Tranter Platecoil is most often used to either heat or cool a manufacturing process liquid. When your process liquid needs to be cooled, Platecoil is most often immersed in a tank with a cooler liquid/gas circulating through the Platecoil. When looking to heat a process liquid, steam is often the heating agent. In some cases, the caustic nature of a liquid will require Platecoil made of stainless steel. In all cases, stainless will cost significantly more than carbon steel.
In one particular case an end-user tried to save money by using carbon steel material and coating it with a Teflon-like plastic. However, over time the coating gave way at a thin joint where the plates are welded, allowing fluid to enter. Before long, the carbon steel had completely dissolved into the process fluid and all that was left hanging from the Platecoil inlet and outlet piping was an expensive plastic baggie. Since material selection always rests with the end-user, please don’t get caught holding the bag.