Indirect Fired Heaters

OTSO Indirect Fired Water, Salt and Steam Bath Heaters provide three methods for treating process streams without direct flame contact.  All three consist of a pressure vessel with a coil heating section that does not allow the process fluid to come into direct contact with the firetube.

Indirect Heaters are used in a multitude of oil and gas dehydration applications.  Water, Salt and Steam bath heaters all have distinct advantages based on the intended use.  OTSO can select and advise clients on which type of Indirect Fired Heater fits their application and offer a custom design heater to accommodate desired results.  

All our Indirect Heater packages function by liberating heat in a separate chamber.  This chamber heats the water, salt, and steam media thereby transferring heat to the process stream to induce drying.  The advantages of this process are reductions in scaling, plugging and coking due to an even transfer of heat throughout the system and lower interwall coil temperatures than direct fired heaters. 

Indirect heaters are a staple of the oil & gas industry and power generation sectors and are often used in various types of industrial applications.   

OTSO can design, size, engineer and fabricate custom Indirect Heaters to meet any application, regardless of size.

Common Indirect Heater Applications

Water Bath

  • High Pressure Wellhead Gas
  • Elimination Of Hydrate Formation In Gas Distribution Stations
  • Oilfield Production Heating High Pressure Oil or Gas
  • Heating Gas Pipelines for City Gate Stations
  • Reduced pumping pressure & boost efficiency via Viscosity

Salt Bath

  • Regeneration for Gas Service
  • Stabilization Service Via Liquid HydroCarbon Vaporization

Steam Bath

  • Temperature Maintenance for STorage of Heavy Hydrocarbons
  • Steam Generators (Low Pressure Operations)


Heater Features

  • Forced or Natural Draft Burners
  • Combination Burners for Oil & Gas
  • Gas Manifolds w/ Fuel Regulators
  • Firetube Liner Systems for Salt Bath Units
  • Stack Spark Arrestors
  • Flame Arrestors
  • Available w/ Fuel Gas Scrubbers


  • First-Out Annunciation Alarm Systems
  • Dual Temperature Control
  • Pilot Automatic Relight System
  • Pilot or Flame Detectors
  • Pilot Safety Shut-Downs
  • FM / FIA Control Systems

Process Coil

  • High Pressure Coil – 15,000 psig
  • Available in Carbon, Stainless and Specialized Alloys
  • Pressure Drop Designs Available


  • All Applicable Coatings Available
  • Standard w/ Aluminum Jacket Insulation
  • Comes Skid Mounted w/ Piping

A reliable Alternative Fuel Source

High Heating of Light Liquid Hydrocarbons

OTSO Indirect Heaters can provide a reliable alternative fuel source when designed to vaporize light hydrocarbon liquids. Incorporating Propane vaporizers provide industries and municipalities with a reliable primary, backup, standby of peak shaving fuel option in cases where natural gas is unavailable.

ASME Code and National Board stamped coils are used to heat the liquid process stream to an extreme high heat environment to vaporize the liquid.  The exiting vapor then becomes a fuel source.  OTSO vaporization packages range in size from small 250gpm systems to 10,000+gpm applications.  All systems are designed to meet industry standards for OSHA, Factory Mutual (FM) and Factory Insurance Association (FIA).