Intercoolers and aftercoolers are used to remove the heat of the heat of compression from the process gas. An intercooler is used between compression stages to cool the gas before it enters the next stage. An aftercooler is used in a similar manner to remove the heat of the compression from the gas after it leaves the final compression discharge.

• The most commonly used intercoolers and aftercoolers are shell and tube type heat exchangers where the heat of the compression is transferred from the gas to a cooling medium circulated through the exchanger. The normal arrangement is to circulate the coolant through the tube side of the cooler and the gas around the tubes on the shell side.