This European Standard specifies the minimum requirements and the functional characteristics of enamel coatings applied by any enamel process, such as: wet dipping, wet flow-coating, wet spraying, wet electrostatic spraying, wet electro deposition or dry powder electrostatic spraying, to profiled steel heat exchanger panels in regenerative heat exchangers, before and after packing in baskets. NOTE For very severe service conditions, or to obtain extended operation life, more stringent limits may be agreed between customer and supplier.