Fluid Life Tests While oxidation is the #1 reason that heat transfer fluids need to be replaced, it doesn’t always follow that using a fluid with an oxidation inhibitor will prevent oxidative sludging. Oxidation inhibitors are chemical additives designed to prevent the sludge formation, acidification, and viscosity increases that result when air and hot […]
Does lab testing tell the whole story? There are a number of accelerated aging laboratory tests that are designed to determine oxidation-inhibitor performance and longevity. Most involve bubbling pure oxygen through a heated sample that has an oxidation catalyst (usually copper wire) submerged in it. The effectiveness of the additive is determined by measuring the […]
When designing or maintaining a hot-oil system, one important aspect is thermal insulation; adequate insulation is a necessary evil on these systems. Even if energy costs were zero, there would still be the need to protect company personnel (especially overzealous young process engineers and nosy visitors from headquarters) from exposure to hot pipes. Not to […]
Minimizing fire hazard from insulation is very straightforward — if you have the money. Insulation is nothing more than a large number of air pockets that are held in place by some type of material. For high temperature systems, these materials may consist of mineral fibers, compressed particles (calcium silicate or perlite) or cellular glass […]
Reduce Insulation Fire Potential While Controlling Cost Although it almost eliminates the potential for insulation fires, good quality cellular glass insulation (like FOAMGLAS) is significantly more expensive both to purchase and install than the mineral fiber (fiber glass or glass wool) or compressed particle (calcium silicate or perlite) type materials. The trick to “optimizing” insulation […]
Where and how you take a thermal fluid sample can make all the difference in what the test results reveal. Where a sample should be taken is simple – any location where there is flow and the temperature is above 180°F. A blowdown valve on the pump suction strainer housing is a good bet since […]
Why Sample? 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 […]
How well (or how poorly) does lab testing reflect real-world manufacturing conditions? In the real world, oxidation of heat transfer fluids occurs in a vented reservoir or expansion tank that for whatever reason is hot (>70°C). The acids formed in the expansion tank subsequently circulate through the system, decomposing in the heater and producing […]
