Product image of our Below Ground Oil Water Separators.
Product image of our Below Ground Oil Water Separators.

Our below ground parallel corrugated plate oil water separators will remove essentially all free and dispersed non-emulsified oil droplets in the waste stream.


  • Removes free oil droplets as small as 20 microns
  • Reduces effluent free oil concentration factory tested prior to shipment
  • Performance guarantee based on influent characteristics
  • Warranted for (5) years on material and workmanship and (30) years against external and internal corrosion
  • Over 25,000 Plasteel tanks installed for petroleum storage since 1971 with no corrosion failures

Performance Standards

  • Design utilizes patented, revolutionary, non- plugging coalescing plates with 132 square feet per cubic foot of usable surface area that will remove a 20 micron droplet
  • Will not need to use secondary polishing packs
  • Will achieve discharge of 5ppm or less in accordance with CEN EN 858-1
  • Several companies meet UL2215 standards, but only a few of us meet CEN EN 858-1


Our design meets and exceeds API 421, which is based on Stokes Law. However, API does NOT address the importance of a Reynolds Number. Since Stokes Law is based on zero velocity, a low Reynolds Number is required to achieve the rise times of the oil for better separation.

With these separators, we can provide analysis, which indicates that, at the calculated overflow rate, the separator will be provided with the required square feet of projected plate separation area to achieve the specified performance under laminar flow (i.e. Reynolds Number of less than 500) conditions. Calculations shall take into account the rate of flow, potential surge flow, influent concentrations, particle characteristics, fluid temperature, fluid specific gravities, and pH. This service includes calculations signed by a registered professional engineer.

Construction Standards

  • Construction in accordance with UL58
  • Corrosion protection in accordance with UL1746, FRP, STi P3 or urethane
  • Single wall or double wall construction with interstitial space for leak detection
  • Meets NFPA 30 local requirements

Related Products