Type series STU6

Power range up to approx. 80 m³/h and 650 m delivery head

STÜWA 6“ submersible pumps have been designed in the successful step-by-step way of construction: completely made of stainless steel with a wall thickness of 1.5 mm. Thus, we achieve an excellent resistance to abrasion by gritting materials such as sand etc. The built-in strainer prevents the infiltration of larger foreign bodies. Therefore, our pumps are ideally suited for production of drinking water. For the standard version, motors by FRANKLIN are used, also available by SUMOTO for instance.

With the standard engine speed of 2,900 RPM outstanding performance results are achieved. Power range up to approx. 80 m³/h and 650 m discharge head.

Available in 400 V, 3 phase 50 Hz from 0.55 kW up to 45 kW.

Areas of application

  • Drinking water production
  • Water supply in domestic homes and industry
  • Sprinkling and irrigation systems
  • Dewatering
  • Industry
  • Lowering of groundwater
  • Large waterworks
  • Field irrigation
  • Increase of pressure
  • Pumping of aggressive and chemical contaminated solids


  • Built-in check valve
  • Large power range
  • Solid and hard-wearing stainless-steel construction,
  • Stainless-steel material with a thickness of at least 1.5 mm.
  • High stability of the individual impellers due to generously dimensioned weld spots between the washer discs and the wings.
  • Generally equipped with 4 cable ties for high stability
  • Vertical or horizontal operation possible
  • Available in 400 V, 3 phase 50 Hz from 0.55 up to 45 kW, 2,900 RPM
  • Available in material quality type standard (1.4301), N (1.4401) and NE
  • Gasket seals of NBR or Viton (FKM)


Flow media:
Our submersible pumps of the STU6 type series are made for the conveyance of thin, clear, non-aggressive, aggressive and nonexplosive liquids without solids.

Aggressive solids, mat.: 1.4401 (AISI 316)

The pumps are suited for the conveyance of liquids with a sand content of up to 150 g/m³. A higher sand content shortens the operational life span of the pump.

The permissible temperature of the flow medium amounts to max. 30 °C.

Construction characteristics:

  • Coupling and motor flange of the pump part are prepared for the connection to a motor compliant to NEMA-Standard.
  • The check valve in the relieving chamber is constructed to ensure the smallest possible loss in the delivery head.
  • A generously dimensioned intermediate chamber is located at each pump level for a perfect balancing of the wave and for an optimisation of the lubrication.
  • Equipped with a sturdy cable protection bar
  • Hydraulic profiles to optimise high-performance rates
  • High resistance to corrosion and abrasion
  • Motor including temperature sensor

Conditions of characteristic curves:
Tolerances of characteristic curves compliant to ISO 9906:2012 Grade 3B

The characteristic curves state the pump performance using our standard motors with a standard rotational speed at 50 Hz.

The characteristic curves have been ascertained at a water temperature of 20 °C and in airless water, and remain valid at a viscosity of 1 mm²/sec.

Should liquids of a higher viscosity be pumped up, motors with adequately higher power must be employed.

The characteristics already allow for valve and inlet losses at standard rotational speed values of 50 Hz.

Power characteristic:
P2 shows the power requirements of the pump at the standard rotational speed of 50 Hz for each individual pump size.

Efficiency characteristic:
η efficiency of a single pump stage.

STÜWA STU6 submersible pump
STÜWA STU6 submersible pump
Check valve
Check valve
Check valve
Check valve
Intermediate chamber
Intermediate chamber
Shaft with coupling
Shaft with coupling