Problem Solving Forum
January 31 - February 6, 2016
Under what types of exterior atmospheric exposures (other than marine) is it necessary to test for soluble salts?
Stephen Bothello of Jotun UAE Ltd on
February 4, 2016:
Exterior Atmospheric exposures defined by ISO 1294 ...read more Exterior Atmospheric exposures defined by ISO 12944, Corrosivity Category C3, C4 and C5 Industrial. This is basically locations where corrosion rates range from medium to high, caused by increased rate of air pollution and the daily wet (humidity/ condensation) and dry cycles, like, for example, gas transmission pipelines and above ground water storage tanks. Specifically, when durability of 15 years or more is desired, salt tests are essential, though the frequency may be less than on steel intended for marine environments. It is to be noted that a lot of steel not intended for exposure in marine environments is, however, exposed to marine environments, due to transportation by sea from distant countries, many times unprotected. Steel stored at project or yard lay-down sites or open areas may also get exposed to high salt levels from dust or industrial emissions. Salt contamination from abrasives used for blasting is an added factor.
Jim Johnson of CHLOR*RID International Inc. on
February 1, 2016:
The most commonly encountered soluble salts, chlor ...read more The most commonly encountered soluble salts, chloride, sulfate and nitrate, are found all across the country. They come not only from marine environments, but also from burning fossil fuels and using industrial chemicals. Maps available from the National Atmospheric Deposition Program show that salt contamination occurs everywhere in the US. In every case I have seen, in over 25 years that I've worked in this industry, testing is ALWAYS less costly than a premature failure.