Ningbo Leyan Machinery Technology Co., Ltd , https://www.cncleyan.com
Fire risk in thermal oil systems is extremely low due to the robust safety measures and protocols that have been refined over decades. Both manufacturers and users recognize the importance of proper design, operation, and maintenance to ensure the safety of personnel and equipment. At Pirobloc, we prioritize safety above all else, offering our customers highly efficient, reliable, and safe thermal fluid solutions.
### Causes of Fire in Industrial Hot Oil Heating Systems
Although fires in thermal fluid installations are rare, understanding potential causes is crucial for prevention. Here are the main reasons:
#### Leaks
Poorly designed or maintained systems can lead to leaks, often from faulty seals, gaskets, or hoses. When hot thermal fluid comes into contact with an ignition source, it can cause a fire. Common ignition sources include electrical panels, motors, and pumps located below the leak. Even small flange leaks can pose risks, which can be minimized by using high-quality graphite or Teflon gaskets.
#### Insulation Fires
These are very rare but occur when heat transfer fluid seeps into porous insulation materials like fiberglass or mineral wool. If the fluid is exposed to oxygen, it can self-ignite. To prevent this, closed-cell foam glass insulation should be used at leakage points, as it prevents fluid from spreading.
#### Undetected Loss of Flow
This occurs when a fault interrupts the flow of thermal oil. While rare, if combined with failed safety devices, it can lead to overheating and eventual rupture of piping. A tri-redundant SIL system, like those offered by Pirobloc, helps eliminate such risks.
#### Cracked Tubes
Though uncommon, cracked tubes made from unsuitable materials can lead to serious fires. Using ASME ASTM A106 Gr. B Sch. 40 piping is recommended. Cracks may form due to thermal cycling or internal soiling. If a crack occurs while the boiler is off, leaking fluid can accumulate in the combustion chamber, posing a major explosion risk.
### Assessing Fire Risk
Experts recommend evaluating three key parameters:
- **Flash point**: The temperature at which vapors ignite.
- **Ignition point**: Slightly higher than the flash point, indicating sustained burning.
- **Autoignition temperature**: The temperature at which a fire starts without an external source.
While these are important, most fires result from equipment failure rather than the fluid itself. Poor insulation, leaks, or loss of flow are more common causes.
### Fire Prevention Measures
To reduce fire risk, consider the following:
- Use closed-cell foam glass insulation (like FOAMGLAS®) around high-risk areas.
- Avoid porous insulation near potential leaks.
- Regularly inspect and maintain pump seals, valves, and flanges.
- Install low-flow shutdown systems on the burner safety interlock.
- Ensure adequate ventilation to prevent flammable vapors from accumulating.
- Keep drip pans clean and install containment berms to manage spills.
Proper design, regular maintenance, and adherence to safety guidelines are essential for long-term fire prevention.
### The Role of Thermal Insulation
Thermal insulation not only enhances energy efficiency but also plays a vital role in fire safety. Closed-cell insulation, such as FOAMGLAS®, prevents fluid from spreading and reduces the risk of auto-ignition. It also limits surface temperatures, protecting workers from burns.
In summary, while fire in thermal oil systems is highly unlikely, taking proactive steps—such as choosing the right materials, maintaining systems regularly, and following best practices—can further minimize any potential risks. At Pirobloc, we are committed to delivering safe, reliable, and high-performance thermal fluid solutions worldwide.
**Author: Carles Ferrer**
Carles Ferrer is an industrial engineer from Universitat de Barcelona and the Sales Director at Pirobloc. With extensive experience in thermal fluid projects across more than 80 countries, he brings valuable expertise to every project.
June 27, 2025