Expert brands in heat transfer fluid (HTF) like Paratherm stress the importance of testing. Regular analysis of thermal fluids in use is critical to ensure they are fit for purpose.
Testing can guarantee performance levels and extend the service life of the HTF, preventing damage, health and safety hazards, expensive repairs and operational downtime.
Without performing tests, operators can’t see the condition of the fluid, making analysis the only effective method of monitoring for unwanted issues like contaminants and thermal degradation, among others.
Here, we examine why testing is so important in detail, what thermal fluids should be tested for and how often tests should take place.
Why testing heat transfer fluids is necessary
Thermal fluid analysis detects degradation. Over time, HTFs break down when performing their role. This is especially the case when systems are operating at higher temperatures.
As they degrade, the sought after characteristics of the fluid are reduced, making it less effective. Regular testing is the best way to identify oxidative or thermal degradation.
Testing also lets operators monitor contamination levels. Contaminants like hydraulic fluid and water can result in component corrosion and reduced efficiency, but fluid analysis reveals when a range of contaminants are present.
Heat transfer fluids contain additives including corrosion inhibitors. Over time, these inclusions deplete and can increase the risk of damage to the heat transfer systems. Fluid tests assess levels and help system operators determine when they are too low.
Fluid analysis is also vital to ensure onsite safety. When HTFs break down, some of their decomposition products can become dangerous. Testing can calculate the risk of flammable deposits to mitigate health and safety issues.
Lastly, testing can prolong the active service life of thermal fluids. It identifies issues before they become bigger problems so that users can take corrective steps. Actions like cleaning filters and fluid dilution can extend the HTF’s effectiveness so that premature fluid replacement does not occur.
What to test heat transfer fluid for
When testing thermal fluids, there are key areas to examine. Check the HTF’s kinematic viscosity, which measures its resistance to flow. This impacts how efficiently it can transfer heat and its pumpability.
Find the fluid’s total acid number (TAN). This shows the level of acidity present in the HTF, which can indicate issues like corrosion and oxidation. Also identify the HTF’s flashpoint. This is the lowest temperature at which its vapours can ignite when exposed to a flame. The higher the flash point, the safer the fluid is to use.
Over time, natural processes can cause fluids to break down and decrease their effectiveness. Testing the HTF’s oxidation levels quantifies the extent of the degradation and helps determine if the fluid is still fit for service.
The fluid’s moisture content must also be checked. Other fluids like water and hydraulic fluid can contaminate the HTF, reducing the effectiveness of its properties. Not all contaminants are fluids however, so HTFs should be checked for insoluble solids that can’t be filtered out or broken down, which can cause scaling, fouling and a drop in performance.
How often to test heat transfer fluid
When you should test heat transfer fluids can depend on several factors including the age, size and type of system and when the thermal fluid was last changed.
When a new heat transfer system has been installed, experts advise the heat transfer fluid is tested within the first year of operation to identify any initial issues early. The scale of the system is also key; for example, a larger system should have its HTF checked at least once every year. If the system operates at high temperatures or close to its maximum limit for temperature, the thermal fluid will be more susceptible to degradation. As a result, the HTF should be analysed more frequently.
Finally, after thermal fluids are replaced, a test should always be performed to ensure it is operating at optimum and has not been contaminated by older fluid left in the system.
Do you require a fresh supply of heat transfer fluid?
Here at Oil Store, we supply a wide range of heat transfer fluids for different applications including food safe HTFs and products for both high and low temperature systems. For dependable thermal fluids from brands like Paratherm, Petronas, Mobil and Shell, reach out to our knowledgeable team of product experts.
