Technical note: Electrochemical behaviour of metal inserts galvanically coupled to aluminium brass tubes

Abstract

Of the various methods presently in use to protect the inlet ends of copper alloy condenser tubes from impingement corrosion phenomena, that of positioning inserts at the tube inlets is widely favoured, although not entirely free from criticism. In fact, when plastic inserts are considered, corrosion can take place in the gaps that sometimes occur between the tube and the insert, while stainless steel inserts can give rise to localized corrosion just downstream of the inserts as a result of galvanic coupling between the stainless steel and the copper alloy.