Liquid Seal Drum


  • Designed to prevent flashback by creating a water barrier between the flare and the waste gas source
  • Waste gas flows into the liquid seal and down through a submersed conical exit baffle
  • Designed to bubble the waste gas through the water to ensure there is no path for a flashback to penetrate the water barrier
  • Often used to stage or control flow rates to multiple relief devices

Selection Criteria / Advantages

  • Prevents flashback of gas types a through d
  • Creates positive pressure in the flare header
  • Will collect entrained liquids before reaching flare tip
  • Multiple units can be utilized for staging purposes
  • Automatic water level control system available
  • Can be combined with a knockout drum in a single vessel
  • Proprietary diffuser and baffle system minimize water surging
  • Includes a skimmer to remove hydrocarbon liquid droplets
  • No moving parts
  • Can be designed and stamped as an ASME Section VIII pressure vessel


Standard height / length: 5’ – 50’ + [1.5 m – 15.2 m +]
Diameter: 24” – 144” + [610 – 3658 mm +]

Standard Materials:

Internals: stainless and carbon steel
Vessel: carbon steel

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