CORROSION COMMENTARY

COOLING AND CORROSION. Sample of deposits from hot‐water space‐heating installations, water‐tube boilers and their condensate lines and from the cooling systems of internal combustion engines are received for analysis by the laboratory of the government chemist in London. These deposits most frequently consist of scale resulting from the use of a feed water of unsuitable composition, but occasionally the deposit consists of corrosion products arising from the materials of the boiler and its ancillary equipment. According to the latest ‘Report of the Government Chemist, 1958–59’, a recent case consisted of samples of the circulating cooling water and of scale from the oudet manifold of a diesel engine electricity generating plant at a War Department station abroad. Compared with the mains water used for make‐up, the cooling water in the engine had lost a considerable part of its hardness, the dissolved solids were higher and the chloride ion was 600 p.p.m.