Gravity oil water separators

AquaSweep™ Gravity Oil Water Separators are designed for gravity-induced separation of oil from water. This system is passive, meaning that the attributes of the incoming oily water will directly determine the characteristics of treated outgoing water. The separators are designed for gravity removal of non-emulsified hydrocarbons, i.e., motor oils, lightweight oils, and related petroleum products with a specific gravity of less than 1.0.

How does the AquaSweep™ Oil Water Separator Work?

Depending upon the AquaSweep™ model, the contaminated oily water follows a path through various pre-selected coalescer materials. The AquaSweep™ Gravity Oil Water Separator construction slows the flow and turbulence of the incoming water. The interplay of this motion, coupled with buoyant forces and contact with the coalescer material(s) cause droplets of oil to rise and combine into larger oil globules. The globules rise to the surface and float on top of the water. Sludge and other matter settle and accumulate at the bottom of the tank compartment. The resultant storm water, having been cleaned of these contaminants, exits the separator, below the oil level for further treatment or is directed back into the environment. Accumulation of oil and sludge within the separator are contained until they can be removed and disposed of properly.

AquaSweep™ Features

  • UL 2215 Listed and STI Engineered and Labeled
  • Available in a range of capacities, flow rates and effluent discharge efficiency levels rated as low as 5 ppm
  • Optional double-wall designs offer integral secondary containment
  • Level sensors and safeguard controls available
  • Corrosion protected tank built to nationally recognized STI standards with strict third-party quality control inspection program
  • Various coalescer materials are available that meet UL requirements

AquaSweep™ is available from an extensive group of Steel Tank Institute fabricators who participate in the STI Quality Control Program. Under the program, independent quality control inspectors make unannounced visits to STI members, ensuring fabrication to the highest possible standards.


  • AquaSweep
  • Tank Technologies
  • Underground