Ball Valve

A ball valve is a type of pipe vale that opens by turning a handle attached to a ball inside the valve. They are used for quick shut off and low emission application. They are durable and can work to achieve perfect shutoff or closure even after years of not-in- use. They are always an excellent choice for shutoff applications. 

They are sometimes preferred to globe valves and gate valves for this purpose. Although, ball valves cannot offer the fine control that may be required in throttling applications but are still sometimes used for this purpose.

Styles of ball valves:
Ball valves have three general body styles. They are as follows:

• Split body
  • One-piece
  • Two-piece
  • Three-piece
  • Flanged body
• Top entry
• Welded

Each of these body styles have specific advantages depending upon the requirements of the given application.

Types of ball valves:
There are three general types of ball valves:

• Full port: This has an over sized ball so that the hole in the ball is of the same size as the pipeline thereby resulting in lower friction loss. The valve is larger and the flow is unrestricted.
• Standard port: This has a smaller ball and hence a smaller port. This is less expensive. Flow through this type of butterfly valve is one pipe size smaller than the valve’s pipe size which results in slightly restricted flow.
• Reduced port: Here the flow through the valve is two pipe sizes smaller than the valve’s pipe size which also results in restricted flow.

Salient features of ball valve: 

Ball valves have certain characteristics which make them superior to other valves. They are as follows:

• Positive shut off
• Quick in action
• No lubrication
• Visual on/off indication
• Compact design
• Longer life
• Corrosion resistant
• Low pressure drop
• Simplicity

Uses of ball valves:
The various uses of ball valves are as follows:

• They are used in situations where tight shut-off is required.
• They are wide duty pipe valves.
• They are able to transfer liquids with suspended solids (slurries), gases, liquids.
• They provide superior ease of operation.
• They can maintain and regulate high volume, high pressure and high temperature flow.
• The ball valve body design permits inspection as well as repair of seats and seals without removing the valves’ body from the line.
• Firesafe ball valves provide effective shut-off during or following a fire or when exposed to excessive temperatures.
• Ball valves are used in gas and oil pipelines.