Ball valve

Ball Valve

A ball valve is a type of valve used for controlling the flow of liquids or gases in a pipeline. It is characterized by a spherical disc, the part of the valve which controls the flow through it. The sphere has a hole, or port, through the middle so that when the port is in line with both ends of the valve, flow will occur. When the valve is closed, the hole is perpendicular to the ends of the valve, and flow is blocked.

History

The concept of the ball valve dates back to the early 19th century, but it was not until the invention of reliable sealing methods that they became a practical option for broad usage. The modern ball valve was developed and patented in 1957 by the BTR Industries of the United Kingdom.

Design and Operation

The basic design of a ball valve includes a sealing seat, a ball, stem, and handle. The ball is inserted into the passageway and the handle is attached to the stem of the ball. When the handle is turned, the ball rotates, aligning the hole in the ball with the opening in the passageway or blocking it off.

Ball valves can be designed to be operated manually with a handle or automated with an actuator. Actuators can be pneumatic, electric, or hydraulic.

Types of Ball Valves

There are several types of ball valves, each designed for specific applications and to handle different types of fluids or gases. These include:

• Full Port Ball Valve: This type of ball valve has an over-sized ball so that the hole in the ball is the same size as the pipeline resulting in lower friction loss.

• Reduced Port Ball Valve: Also known as a standard port ball valve, it has a smaller ball and a smaller port. This type of ball valve has a smaller flowpath, but offers more resistance to flow.

• V Port Ball Valve: This type of ball valve has a 'v' shaped ball or a 'v' shaped seat. This allows the orifice to be opened and closed in a more controlled manner with a closer to linear flow characteristic.

Applications

Ball valves are used in a variety of applications in many industries, including petroleum, chemical, pharmaceutical, and food and beverage. They are also commonly used in residential and commercial plumbing systems and in the water and wastewater treatment industry.

Advantages and Disadvantages

Ball valves have several advantages over other types of valves. They provide reliable sealing, have a low pressure drop, and can be used for both on/off and throttling services. However, they are not suitable for use where fine control of the valve is needed.

See Also

• Gate valve
• Globe valve
• Butterfly valve
• Check valve