Thermal fluids usually don’t telegraph that they are about to fail. Generally the only hint of impending doom is some fall off in temperature control in the heat user which requires an increase in the heater temperature to compensate. Once the power is shut off and the fluid cools however, it’s a very different story. If the fluid turns to molasses when it cools, it makes startup very difficult. Not to mention that pulling apart piping is a very time consuming way to replace the fluid.
If you operate a thermal fluid system, it’s easy to understand why thermal fluids fail. Unlike other central energy sources (like steam boilers) thermal fluid heaters don’t require (key word REQUIRE) any routine maintenance – no chemicals to add, no blowdown tanks, no condensate traps to mess with. Once you get beyond the initial startup the heater just runs.
This absence of required maintenance activities frees up operators for the 10,000 other items that do require attention. Which is why periodic sampling of the fluid should become a required maintenance activity. Even if the sample isn’t sent out for testing, simply examining the cooled fluid will give you a hint about the condition – i.e. if it doesn’t pour out of the sample container when you tip it over, you’re in trouble. (Here’s another hint: If this happens, don’t shut off the system. Give us a call.)
The next tip will review why where and how you sample is important.
See Paratherm’s one-minute video on fluid sampling and testing here —
Heat Transfer Fluid Sampling