The purpose of the Veolia Water Technologies  STREAMLINER™ de-oiling hydrocyclone is to separate free oil from produced water prior to discharge or injection.


Usually situated after the primary separators, de-oiling hydrocyclones are normally regarded as the first stage in the treatment process. Long established as a process step, proven in service and having a compact footprint, they are one of the most commonly employed processes in a produced water treatment system. Energy to drive the process comes from the pressure in the separators.

How It Works

Produced water is injected under pressure into the larger diameter conical end of the hydrocyclone liner. The inlets are generally tangential to the wall of the liner so that the fluid entering the liner is made to rotate. Different inlet designs exist (depending on supplier) to induce this rotational vortex in the fluid. The conical shape of the hydrocyclone liner causes an increase in rotation speed as the diameter narrows, resulting in the development of high centrifugal forces and therefore the separation of the lighter oil from the heavier water and solids.

For more information on this process, see our STREAMLINER™ brochure.



The design of the new STREAMLINER™ range of de-oiling hydrocyclone incorporates unique features for improved reliability, performance and efficiency together with simplified operation and maintenance. Available as retrofits for existing installations or integrated into a complete produced water system, the STREAMLINER™ offers an unbeatable combination of performance, economy and whole life support from the water treatment expert in upstream oil & gas.

Benefits of the STREAMLINER design


  • Annular axial inlets reduce turbulence
  • Multiple inlets improve wear resistance
  • Swirl inducer can be inspected without liner disassembly
  • Retractable swirl inducer allows for internal liner inspection and easier jet cleaning
  • Liners can be retrofitted into existing installations
  • Geometry optimised for capacity and efficiency



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