Which statement about ball valves is correct?

Which statement about ball valves is correct?

• A. They cannot be used for throttling.
• B. They are only suitable for gas lines.
• C. They can be used to regulate or throttle flow.
• D. They are always cheaper than other valves.

Answer: (C)

Ball valves have a spherical flow path that, when turned, either aligns with or blocks the bore, giving a quick, reliable shutoff with low friction. They can also regulate or throttle flow if opened partially, though the flow versus position isn’t perfectly linear and continuous throttling can wear the seats over time. For precise control, other valve types like globe valves are preferred, but a ball valve is capable of both on-off operation and light throttling in many marine applications. The statements that they are only for gas lines or that they’re always cheaper are not accurate; their use and cost depend on the specific design, size, and materials.

Ball valves have a spherical flow path that, when turned, either aligns with or blocks the bore, giving a quick, reliable shutoff with low friction. They can also regulate or throttle flow if opened partially, though the flow versus position isn’t perfectly linear and continuous throttling can wear the seats over time. For precise control, other valve types like globe valves are preferred, but a ball valve is capable of both on-off operation and light throttling in many marine applications. The statements that they are only for gas lines or that they’re always cheaper are not accurate; their use and cost depend on the specific design, size, and materials.