Effect of Inorganic Contaminants on the Corrosion of Metals in Chlorinated Solvents^*

In tests on unstabilized chlorinated solvents, corrosion rates for common materials of construction were high in the condensing area when both dissolved water and HCl, a degradation product, exceeded critical low concentrations. In tests where corrosion in the condensate was severe, corrosion rates in the boiling solution were very low because concentrations of dissolved water were below a critical low value. For low rates in both solution and condensing areas, HCl and water content should be kept below 40 and 200 ppm, respectively. Use of stabilizers and selection of materials to minimize corrosion are described also.