Indirect Line Heaters Design & Sizing

An Overview of Oil & Gas Line Heaters

Also known as tankless heaters or indirect line heaters, oil and gas line heaters are widely used in different fields including the petrochemicals and energy industry for heating water, oil, and other hazardous chemicals.

Working Principle of Indirect Line Heaters

Line heaters work on the fundamental principle of heat flow, which states that heat transfers from a hot to a cold body and ensures equilibrium. Similar to conventional geysers, the heated medium flows out of the line heater system and is replaced continuously with cold fluid.

Line Heater Design & Sizing

A standard unit is designed to heat liquids and gases safely at various temperatures and pressures. It mainly consists of the following components:

  • Line Heaters Oil & GasCoil
    Coils are also known as a tube bundle. The fluid or gas that needs to be heated flows through one or more coils in the system. The coils are of two types, single pass and split pass. The typical arrangement consists of two coils in a line heater wherein one carries cold fluid into the system while the other coil rotates to maintain the desired temperature.
  • Coil Area
    This refers to the space where heat gets transferred and is calculated by considering the surface area of the pipe outside.
  • Choke
    The choke is a device used to check and control the rate of flow of the fluids in a line heater. As per the requirements and type, it may be located between the coils, on the coil outlet, or submerged in the bath.
  • Firetube
    A submerged chamber used to fire the heater. Typically, it consists of one or more U-shaped tubes that are flared at one end and connected to the heater bath.
  • Heater Bath
    It is an indirect heating medium used to heat water or other water-based solutions.
  • Sensors & Switches
    These are the major heating elements in the system used to ensure proper heating of the fluid or gas.

The size of the system depends on the following aspects:

  • The dimension of fire tubes.
  • The thickness of the pipe used in the equipment.
  • Diameter and length of the coils.
  • Whether or not any particular operating conditions are required.

The heat duty is determined according to the maximum volume of liquid or gas expected to flow into the system as well as the required temperature and pressure.

Industrial Applications of Line Heaters

Some of the uses are as follows:

  • Heating hazardous and corrosive fluids.
  • Oil and gas extraction.
  • Heating natural gas.
  • Manufacturing chemicals.
  • Various uses in the petrochemicals industry.

We Provide Complete Fabrication, Installation & Repair Services

At Aspire Energy Resources Inc., we have over 20 years experience and offer high-quality design and fabrication services. We ensure superior performance by using only high-quality equipment that meet the required industry standards. If you are looking to purchase indirect line heaters, you may reach out to our specialists by calling 403-314-5422 or 1-800-993-9958. We would be happy to discuss your project with you.

Request a Project Discussion: 403-314-5422 or

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