ARISE TECNICA
Ahmedabad, Gujarat
Industries: Railways
+91 81284 57080 · info@arisetecnica.com · Website
Listed manufacturers
What is a ball valve?
A ball with a bore sits between two seats in the body. When the bore lines up with the pipe the fluid flows through, and a quarter turn of the handle puts the solid side of the ball across the flow and shuts it off. Ball valves are made in brass, carbon steel, stainless steel and plastics, in full-bore or reduced-bore forms, with floating or trunnion-mounted balls for different pressures and sizes.
Ball Valve or gate valve?
A ball valve operates quickly, seals tightly and is compact, but it is not meant for fine throttling. A gate valve suits large lines where slow operation is acceptable, and is less expensive in big sizes.
What to specify when you ask for a quote
- Size, pressure class and end connection.
- Full-bore or reduced-bore, depending on how much flow resistance you can accept.
- Body, ball and seat materials, for example PTFE seats for many chemicals.
- Floating or trunnion-mounted ball for the pressure and size.
- Operation: lever, gear or actuator, and the fail-safe position needed.
- Design and test standard, fire-safe requirement if any, and certificates.
Where it is used
- Oil & GasShut-off in process and pipeline systems.
- Food ProcessingHygienic stainless valves in process lines.
- Water TreatmentIsolation of treated water and chemical dosing lines.
Frequently asked questions
What does full-bore mean?
A full-bore ball valve has a hole as large as the pipe, so flow resistance is very low and the line can be cleaned with a pig. A reduced-bore valve is smaller and cheaper but restricts flow a little.
Can a ball valve be used for throttling?
It can control flow roughly, but the seats can wear when the valve is held partly open. For accurate regulation, a globe or control valve is usually a better choice.
What is the difference between floating and trunnion ball valves?
In a floating design the ball is held by the seats and moves slightly under pressure to seal. A trunnion design has the ball supported by shafts, which carries higher loads and suits larger sizes and higher pressures.