Grundfos End-suction pumps

Grundfos end-suction pumps are used in water supply, industrial pressure boosting, industrial liquid transfer, HVAC (heating, ventilation and air-conditioning), and irrigation.

The pumps are all non-self-priming single-stage, centrifugal volute pumps with axial suction port, radial discharge port and horizontal shaft. The Grundfos end-suction range comprises a complete series of close-coupled and long-coupled pumps in full compliance with EN733 and ISO2858.

The pumps are of the back pull-out design enabling removal of the motor, coupling, bearing bracket and impeller without disturbing the pump housing or pipework. Even the largest pumps can thus be serviced by a single person with a crane.

Please note that there are a number of specific product variants available for each model. Detailed information on these variants can be found in Grundfos Product Center.

ISO 2858 and EN733 specify the designations, nominal duty points and main dimensions of end-suction centrifugal pumps. Differences exist both within designation, nominal duty point and dimensions. Main differences are:

  • EN733 is a 10 bar std and ISO2858 is a 16 bar std.
  • The suction flange is in general bigger on the ISO pumps than on the EN pumps 
  • ISO 2858 has bigger shafts for the same powers in some occasions as for EN733
  • The built-in measures for ISO2858 is made so more space is prepared in the pump for special features as double seal, bigger bearings etc. (EN 733 is not)

The standards are only related to the norm pump, but many manufactures, including Grundfos, apply the standards to bloc pumps also. The standards only specify a certain range of end-suction pumps. There are 34 ISO models and 29 EN models. Pumps out side the ranges are referred to as under- and oversize pumps. Grundfos has 42 models.

NB/NBG Pumps
The NB/NBG is a close-coupled single–stage centrifugal pump with the motor and the pump part built together to a compact unit.
Standard: EN733 (NB) / ISO 2858 (NBG)
German sales name: Bloc
English sales name: Close-coupled

NK/NKG Pumps
The NK/NKG is a long-coupled single-stage centrifugal pump of a modular design comprising a motor, a coupling and a pump part, mounted on a base frame.
Standard: EN733 (NK) / ISO 2858 (NKG)
German sales name: Norm
English sales name: Long-coupled

Are pumps equipped with a motor with built-in frequency converter and the necessary application software to achieve an all-in-one solution enabling electronic speed control.
Electronic speed control enables continuously variable control of motor speed which again enables adaptation of the performance to a given requirement.