Good to know when selecting the pump type

You have the choice!

Are you looking for a suitable combination of motor and pump? The large FLUX product range provides a unique selection of pump types and motors. Furthermore, there are numerous materials for pumps and O-rings as well as different impellers for the requested delivery rate. The following explanations and our FLUX experts will help you to make the right choice.

Mechanical seal or without seal

For standard applications, FLUX provides two high-quality pump types: pumps with mechanical seal or pumps without seal in the liquid area. Both pump types have an ingenious design.

Mechanical seal

  • Ideal for frequent medium changes, hardening media, fast drying media, crystallizing media
  • Can be taken apart into main components easily and quickly for cleaning
  • Higher service life on abrasive media compared to sealless pumps
  • High stability plastic pumps enable immersion lengths of up to 3.000 mm
  • Versions in stainless steel and Hastelloy C can be used in hazardous areas*
  • FOOD version conforms EC 1935/2004 and FDA CFR 21 for contact with food
Diagram of a FLUX pump with mechanical seal

* according to EC Directive 2014/34/EU


  • No seal wear
  • Optimal emptying of the inner tube
  • High service life
  • Low wear of guide bearing and shaft
  • Long bearing life
  • Particularly suited for hydrochloric acid and chromic acid
  • Stainless steel version for use in hazardous areas*
  • Versions for use with AdBlue® also available
Diagram of a sealless drum pump

Impellers for the requested delivery rate

Comparison of the characteristic curve of a drum pump F/FP 430 with motor F 457 with axial impeller 38 mm and semi-axial impeller (Z-version) 37 mm
  • FLUX offers two different types of impellers.
  • The geometry of the axial impeller provides for small flow losses in circumferential direction, flow is almost completely axial. Used when high flow rates are required at low pressure requirements.
  • The geometry of the semi-axial impellers (Z-version) provides mainly for a flow in circumferential direction. Combined with the pressure ring, the flow is redirected in axial direction. This provides a higher delivery pressure at a lower delivery rate. Semi-axial impellers are used in case of an increased pressure requirement.
  • All impellers are in ethylene-tetrafluoroethylene (ETFE).
  • Axial impeller with diameter 38 mm is also available in stainless steel.
F/FP 430 with mechanical seal and axial impeller
F/FP 430 with mechanical seal and axial impeller

Use of axial impellers

  • For high delivery rates
  • For light media (density up to1.3 kg/dm³)
  • For short discharge lines
  • For small differences in height
  • For low pressure losses
F/FP 430 with mechanical seal and semi-axial impeller (Z-version)
F/FP 430 with mechanical seal and semi-axial impeller (Z-version)

Use of semi-axial impellers (Z-version)

  • For high delivery heads
  • For heavy media (density from 1.3 kg/dm³)
  • For long discharge lines
  • For big differences in height
  • For pressure losses due to valves and fittings

Outer diameter of different series 400 pump types and impeller diameter resp. geometries

Materials of different series 400 pump types and standard combination with O-ring materials

Overview of series 400 pump types:
Quick and easy to select the right pump for your requirement