The SwirlSep is a compact separator with high turndown capability. It is a combination of a control valve with special cage geometry, the SwirlValve™, and an inline separator, both complementary in their advantages.

The SwirlValve is similar to an axial or angular flow valve using a cage, however, having one distinct feature: the design of the trim cage is such that a swirling flow (a vortex) is created downstream of the valve by having tangential instead of radial holes. The major advantages of the swirling flow compared to the intense mixing and chaotic flow created by conventional valves are:

  • Smaller pressure drop over the valve
  • Minimum shear on the fluid
  • Reduced droplet/bubble break up
  • Coalescence of small droplets/ bubbles
  • Minimal Erosion
  • Because of the larger droplets the separation efficiency of the SwirlSep is proven to be very high.
Courtesy of Twister BV
Courtesy of Twister BV

The SwirlSep for the Oil & Gas industry is developed with and marketed through Frames Separation Technologies BV in Woerden, the Netherlands (www. Frames-Group.com).


The flow rate through the SwirlSep is regulated by controlling the position of the piston in the swirl trim cage. The centrifugal acceleration that results from the swirling motion is independent of the flow rate. The turndown range of the SwirlSep is therefore far larger (down to 10% of design flow) than for other inline separators, of which the turndown performance is limited due to the lack of swirling strength at low flow throughput.


As compact inline separator with a large turndown range, the SwirlSep technology is very flexible and is applicable for:

  • Demisting (liquids from gas/air)
  • Solids removal (dust, soot >8 microns from air)
  • Liquid degassing
  • Gas/liquid (bulk) separation
  • Liquid/liquid (bulk): (e.g. oil/ water)
  • Liquid/liquid (polishing, e.g. discharged water)
Courtesy  Frames Separation Technologies
Courtesy  Frames Separation Technologies