Which type of pump is a positive displacement pump that can pump air?

Which type of pump is a positive displacement pump that can pump air?

• A. Priming pump
• B. Centrifugal pump
• C. Diaphragm pump
• D. Gear pump

Answer: (A)

A positive-displacement pump moves a fixed amount of fluid (or gas) with each cycle, so it can reliably move air as part of its operation. A priming pump is exactly the device used to remove air from the suction line and to prime the main pump, which means it must be capable of pumping air. That direct role of moving air to establish prime makes it the best fit for a pump described as a positive-displacement type that can pump air. Centrifugal pumps rely on dynamic pressure from spinning impellers and depend on a continuous liquid column, so they don’t prime well and aren’t designed to pump air effectively. A diaphragm pump is also a positive-displacement design and can pump air, but the question’s focus on a pump specifically used to move air to prime points to the priming pump as the intended answer. Gear pumps are positive-displacement and excellent for liquids, but are not typically used for priming with air.

A positive-displacement pump moves a fixed amount of fluid (or gas) with each cycle, so it can reliably move air as part of its operation. A priming pump is exactly the device used to remove air from the suction line and to prime the main pump, which means it must be capable of pumping air. That direct role of moving air to establish prime makes it the best fit for a pump described as a positive-displacement type that can pump air.

Centrifugal pumps rely on dynamic pressure from spinning impellers and depend on a continuous liquid column, so they don’t prime well and aren’t designed to pump air effectively. A diaphragm pump is also a positive-displacement design and can pump air, but the question’s focus on a pump specifically used to move air to prime points to the priming pump as the intended answer. Gear pumps are positive-displacement and excellent for liquids, but are not typically used for priming with air.