Ball Valves

Ball Valves

Ball valves have a special feature allowing opening and closing with a 90° rotation. The ball valve is equipped with a cannulated ball and thus offers a great advantage compared to shut-off valves and gate valves.

In order to reduce the loss of flow in ball valves, the ball is precisely adapted to the body and has exactly the same diameter. Ball valves are available with reduced bore as well as with full bore. The ball valves listed here can be ordered by gear and handwheel, pneumatic or electric rotary actuator. Overall length according to ANSI B16.10. Any ball valve with a stem extension can be designed for underground installation.

Materials

The balls used in the housing are normally made of a wide variety of metals, while the seats are made of soft materials such as Teflon, neoprene or combinations of these materials.The use of soft seat materials provides ball valves with superior sealing properties. The disadvantage of soft seat materials (elastomers) is that they cannot be used in high temperature processes. For this purpose, metallic seals are used.For instance, fluorinated polymer seats can be utilized for operating temperatures from -200° (and higher) to 230°C and higher, whereas graphite seats can be used for temperatures from -° C to 500°C and higher.

The following lists a few typical applications of ball valves:

✓ Air, gas and liquid applications

✓ Drains and vents in liquid, gaseous and other liquid media

✓ Steam serviceAdvantages and disadvantages of ball valves

Advantages:

✓ Quick quarter turn on-off operation

✓ Tight-closing with low torque

✓ Smaller than most other valves

Disadvantages:

✓ Conventional ball valves have poor throttle characteristics

✓ In slurry or other applications, the suspended particles can settle and become trapped in body cavities resulting in wear, leakage or valve failure.