Elevated Flares

Variable Nozzle Sonic Flares (FlexMach Series)


  • Designed to achieve sonic exit velocity through the full range of flow
  • Spring actuated, adjustable orifice exit nozzles to maintain sonic velocity
  • Provides smokeless combustion through the full range of flow conditions
  • High pressure waste gas creates a turbulent mixing zone for greater combustion efficiency
  • Multi-arm design to maximize atmospheric air entry into the combustion zone

Selection Criteria / Advantages

  • Maintains sonic velocity throughout the entire flow range
  • Smokeless turndown from purge to 100% of design flow rate
  • Smokeless combustion with up to 25% by mass of entrained liquid hydrocarbons
  • Lower radiant heat than sub-sonic flares
  • Stable and reliable combustion
  • Lowest purge gas flow rate of any flare tip type
  • Upstream onshore oil & gas production
  • Upstream offshore oil & gas production
  • Midstream oil & gas
  • Petroleum refining
  • Chemical processing industry (CPI)
  • Nozzles designed to cross-light from a single point ignition source
  • Spring actuated exit nozzle
  • Fail open nozzle design in case of failure
  • Designed to accept a wide range of waste gas pressures
  • High temperature rated materials in the heat affected area
  • Variable exit nozzles act as velocity type purge seals to prevent flashback and minimize operating expense


Standard Length: 10’-0” [3048 mm]
Diameter: 4” – 84” [102 – 2134 mm]

Standard Materials:

Heat affected zone: stainless or high nickel alloy (as per application)
Non-heat affected zone: carbon steel

Book A Virtual Consultation