Type series STU4/STU4 (N) and STU4 (NE)

Power range up to approx. 8 m³/h and 360 m discharge head

STÜWA 4“ submersible pumps have been designed in the successful step-by-step way of construction: completely made of stainless steel with a wall thickness of 1.0 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 (series used with constant pressure).

With the standard engine speed of 2,900 RPM outstanding performance results are achieved. Power range up to approx. 8 m³/h and 360 m discharge head.

Available in two versions: 400 volt, 3 phase 50 Hz from 0.37 kW up to 7.5 kW

  • Drinking water production
  • Water supply in domestic homes and industry
  • Sprinkling and irrigation systems
  • Utilisation of rainwater
  • Industry
  • Production of raw materials
  • Lowering of groundwater
  • Dewatering
  • Heat pump systems
  • Built-in check valve
  • Large power range
  • Solid and hard-wearing stainless-steel construction, thus, excellent resistance to abrasion by sand and other abrasive materials
  • Stainless-steel material with a thickness of at least 1.0 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 Ph 50 Hz from 0.37 up to 7.5 KW, 2,900 RPM
  • Available in 230 V 50 Hz from 0.37 up to 1.1 KW with integrated starting condenser (2-wire)
  • Available in material quality type standard (1.4301), N (1.4401) and NE
  • Gasket seals of NBR or Viton (FKM)
  • Easy dismantling for cleaning purposes on site
  • Connection in Rp 1 ½“, as from size STU4. 7 connection available in Rp 2“
  • Equipped with eye for safety rope

Flow media:
Our submersible pumps of the STU4. or STU4. CP type series are made for the conveyance of thin, clear, non-aggressive and non-explosive liquids without solids.

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.

Installation conditions:
Our submersible pumps of the STU4. or STU4. CP type series can be installed horizontally or vertically. In order to ensure a sufficient cooling of the motor, the minimum inflow velocity of the flow medium must amount to at least 8 cm/sec at max. 30°C.

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 STU4 stainless-steel submersible pump
STÜWA STU4 stainless-steel submersible pump
Top bearing
Top bearing
Intermediate chamber
Intermediate chamber
Shaft with NEMA-coupling
Shaft with NEMA-coupling