Which statement best describes the function of a bypass valve in a pipeline system?

Which statement best describes the function of a bypass valve in a pipeline system?

• A. It increases flow resistance in the main path.
• B. It vents gas to the atmosphere.
• C. It reduces differential pressure across a disk, making the main valve easier to operate.
• D. It acts as a check valve.

Answer: (C)

A bypass valve lowers the pressure difference across the main valve by providing an alternate flow path, which makes the main valve easier to operate. By letting some water pass around the main valve instead of through it, the upstream and downstream pressures become more balanced as the valve is opened or closed, reducing the torque or effort needed to move the valve disk. This is especially useful during valve operation or maintenance to prevent high loads on actuators and to keep service flowing downstream. It isn’t about venting gas, increasing resistance in the main path, or functioning as a check valve, so those options don’t fit as the best description.

A bypass valve lowers the pressure difference across the main valve by providing an alternate flow path, which makes the main valve easier to operate. By letting some water pass around the main valve instead of through it, the upstream and downstream pressures become more balanced as the valve is opened or closed, reducing the torque or effort needed to move the valve disk. This is especially useful during valve operation or maintenance to prevent high loads on actuators and to keep service flowing downstream. It isn’t about venting gas, increasing resistance in the main path, or functioning as a check valve, so those options don’t fit as the best description.