Indirect Line Heater

Indirect Line Heaters are used with high pressure natural gas streams to counteract the Joule-Thomson (JT) effect where a reduction in temperature occurs at the choke when the well stream pressure is rapidly reduced to sales line pressure. They can also be used to heat gas or oil in transmission lines.

Indirect Line Heaters help you maintain an optimal temperature in your well stream as pressures are rapidly reduced to sales line requirements. They counteract the effect of abrupt temperature drops that occur when the well stream passes through the pressure-reducing choke. They can also be used to heat gas transmission lines. Exterran Line Heaters can also be used for heating crude oil. Standard pre-assembled packages include coil, heater and fuel gas system and have rated capacities up to 4.0 MM BTU/hr. We can also customize a variety of coil arrangements and design pressures up to 15,000 psig, to help you achieve the most economical and efficient combination.

Key Benefits

  • Expedited production drawings available as early as 4-5 business days for faster planning
  • Single well or multi well designs available along with full pad well designs
  • Robust skid design and commitment to service help bring operations online quickly
  • Cost-effective maintenance
  • Installation and commissioning of the units to facilitate and speed startup
  • Industry-leading delivery to speed startup

How it Works

The Line Heater consists of three components: shell, firetube and coil. The process stream flows through the coil, which is immersed in the upper portion of the liquid media bath of the shell. The coil preheats the flow stream before reducing the pressure across a restricting choke followed by post-heating coils. Fuel gas is burned in the firetube and indirectly transfers heat to the media, then to the coil, and finally to the process stream.

Standard Features & Options

Standard Features

  • Heater shell with support saddles and lifting lugs
  • Removable U-bend type firetube
  • Removable firetube stack
  • Removable wellstream flow coil
  • High efficiency burner with pilot light and removable flame arrestor
  • ASME code-stamped, 250 psig fuel gas scrubber with internal high level safety shutdown valve
  • Fuel gas manifold with preheat coil and high and low pressure regulators
  • Pre-piped fuel gas manifold with preheat coil
  • Pressure gauge with isolating valve
  • Temperature controller with thermowell
  • Thermometer with thermowell
  • Shell fill connection
  • High quality enamel paint system


  • Down-draft diverter
  • Stack arrestor
  • High bath temperature shutdown
  • Energy conserving shop-installed fiberglass shell insulation with aluminum jacketing and vapor barrier
  • Dry leg fuel gas thief to source fuel for remote locations
  • Burner safety low (BSL)/igniter with optional solar panel
  • Pilot and diaphragm actuated choke valve
  • Special wellstream coils include multi-well and working pressures up to 15,000 psig
  • Inlet/outlet connections may be flanged, beveled for welding, or threaded
  • Heavy-duty oil-field type, I-beam skid
  • Containment skid
  • Expansion tank
  • Special paints and coatings
  • Sour gas service designed and built to NACE standards
  • Customization to meet additional specifications