EVALUATION OF THE IMPACT OF OPERATING TEMPERATURE TO CORROSION RATE FOR (CUI)

CUI can be classified as severe form of localized corrosion that has been plaguing chemical process industries since the energy crisis of the 1970s forced plant designers to include much more insulation in their designs. Flow of water is the key problem in CUI. Moisture may be external or may be present in the insulation material itself. Corrosion may attack the jacketing, the insulation hardware, or the base of equipment. For high temperature equipment, water entering an insulation material and diffusing inward will eventually reach a region of dry out at the hot pipe or equipment wall. Then, to this dry out region is a zone in which the pores of the insulation are filled with a saturated salt solution. When a shutdown or process change occurs and the metal-wall temperature falls, the zone of saturated salt solution moves into the metal surface.