Essential Components of Pre-Engineered Thermal Fluid Systems

As closed-loop systems, pre-engineered thermal fluid systems provide a source of heat for various industrial processes. They achieve effective and efficient heat transfer through continuous fluid circulation. These alternatives to steam boilers offer optimal temperature control, reliability, and versatility, reaching high temperatures but operating at low pressures. They’re compatible with a wide range of industrial applications in a variety of industries.

Thermal fluid systems are made up of multiple important components, all working together to heat and cool products and maintain appropriate process temperatures. Learn more about these various components, and the parts they play in thermal fluid system operations.


One of the main components of a pre-engineered thermal fluid heating system is the heater, which raises the temperature of the thermal fluid per the needs of the application. System options include electric or gas-fired heaters. Electric heaters circulate process fluids around the system’s electric heating elements. They utilize electricity to raise the temperature of the thermal fluid rather than fuel oil, natural gas, or biomass fuel. Fired heaters are available in horizontal as well as vertical configurations, using flue gas to achieve the necessary temperature in the system’s coils and thus requiring minimal insulation. Both options come in an array of sizes and power capacities.


The heat load and size of the combustion chamber for your system will vary based on the thermal fluid system’s size and the type of process fluid it utilizes. Burners assist a system in handling the necessary power demands, heating thermal fluids prior to passing them throughout the system. When purchasing a pre-engineered thermal fluid system, your provider should be able to help you select the appropriate burner based on system size, the needs of your specific project, and other contributing factors.


Another component to consider is the system’s pump, which circulates the thermal fluid at a constant flow rate though the system. While the flow rate of the fluid through the heater is always constant, the flow rate can be varied through the heat consumers using flow control valves. The return temperature to the heater will vary depending on how much energy the heat consumers are using, and the burner will modulate to provide a constant supply temperature regardless of how the return temperature varies.

When selecting pumps for a thermal fluid system, the following considerations should factor into your decision:

  • Application: Pumps for thermal fluid systems are application-specific components. You can’t sub in standard hot water or boiler feed pumps for a thermal fluid system pump. Depending on your needs, you can choose from options like magnetically coupled pumps, water-cooled pumps, air-cooled pumps with mechanical seals, or API pumps, among others.
  • Material: Pumps are available in various material constructions to ensure they’ll be compatible with the necessary thermal fluids and operating conditions. For example, alloy steel is an optimal choice for positive displacement pumps, but types like centrifugal pumps typically include cast iron or ductile iron wetted components.
  • Pump Size: The size pump that you select must be compatible with the system. The right sizing will be dependent upon your system’s potential for pressure loss as well as the thermal fluid’s gravity when it’s at operational temperature.

Expansion and Drain Tanks


Thermal fluid systems must also use the right valves to operate. Valves must be resistant to leaking and wear at the high operating temperatures they will be exposed to Sigma Thermal recommends bellow-type seal for both manual and automated valves when operating at elevated temperatures. Bellows seal globe valves are more expensive that other types of high temperature valves, but they are also more effective and reliable for thermal oil, particularly at temperatures over 500F.

Control Panels

You also need the right control panel for your system to facilitate efficient operations. In conjunction with a system’s heater and all of it’s associated instrumentation, control panels enable you to continuously monitor all of the important system variables, safety functions, and control functions. This includes flow rate, thermal fluid temperatures, thermal fluid level, and exhaust gas temperatures for gas fired systems.

Simple and cost-effective control systems are available, as well as programmable logic controller (PLC) based systems that provide high-level functionality and communication with other plant systems.

Learn More About Thermal Fluid Systems

Specializing in industrial process heating solutions, Sigma Thermal handles thermal fluid system design, engineering, servicing, and training for customers worldwide. We offer electric and oil-fired systems in pre-engineered and custom-built options to best suit your needs. Our systems are simple yet robust, providing efficient, reliable temperature control. They’re easy to install and require minimal maintenance to deliver consistent and safe process heating with minimal downtime for your operation. Request a quote today to start your project.

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