An electric motor driven by alternating electric current.

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

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

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 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.

A physical object that is a general term covering switching devices and their combination with associated control, measuring, protective and regulating equipment, also assemblies of such devices and equipment with associated interconnections, accessories, enclosures and supporting structures.