Knock Out Drum


When ever a process requires that entrained droplets be removed From a vapor stream, Flare Industries includes a knockout drum in the system design. Condensation can occur when hot process gases cool considerably in the flare gas header and riser, and some gases also go to dew point at ambient temperatures and pressures and can therefore generate liquids. These droplets must be removed in order to avoid the phenomenon known as flaming rain, which occurs when liquid droplets are blown out the top of a flare stack along with ignited process gases. In order to avoid this hazard, Flare Industries provides the knockout drum. Designed to remove particles as small as 50 microns in size. The vessel can be outfitted with a wide variety of instrumentation. Flare Industries provides both horizontal and vertical configurations.


Diameter: 24” to 180”
Height: 5’ to 50’
Wall Thickness: Varies
Materials: Carbon steel, stainless steel, others
Code design: ASME or By customer request
Style: Cyclonic or traditional
Orientation: Vertical or horizontal
System integration: Stand alone or integral to stack


  • Gases that go to dew point at ambient pressures and temperatures Hot gases .
  • Heavy hydrocarbons with a tendency to condense .
  • Terminal loading facilities Refineries.
  • Petrochemical facilities .