Freeze Protection for Impressed-Current, Cathodic-Protection Anodes in Water Storage Tanks

摘要

A technique was developed for supporting anode assemblies from the bottom of water storage tanks using polyester-type, fiberglass vertical columns. The columns were readily fabricated from the lightweight, non-metallic material; button-type anodes were easily positioned on the columns. The columns were supported in the tank by steel bases welded to the tank bottom. This was a unique departure from convention; impressed-current type anode assemblies are conventionally suspended from the roof of the tank using techniques which subject them to damage during the winter (i.e., icing conditions). It was established that the non-metallic, bottom-supported anode system was a viable approach for supporting anode assemblies in water-storage tanks. Where severe icing occurs, horizontal supports should not be connected between the columns and the tank wall. Equally important, it was found that header cables to the anodes and permanent reference electrode assemblies could be effectively protected from ice damage by encasing them in polyvinyl chloride conduit anchored to the tank surface. (Author)