This page is for indirect heating systems in food plants: fryers, dryers, cookers, extruders and thermal-oil heaters serving a production line. What an HT-1 heat transfer fluid is, how to choose by system temperature, the PARATHERM grades per TDS, and how to monitor the fluid. Send the operating temperature and the system volume; a Hop Tien engineer selects the fluid within 24 working hours.
A food-grade heat transfer fluid is one registered NSF HT-1: for indirect heating systems where the fluid could come into incidental contact with food through a leak. Choose by two temperatures: the bulk fluid temperature and the film temperature at the heating surface, both of which must stay below the limits in the TDS. PARATHERM NF (hydrotreated white oil, operation up to 332 °C, film 343 °C), PARATHERM HE (hydrotreated paraffinic, 332 °C, start-up from 3 °C) and PARATHERM CE (316 °C) are all registered NSF HT-1, Halal and Kosher. A system in steady operation needs periodic fluid analysis (viscosity, flash point, insolubles, low boilers); changing to a fluid of a different chemical family requires a complete drain.
| Fluid | Base | Viscosity at 40 °C | Max. operating | Max. film | Start-up | Registration |
|---|---|---|---|---|---|---|
| PARATHERM NF | Hydrotreated white oil | 20.5 mm²/s | 332 °C | 343 °C | −4 °C | NSF HT-1; Halal, Kosher |
| PARATHERM HE | Hydrotreated paraffinic | 41.5 mm²/s | 332 °C | 343 °C | 3 °C | NSF HT-1; Halal, Kosher |
| PARATHERM CE | Hydrotreated paraffinic | 29 mm²/s | 316 °C | — | 1 °C | NSF HT-1; Halal, Kosher |
Systems that do not require HT-1 (higher temperatures, chemicals, wood, plastics): see PARATHERM HT (up to 357 °C), HR (up to 357 °C, start-up from −13 °C), GLT (up to 302 °C); these grades are not HT-1 registered.
| System | Typical fluid temperature | Guidance |
|---|---|---|
| Continuous fryers, oil-heated ovens | 230–290 °C | A Hop Tien engineer advises the PARATHERM grade by film temperature and heater type (NF, HE: operation up to 332 °C, film 343 °C per TDS) |
| Drying, cooking, concentration, sterilization | 150–250 °C | PARATHERM CE or NF |
| Extrusion, calendering, heated packaging machines | 180–260 °C | PARATHERM NF, HE |
| Outdoor systems, cold start-up | Below 5 °C at start-up | PARATHERM NF (start-up from −4 °C per TDS); HE (3 °C) and CE (1 °C) need preheating before pumping |
Using another manufacturer's heat transfer fluid: what to check. Other H1 lubrication points in the plant: food-grade lubricants by lubrication point.
A heat transfer fluid registered HT-1 by NSF: for indirect heating systems where the fluid could come into incidental contact with food if it leaks. It differs from H1 (lubricants) in that HT-1 is assessed specifically for heat transfer fluids.
PARATHERM NF and HE operate up to 332 °C, with a film temperature of 343 °C; PARATHERM CE 316 °C (per TDS). The film temperature at the heating surface is the limit that decides.
A Hop Tien engineer advises the PARATHERM grade by film temperature and heater type. NF and HE operate up to 332 °C, film 343 °C per TDS; NF starts up from −4 °C, HE has a flash point above 210 °C (PMCC). Send the set temperature, heater type and system volume to decide.
By the results of periodic fluid analysis, usually every 6–12 months per the manufacturer's recommendation (viscosity, flash point, insolubles, low boilers), not on a fixed schedule; a system run within its temperature limits with a cool expansion tank can run for many years. A rapidly falling flash point is a sign of overheating.
Yes. Two different chemical families are not used together; the system must be drained completely, cleaned of carbon deposits if any, then filled with the new fluid by procedure; sample after a few hundred hours to confirm. A change within the hydrocarbon family only requires a complete drain and filtration.
Type of system (frying, drying, cooking), set fluid temperature and maximum temperature, heater type (fire tube, electric element), system volume, the fluid in use and the latest analysis results if available. The engineer replies within 24 working hours with the TDS.
Temperature, viscosity and registration data are given per the manufacturer's TDS published on each product page; the actual conditions of the system decide the final choice. Machine makes and trademarks named on this page belong to their respective manufacturers.
Each page has TDS data, registrations, pack sizes and a form to request documents.
IllustrationHeat transfer fluid based on high-purity hydrotreated mineral oil, NSF HT-1 registered (heat transfer fluid for incidental food…
IllustrationHeat transfer fluid based on highly refined hydrotreated paraffinic oil, NSF HT-1 registered (heat transfer fluid for incidental…
IllustrationHeat transfer fluid based on highly refined hydrotreated paraffinic oil, NSF HT-1 registered (heat transfer fluid for incidental…
IllustrationSynthetic heat transfer fluid based on partially hydrogenated terphenyl for closed-loop liquid-phase heating systems, bulk fluid…
IllustrationSynthetic alkyl aromatic heat transfer fluid for closed-loop liquid-phase heating systems, bulk fluid up to 357 °C and film up to…
IllustrationSynthetic alkyl aromatic heat transfer fluid for closed-loop liquid-phase heating systems up to 302 °C (direct-fired heaters 290…
