Inspection of Petroleum Refinery Equipment

The conditions created by the presence of corrosive compounds in crude oils, the formation of corrosive compounds during processing and by the use of corrosive process chemicals makes constant inspection of refinery equipment necessary. The refinery equipment inspector must be familiar with construction and operation so he can anticipate and forestall expensive replacements. Corrosion caused by hydrogen sulfide formed during distillation by the breakdown of sulfur compounds usually can be predicted. However, the inspector always must be alert for localized overheating which will accelerate the corrosion rate. Naphthenic acids are most corrosive at their condensation points. Their presence in the crude oil or their formation during refining may cause severe localized corrosion wherever they are condensed or evaporated. Corrosion in gasoline storage tanks caused by moisture, oxygen and slight concentrations of other gases, proceeds at a low rate as compared to corrosion in distillation equipment. Nevertheless, it is responsible for major repairs.