Paratherm heat transfer fluids are a globally-trusted product range used in industrial processes. They offer the ability to deliver high-temperature heating at low system pressures.
These fluids – including petroleum-based, synthetic hydrocarbons or siloxanes – offer excellent thermal stability and safety while reducing maintenance needs.
In order for Paratherm heat transfer fluids to support performance and extend system life, there are a few critical precautions and measures for upkeep.
This article discusses 10 essential maintenance tips for Paratherm heat transfer systems.
Never mix heat transfer fluids
Mixing different fluids, especially those with varying hydrocarbon structures, can lead to unpredictable chemical interactions under high temperatures and turbulence.
With system contaminants acting as catalysts, the result may be corrosive or sludge-forming compounds. To avoid equipment damage and compromised performance, never mix heat transfer fluids. Always use the appropriate Paratherm product specified for your system.
Thoroughly clean new systems
New systems may contain both hard and soft contaminants. Weld slag, mill scale and metal spatter can severely damage seals, pump bearings and control valves.
Coatings like protective lacquers or residual oils are thermally unstable and can trigger premature fluid degradation.
Before introducing heat transfer fluid, ensure all pipes, components and fittings are thoroughly cleaned and dried. This will help to prevent future operational problems.
Ensure complete water removal
Water is a huge concern in heat transfer systems. Even a small amount of moisture can cause cavitation and corrosion. In worst-case scenarios, pipe rupture can occur due to flash steam.
Locate low points in the system and drain small fluid samples into a beaker. If there is water separation, keep draining and jog the pump to circulate new fluid until the water is fully expelled. Finish by running the system at around 225°F with all vents open to safely steam off residual moisture. Avoid hydro-testing with water; opt for inert gas or the fluid itself.
Leak testing and prevention
Heat transfer fluids can escape through gaskets, seals or fittings that have been improperly installed. This is especially true under thermal expansion.
Perform leak tests by pressurising the system with inert gas and applying soap solution to suspected areas. Preventing leaks protects both personnel and the fluid itself from exposure and contamination.
Drain and observe before maintenance
When draining the system, first heat the fluid to around 225°F to reduce viscosity and keep contaminants suspended. Then, thoroughly drain from all system low points.
Watch for signs of carbon chunks or solids. If visible, it’s a signal that the system may need flushing with clean heat transfer fluid before refilling.
Charge from the bottom
The system should always be charged from a low point; ideally near the pump suction, such as the blowdown valve on the strainer.
This “bottom-filling” method helps displace air naturally, minimising the risk of cavitation. Consider purging the system with inert gas beforehand to remove oxygen and assist in drying any vapour.
Prevent oxidation with inert gas blanketing
Organic heat transfer fluids are vulnerable to oxidation when exposed to air, even at temperatures as low as 250°F. Oxidation thickens the fluid, increases acidity and leads to sludge and deposit formation.
If the expansion tank reaches over 200°F, install an inert gas (such as nitrogen) blanket to protect the fluid from air exposure. Systems with deaerator or cold-seal tanks should have the deaerator portion insulated, with the remainder exposed to allow for proper thermal regulation.
Prepare for cold weather deliveries
Fluids shipped in cold conditions may contain entrained air. This can cause cavitation if pumped directly into the system.
Paratherm heat transfer fluid should always be brought close to room temperature before charging. Store drums indoors or use drum warmers to reduce viscosity and eliminate trapped gases. When a fluid is warm, it flows better and enters the system more safely and effectively.
Prioritise cleanliness during installation
Contaminants introduced during installation can significantly shorten fluid and equipment life.
Any mill scale, welding debris, lacquer and oils should be removed from every section of piping and all components before the system is put into service. Clean and dry the heater and any fluid users so contaminants don’t cause degradation once heat is applied.
Regular fluid analysis
Routine testing is important to identify problems before they escalate. Check and clean all filters and strainers before start-up, and inspect them again shortly afterwards to catch residual contaminants.
Conduct fluid analysis regularly to monitor oxidation levels, thermal degradation and contamination.
Using these system care tips can help to get the most from Paratherm heat transfer fluids, increase productivity and protect your investments.
