An electric motor driven by alternating electric current.

A dynamic compressor in which the gas is accelerated by the action of a bladed rotor and where the main flow is along the rotation axis of the rotor.

A dynamic compressor in which one ore more impellers accelerate the gas and where the main flow through the impeller is radial.

A dynamic pump that contains impellers provided with vanes to generate centrifugal force to achieve the required pressure head.

A physical object that is driven by a prime mover by which energy is either constantly or periodically added to an amount of gas in order to increase its pressure.

A physical object that adds or removes mechanical energy to a fluid, either constantly or periodically.

A positive displacement compressor in which forced reduction of gas volume takes place by the movement of a displacing element in a cylinder or enclosure.

A positive displacement pump which contains a displacing element intended to be moved in a reciprocating movement to exert pressure on a fluid, typically moving within a cylindrical space.

A positive displacement compressor in which compression displacement is effected by the positive action of rotating elements.

A positive displacement pump that consists of a chamber containing gears, cams, screws, vanes, plungers or similar elements actuated by relative rotation of the drive shaft or casing and which has no separate inlet and outlet valves.