The Ball valve has a sphere-shaped disc. This is the part of the valve which controls the flow through it. The sphere has a hole, or opening, through the middle so that when the opening is in line with both ends of the valve, flow is permitted. When the valve is closed, the opening is at right angles to the ends of the valve, and flow is suspended. The ball valve, together with the butterfly valve and plug valve, are part of the group of quarter turn valves.

Ball valves are probably the best selection for shutoff applications. They are often preferred to globe valves and gate valves for this function.

Ball valves are extensively used in Oil Refining, Petroleum, Natural gas production and Refining industries because they are very adaptable and can handle very high pressures and temperatures. They are easy to repair and operate.

The body of ball valves can be made of metal, plastic or metal with a ceramic center. The valve ball can be chrome plated to make it more hard-wearing.

Types of ball valves:

There are generally five styles of ball valves: single body, three piece body, split body, top entry, and welded.

There are generally three types of ’full bore’ ball valves:

• A ‘full bore’ ball valve has a larger valve ball so that the hole in the ball is the same size as the pipeline which results in a lower friction loss. The flow is unobstructed, but the valve is larger. ‘Full bore’ ball valves are typically used in pipelines such those in Oil refining, Petroleum, Natural gas production and Refining industries.
• In ‘reduced bore’ ball valves, the stream through the valve is one pipe size smaller than the valve's pipe size. This means that the flow region becomes less than the pipe with the flow release remaining constant.
•  A ‘V port’ ball valve has either a 'v' shaped valve ball or a 'v' shaped seat. This permits the oral cavity to be opened and closed in a more proscribed manner. When the valve is in the closed position and then opened, the small end of the 'v' is opened first allowing a uniform flow control in this phase. This type of design generally involves a more sturdy construction which can withstand higher velocities of fluids which would damage a standard valve type.

A Trunnion ball valve has a mechanical means of fixing the ball at the top and at the bottom. This design is usually applied on larger and higher pressure valves.

Ball valves are fitted with an actuator which can be either pneumatically or motor operated. These valves can be used to turn on or turn off the flow, or indeed to control the flow. A pneumatic flow control valve is also fitted with a locater which alters the control signal into the actuator position to open the valve.

‘Three-way’ ball valves have an L- or T-shaped hole through the middle.

‘Multi-port’ ball valves with 4 directions, or more, can also be acquired for special applications. The ‘4-way valve’ has two L-shaped ports in the valve ball which do not interconnect. These are also sometimes referred to as "×" ports.

Ball valves in sizes up to 2 inch usually come in single piece, two or three piece designs. One piece ball valves are nearly always of the reduced bore variety. Two piece ball valves are usually slightly smaller (or standard) bore varieties.

The 3 piece design permits the center part of the ball valve containing the valve ball, the stem & seats to be easily withdrawn from the pipeline. This enables efficient cleaning of any deposited sediments and the replacement of seats and gland packings. It also makes it possible to polish out any small scratches on the valve ball without removing the pipes from the valve body.

Ball Valves can be made from materials such as: Carbon steels - stainless steel - Inconel® - High Alloys - Titanium - Monels ® - Nitronic 60 - Stellite - Carpenter 20 - Duplex stainless steels and other nickel based alloys. These are specifically designed for strength, resilience and best possible performance for the flow of any industrial liquid as those found in the Oil refining, Petroleum, Natural gas production and Refining industries.