A method of cleaning equipment such as heat exchangers, evaporators, tanks andother industrial equipment using clean-in-place procedures and a pre-treatmentsolution prior to the conventional CIP cleaning process. The pre-treatmentstep improves the degree of softening of the soil, and thus facilitates itsremoval. The pre-treatment solution can be a strong acidic solution, a strongalkaline solution, or comprise a penetrant. A preferred strong acidic solutionis an acid peroxide solution. In some embodiments, the pre-treatment mayinclude no strong alkali or acid ingredient； rather, the penetrant providesacceptable levels of pre-treatment.
