Wilo-Sub TWI 6

Series description

Your advantages

  • Long service life thanks to corrosion-resistant stainless steel, optionally available in V4A quality
  • Individually configurable motors and materials to ensure reliable operation in all applications
  • Drinking water versions with ACS approval
  • 4", 6", 8" and 10" versions for high flexibility
  • Volume flow performance from 1 to 250 m³/h


Multistage 6" submersible pump in tie strap version for vertical or horizontal installation


  • For water and drinking water supply from boreholes and rainwater storage
  • Process water supply
  • For municipal water supply, sprinkling and irrigation
  • Pressure boosting
  • Lowering of the water level
  • For pumping water in industrial applications
  • For pumping water without long-fibre and abrasive constituents


  • Multistage submersible pump with radial or semi-axial impellers
  • Integrated non-return valve
  • NEMA coupling
  • Three-phase current motor
  • Hermetically sealed motors
  • Rewindable motors

Scope of delivery

  • Hydraulics and motor ready assembled
  • 4/5/10 m connection cable approved for drinking water (cross-section: 4x2.5 mm2 or 4x4 mm2)
  • Installation and operating instructions

Type key


Wilo-Sub TWI 6.18-04-C-SD


Submersible pump


Diameter of the hydraulic unit in inches ["]


Rated volume flow [m3/h]


Number of hydraulic stages


Series generation


Motor shroud in 1.4571, motor connection via flat male tab


Starting mode Without = direct starting SD = star-delta starting

Technical data

  • Mains connection: 3~400 V, 50 Hz
  • Submerged operating mode: S1
  • Fluid temperature: 3 – 30 °C
  • Minimum flow rate at motor:
    • Hermetically cast motors: 0.08 - 0.16 m/s
    • Rewindable motors (SD-R): 0.1 - 0.5 m/s (depending on type)
  • Max. sand content: 50 g/m3
  • Max. number of starts: 20/h
  • Max. immersion depth:
    • Hermetically cast motors: 350 m
    • Rewindable motors: 100 m
  • Protection class: IP68
  • Pressure connection: Rp 2½ - Rp 3


  • Hydraulics housing: Stainless steel 1.4301
  • Impellers: Stainless steel 1.4301
  • Hydraulic shaft: Stainless steel 1.4057
  • Motor housing: EN-GJL or stainless steel 1.4301
  • Motor shaft: Stainless steel 1.4305 or 1.4301


Submersible pump with ACS approval for vertical or horizontal installation.


Multistage submersible-motor pump with 4" or 6" NEMA connection and radial or semi-axial impellers with sectional construction. Integrated non-return valve. All parts that come in contact with the fluid are made of corrosion-free materials.


Three-phase motor for direct and star-delta start. Sealed, hermetically cast motor with enamel-insulated winding, resin-impregnated, or rewindable motor with PVC-insulated winding, self-lubricating bearing, with water-glycol filling.


The motor is cooled by the pumped fluid. The motor must always be immersed when operated. The limit values for maximum fluid temperature and minimum flow velocity must be adhered to. Vertical installation is possible with or without cooling jacket. Horizontal installation must be performed in conjunction with a cooling jacket.

Pressure shroud

The pressure shroud is used for the direct installation of the unit in the pipe system. Standard models are without mounted non-return valves. The maximum inlet pressure is 10 bar.

Duty chart

Sub TWI 6


REACH regulation

Edition 2020-08
Page format 209.9 x 296.7 mm
Number of pages 4

PDF (1 MB)


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Article Number 6080455
Edition 2020-08
Version number 05
Page format 209.9 x 297.0 mm
Number of pages 68

PDF (5 MB)


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General overview 2020 International version

Edition 2020
Version number 1
Page format 209.9 x 297.0 mm
Number of pages 78

PDF (48 MB)


Wilo-Sub TWI 4-6

Article Number 4069717
Edition 0801
Version number 03
Page format A4
Number of pages 15

PDF (913 kB)


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Article Number 4069717
Edition 0801
Version number 03
Page format A4
Number of pages 60

PDF (3 MB)



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