Heat exchangers are unfired heat transfer equipment used in process plants. Heat exchangers are used for the transfer of heat or cold between two fluids for the purpose of heating the process, cooling the process, or condensing vapors during the process.

The marine heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. Shell and tube heat exchangers consist of a series of tubes. One set of these tubes contains the fluid that must be either heated or cooled. The second fluid runs over the tubes that are being heated or cooled so that it can either provide the heat or absorb the heat.