Glossary

Dynamic pump that moves liquids by using a spinning impeller housed in a volute (pump casing).

Rotary positive displacement pump that uses two rotors mounted on separate shafts. Also called an external circumferential piston pump.

Rotary positive displacement pump that uses two identical external gears arranged side-by-side.

Rotary positive-displacement pump that uses the motion of interlocking gears to move fluid.

Internal gear pump in which the pump action is created by two gears, but without a crescent-shaped partition.

Rotary positive displacement pump that moves liquid by using two gears in a “gear‑within‑a‑gear” arrangement.

Positive displacement pump that uses pairs of externally timed, non‑contacting lobed rotors to move fluid through the pump housing with each rotation.

Rotary positive displacement pump that moves liquid using a spinning rotor with multiple sliding vanes inside a contoured (cam‑shaped) housing.

Air‑operated double diaphragm (AODD) pump is a positive displacement pump that uses compressed air to alternately actuate a pair of flexible diaphragms.