-piece, two-piece, and three-piece ball valves. Understanding the differences between them is essential for selecting the right valve for your application.

One-Piece Ball Valves

One-piece ball valves are constructed from a single solid piece of material that includes both the valve body and the end connections. This integrated design reduces the number of joints, which in turn minimizes the potential for leaks. However, because the internal components must be inserted through one end, the valve typically has a reduced port that is smaller than the pipeline diameter. This can restrict flow and cause a pressure drop.

Servicing one-piece valves requires full removal from the system. Due to their low cost and maintenance difficulty, these valves are often replaced rather than repaired.

Benefits of One-Piece Ball Valves

Lower cost

Fewer joints and leak points

Disadvantages of One-Piece Ball Valves

Reduced port sizes

Pressure drop

Must be removed entirely for servicing

Two-Piece Ball Valves

Two-piece ball valves consist of two separate components, typically including the valve body and an end connector. These are joined using a bolted or threaded connection. This design allows for full port configurations, meaning the valve bore matches the pipe diameter, enabling higher flow rates with no pressure drop.

Two-piece valves are suitable for bidirectional flow shutoff. They offer a balance between cost and performance, being one of the most economical full-port valve options available.

Benefits of Two-Piece Ball Valves

Full port design for higher flow rates

Lower cost compared to other full-port options

Effective for bidirectional flow shutoff

Disadvantages of Two-Piece Ball Valves

Must be removed from the pipeline for maintenance

Higher cost than one-piece valves

Three-Piece Ball Valves

Three-piece ball valves are made of a central body and two end caps. The center section can be removed independently without disturbing the end connections, making it much easier to clean, inspect, or repair the valve while it remains installed in the system.

This feature makes three-piece valves especially valuable in industries such as pharmaceuticals and food and beverage processing, where regular cleaning and minimal downtime are essential. While the upfront cost is higher, the long-term serviceability makes them a smart investment for demanding applications.

Benefits of Three-Piece Ball Valves

Easy to clean and maintain in-line

Long-lasting with regular service

Ideal for sanitary and high-performance applications

Disadvantages of Three-Piece Ball Valves

Highest cost among the three types

Choosing the Right Ball Valve

Ball valves are available in many materials, configurations, and sizes. Choosing the correct valve depends on several factors including system pressure, media type, flow requirements, and maintenance expectations. If you need assistance in selecting the most suitable ball valve for your project, our team is ready to help.