Pumping units, pump assemblies and pumping methods

A pump assembly configured as a re-lift pump suitable for driving connection to a power unit to pump liquid to a discharge area, comprising:

• a vertically oriented pumping unit including:
• at least one impeller having:
• an impeller housing with an impeller housing intake end, an impeller housing outlet end and impeller housing interior extending from the impeller housing intake end to the impeller housing outlet end;
• and
• an impeller assembly in the impeller housing interior of the impeller housing and confined between the impeller housing intake end and the impeller housing outlet end, the impeller assembly including:
• an impeller hub;
• at least one impeller screw blade extending from the impeller hub, the at least one impeller screw blade having an impeller blade intake end disposed proximate the impeller housing intake end and an impeller blade outlet end disposed proximate the impeller housing outlet end of the impeller housing;
• and
• an impeller shaft drivingly engaging the impeller hub for rotation of the impeller assembly in the impeller housing interior, the impeller shaft configured for driving connection to the power unit;
• an intake cap carried by the impeller housing the impeller, the intake cap having:
• an intake cap housing including a cylindrical housing sidewall having a cap sidewall intake end and a cap sidewall outlet end, the housing sidewall continuous from the cap sidewall intake end to the cap sidewall outlet end, with an intake end plane of the cap sidewall intake end parallel to an outlet end plane of the cap sidewall outlet end, an intake cap housing flange protruding inwardly from the intake cap housing, an intake cap interior formed by the intake cap housing, an intake cap opening extending through the intake cap housing flange, a central shaft huh disposed in the intake cap interior and receiving the impeller shaft and a plurality of intake cap vanes extending inwardly from the intake cap housing into the intake cap interior to mount the shaft hub in the intake cap interior, the intake cap housing detachably coupled to the impeller housing intake end of the impeller housing of the impeller;
• and
• at least, one diffuser having:
• a diffuser housing with a diffuser housing intake end disposed in fluid communication with and detachably coupled to the impeller housing outlet end of the impeller housing, a diffuser housing outlet end and a diffuser housing interior extending from the diffuser housing intake end to the diffuser housing outlet end;
• a diffuser hub in the diffuser housing interior, the diffuser hub having a concentric outward taper from the diffuser housing intake end to the diffuser housing outlet end of the diffuser housing;
• a plurality of diffuser vanes extending from the diffuser hub in the diffuser housing interior of the diffuser housing;
• and
• at least one pump extension having a pump extension housing with a pump extension housing intake end disposed in fluid communication with and detachably coupled to the diffuser housing outlet end of the diffuser housing, a pump extension housing outlet end and a pump extension housing interior extending from the pump extension housing intake end to the pump extension housing outlet end;
• a re-lift cap including a re-lift cap housing disposed in fluid communication with the pump extension housing outlet end of the pump extension housing of the at least one pump extension;
• a horizontal drain conduit arm disposed in fluid communication with the re-lift cap housing;
• and
• whereby the intake cap is removable from the impeller as a first discrete unit, the impeller is removable from the diffuser as a second discrete unit and the diffuser is removable from the at least one pump extension as a third discrete unit.