Studies by the CISP, the Italian enamelling association, show that compared with alternative corrosion protection methods, like galvanizing, organic powder coating and duplex coatings, a porcelain enamel coating provides the longest lifetime expectancy for warm water tanks (see graph at bottom of page).

Initially boiler enamelling was exclusively done by means of various liquid application methods, which require large capital investments and a high level of process knowledge & skills on an operational level to obtain a good and consistent quality.

The introduction of electrostatic dry powder enamel application for the inside of hot water boilers simplifies the enameling process significantly and eliminates virtually all liquid, gaseous and/or solid waste emissions, resulting in a growing number of boiler enamelling plants with this technology worldwide.

According to the German standard the enamel layer should be at least 150 and should not exceed 500 microns.

The boilers should be manufactured from an enamellable steel grade and its design & welding methods used during manufacture should be in accordance to internationally recognised guide lines.