Dewatering Pumps

Vacuum-assisted wellpoint pump

A pump with a separate vacuum unit that holds prime on a suction line carrying air as well as water. Used on wellpoint and sump systems where the line is never fully flooded.

Features

  • A conventional self-priming pump loses prime when the suction line draws air; a vacuum-assisted unit keeps working on an air-water mixture, which is exactly what a wellpoint array produces.
  • The vacuum pump runs continuously or on demand, so it is a second machine to service and a second thing to fail.
  • Wellpoint systems are specified as a whole — spacing, header main size, and the pump — and the pump alone cannot be selected sensibly.
  • Continuous running for weeks or months is normal, so service intervals and consumable holdings matter more than purchase price.
  • Air handling capacity in m³/h is a separate specification from water flow and is what distinguishes these units.
  • Discharge water from a wellpoint system usually needs settlement before it goes anywhere, and that is part of the installation.

Specifications

Figure Typical range Unit Why it matters
Maximum water flow 60 - 300 m³/h Sizes the header main and outfall.
Air handling capacity 50 - 250 m³/h The figure that separates these from ordinary pumps.
Maximum vacuum −600 to −850 mbar Determines achievable drawdown depth.
Continuous duty rating 24 h These units run for weeks without stopping.
Suction / discharge size 100 / 150 / 200 mm Fixes the header main design.