As professional engineer who develop industrial chiller, he must be familiar with the many aspect of the materials used into the chillers.
All of us know that one chiller cannot control every heat load. For example the low temperature chillers are designed to cool to very low temperatures while others are designed for only mid-range applications. Some designs can support very high flow rates of fluid while other may be designed for just a trickle of fluid. The same issues apply with ambient temperatures. Some chillers use refrigerant suited for a high ambient temperature environment while other refrigerants are formulated for cooler conditions.
Also, chiller engineers must know the difference between many kinds of coolant, such as R404A, R134a, R407c. And they must know which kind of coolant must be used for a specific chiller.
Engineers must also consider the fluid being cooled. Distilled water or di-ionized water requires different conditions than tap water. DI and distilled water can cause the breakdown of metal they come in contact with. In cases like this the chiller is designed with no brass, copper or mild steel components that would come in contact with the water, instead, plastic or stainless steel are used. This eliminates the corrosive effects of the fluid.