Common Misconception of Heat Transfer Fluid Flash Point
Source:Views:228Release time:2017-12-06

Common Misconception of Flash Point

In the process of technical support and after-sale service, technical engineers of Schultz ® heat transfer fluids find that many fluid users have the common misconception of fluid flash point. A lot of users think the higher flash point means higher temperature resistance. Instead of paying attention to fluid thermal stability, oxidation stability and thermal conductivity, many users only value the fluid flash point and make it to be the leading indicator for choosing the fluid.



Thermal stability is the most important indicator of heat transfer fluid. 

What’s the Flash Point?

Flash point is a safety indicator of heat transfer fluid during usage and storage. There are different requirements of flash point of different fluids based on the various usage modes. Unsafe factors occur when fluid flash point doesn’t meet the requirements. According to the Chinese heat transfer fluid regulation of GB23971-2009, the closed-cup flash point should not be below 100. But this regulation only sets the standard of open-cup flash point of L-QB fluids used in open-type system and has no standard of open-cup flash point in closed-type system. 

Flash points of synthetic heat transfer fluids sold on market are generally below 200. According to statistics, flash points of heat transfer fluids in common use in China are between 160200.


Operation temperature of heat transfer fluid is general above 250. The maximum operating temperature reaches 350 in fluid liquid phase and 400 in gas phase. Although system temperature is higher than fluid flash point, fluid is operated in a closed circulation system with no burning conditions (fuel, temperature and oxygen) and cannot be on fire, which has no influence on fluid furnace and system security. However, once system leaks, it’s easy to cause fire or explosion when high temperature fluid is exposed to flame or electrostatic spark even if the fluid flash point is very high. 

Flash point is not the leading indicator to measure fluid safety. Higher flash point doesn’t mean higher operation temperature. According to the Chinese heat transfer fluid regulations, heat transfer fluid does not belong to the flammable fluid category. The regulations demand that closed-cup flash point of heat transfer fluid should not be below 100.


Tips from Schultz Heat Transfer Fluid Experts

The leading indicator of fluid quality is thermal stability. Fluid thermal stability is the assessment index to evaluate fluid performance and safety. When choosing fluid, users should pay attention to fluid thermal stability and focus on thermal stability test conducted by national authorities. Please be out of the misunderstanding of fluid flash point.

Zhongneng Chemcial
Lianyungang, Jiangsu, China
Contact Us
Contact us or apply for product samples :
+86 518-83866808