What Is a Ball Valve?
A ball valve controls the flow of a fluid by means of a hollow, bored ball that rotates inside the valve body. When the bore of the ball is aligned with the pipeline, the valve is open and the medium passes through; when the handle or actuator turns the ball 90°, the bore is positioned across the flow and the passage is completely shut off.
Because it opens and closes with a simple quarter turn, the ball valve is one of the most widely used valves in industry. It is compact, easy to install, offers low pressure loss and provides reliable sealing even with frequent operation.
Working Principle
The ball is held between two seats and connected to a stem. Turning the stem by a quarter turn moves the ball between the fully open and fully closed positions. In the open position there is little or no narrowing of the flow section, so pressure loss is minimal. Ball valves are primarily designed for on/off service, and actuated versions allow remote or automatic operation.
Ball Valve Types
- Threaded ball valve: screwed to the pipeline; suited to small sizes and low-pressure lines. Three-way versions can direct flow at a pipe junction.
- Flanged ball valve: for heavy-duty lines, common in chemical, oil and gas systems.
- Mini ball valve: compact design for confined spaces, installations and irrigation systems.
- Floating ball valve: the ball is held by the seats; full-bore flow with near-zero pressure loss, widely used in LPG and petrochemical service.
- Top entry ball valve: allows internal access for maintenance without removing the valve from the line.
- API ball valve: high tightness under high pressure, used in machinery and oil transport lines.
- Hydraulic ball valve: for directing and controlling fluid in hydraulic systems under high pressure.
- Pneumatic and electric actuated ball valves: for automated on/off control in water, paper industry and gas distribution systems.
- Three-way ball valve: for diverting or mixing flows.
Materials
Ball valves are produced in steel, stainless steel, bronze, aluminium, plastic and other materials. Stainless steel is preferred for corrosive media, brass and bronze are common in water and low-temperature systems, and chrome-plated balls are an option where corrosion is not severe.
Technical Range
Luna Flow Control supplies ball valves from DN 8 to DN 300 (½″ – 24″), in pressure ratings from PN 10 – 63 and CL150 – CL2500 (150LB – 2500LB), for operating temperatures from -60 °C to +270 °C. End connections are flanged, socket-weld/butt-weld (SW/BW) or threaded, with lever, gearbox, electric, pneumatic or hydraulic actuation.
Application Areas
- Oil, gas and LPG systems
- Chemical and petrochemical plants
- Drinking water and municipal water networks
- Hot and cold water installations
- Paper industry and gas distribution
- Irrigation and general industrial piping
Advantages
- Fast, quarter-turn opening and closing
- Tight shut-off and low pressure loss
- Compact, space-saving design
- Suitable for frequent operation and long service life
- Easy to automate with actuators
Selection Tips
Choose the body material according to the medium, and confirm that the pressure rating and temperature range match the line's maximum operating conditions. Select the end connection to suit the pipeline, and consider an actuated version where frequent or remote operation is required.
