FIRE EXTINGUISHERS CONTAINING INHIBITED LITHIUM CHLORIDE SOLUTION FOR POLAR USE

Previous experiments under this task using small metal test panels resulted in the selection of a sodium dichromate-oxalic acid inhibitor for use in protecting stainless steel from corrosion by a 24-percent lithium chloride solution. Subsequent testing with unlined stainless steel extinguishers showed that the inhibitor did not prevent intergranular and crevice corrosion. In this investigation, five different commercial extinguishers, fabricated of drawn brass or silicon bronze and lined with a lead alloys, were tested with the lithium chloride solution using either sodium dichromate-oxalic acid or sodium dichromate alone as an inhibitor. It was determined that 0.5 percent sodium dichromate satisfactorily inhibits corrosion by the water solution of lithium chloride when contained in an extinguisher of drawn brass.