Paratherm GLT HTF is a synthetic, aromatic heat transfer fluid that has been engineered to deliver excellent cost performance and pumpability compared to conventional mineral oil heat transfer fluids. It can be used in low-temperature start-up systems and offers high efficiency and thermal stability. Paratherm GLT provides outstanding performance up to 554°F (290°C) in closed-loop liquid phase heating systems and is chemically equivalent and compatible with Therminol 55.
When compared to its closest competitive product, Paratherm GLT heat transfer fluid exhibits nearly 40% less degradation when held continuously at 650°F for 500hrs (Thermal Stability – ASTM D6743). This level of stability helps ensure that even when pushed to its limits, Paratherm GLT is engineered to perform.
Minimum start-up temperature is a realistic measure of a fluid’s low temperature capability since 300cPs is typically considered the maximum viscosity standard centrifugal pumps will handle. Paratherm GLT has a lower minimum start-up temperature than any mineral-oil based fluid that cover a similar temperature range making it advantageously suited for cold climate applications.
Operating Range for Paratherm GLT HTF
Minimum Startup Temperature (300cSt)
Maximum Operating Temperature
12°F / -11°C
575°F / 302°C
Resources & Documents
View the technical data information for Paratherm GLT Heat Transfer Fluid
View the Material Safety Data Sheet for Paratherm GLT Heat Transfer Fluid
Extending Fluid Lifetime
When Paratherm fluids are used as recommended they can provide many years of reliable service. Systems using Paratherm fluids should be designed and installed by qualified engineers and should be maintained as any other critical production asset. Fluid oxidation is the leading cause of the most serious maintenance issues associated with closed-loop heat transfer systems– including cold spots, heater coking, plugged pressure sensors and ultimately fluid gelling. Paratherm recommends installation of a nitrogen blanket on the expansion tank to prevent oxidation of the fluid. All systems may benefit from side-stream filtration to promote long-term fluid and system reliability.Fluid Analysis Services
Paratherm offers a comprehensive fluid monitoring service to help keep systems running at their best. Their state-of-the-art laboratory is certified to ISO 9001:2015 and well-equipped to run all critical tests. Annual testing is recommended and can identify system issues before they become catastrophic. The fluid in new systems should be tested within 9 to 12 months of start-up. New fluid in existing systems should be tested within the first month of operation to establish a base line for future testing, and annually thereafter.Replacing Fluid
Replacement should be preceded by analysis of the fluid to determine if cleaning or flushing of the system is recommended prior to introducing new heat transfer fluid. Newly commissioned systems typically do not require cleaning before filling. Paratherm recommends installation of a Y-strainer with a minimum 60-mesh screen up-stream of the pump to catch any residues from manufacturing and construction of system components.Fluid Storage
Barrels and pails should be stored indoors to prevent environmental contamination. If sealed barrels must be left outdoors, provisions should be made to prevent water from pooling on their tops. While unopened pails are considered weatherproof, Paratherm recommends they not be stacked when stored outdoors. If the fluid is below its minimum pumpable temperature, the containers may be moved indoors to warm up before charging into the system. Refer to the product safety data sheet (SDS) for additional handling and storage recommendations.
Speak to us
If you have a big system requirement, Paratherm can fill high-volume systems from bulk tanker. Get in touch with the Oil-Store team to request a bulk quotation.