Abstract
CUI (Corrosion Under Insulation) is among the key damage mechanisms affecting equipment and piping in hydrocarbon processing facilities, as well as pipelines. The key reason behind CUI is the contact of soaked insulations with the metal(s). Insulation stand-offs and membranes can keep the soaked insulation off the pipe and mitigate CUI risk. This research study addresses the CUI simulation tests to characterize the corrosion behaviors of carbon steel under isothermal wet and cyclic wet conditions, in the presence of insulation stand-offs, low point drains, and Teflon membranes. The corroded coupons were characterized using microscope and surface topography to investigate the damage modes namely pitting, uniform corrosion, localized damage. Insulation stand-offs with low point drains showed uniform corrosion in comparison to closed-contacting insulation, which mainly caused localized corrosion and pitting. Teflon membrane with low point drains caused the least corrosion rate among candidate configurations and did not show any noticeable surface damage from pitting or even uniform corrosion.
