CUI Management Through Moisture Barrier System and Field Assessment

authors: Ahmad Raza Khan Rana, Graham Brigham, Andrew Buchanan

This article presents a case study of moisture management where a hydrocarbon operator faced the challenge of frequent soaking of thermal insulation that caused the operator to replace the entire insulation on a multi-kilometer pipeline twice within an operating period of 10 years. The newer insulation was installed with and without various combinations of moisture barrier devices. Assessments were made on a bi-weekly basis over a period of 7 months. The various combinations of moisture barrier devices significantly reduced the moisture content of the entire insulation system. This article also addresses the modular management via termination gaskets for the compartmentalization and assessment of trapped moisture within any insulation system. Read more...

Influence of Robust Drain Openings and Insulation Standoffs on Corrosion Under Insulation Behavior of Carbon Steel

authors: Ahmad Raza Khan Rana, Mingzhang Yang, Jamal Umer, Tom Veret, Gragam Brigham

Corrosion under insulation (CUI) is among the key concerns for the integrity of process equipment and pipelines. Various measures to detect and fix the damages from CUI pose significant maintenance expenditures in hydrocarbons processing facilities. The key reason behind CUI is the limitation of thermal insulation to absorb the moisture and soak the underneath metal from wicking action. Other than CUI, trapped moisture in the soaked thermal insulations causes heat loss from process systems, thereby posing the risk of additional damage mechanisms and increased operating expenditures. This study addresses the impact of robust drain openings and insulation standoffs on the CUI rate of carbon steel under four different testing conditions, namely isothermal wet, isothermal wet-dry, cyclic wet, and cyclic wet-dry, respectively. Read more...

Moisture Drainage and Stand-Offs Impact on Insulation Wetting

authors: Ahmad Raza Khan Rana, Graham Brigham

In this study, insulated pipe assemblies with stand-offs and low-point drains were studied for drainage performance. Insulated pipes were soaked with measured aliquots of water followed by quantification of drained water. Patterns of moisture trapping underneath insulation were visualized using moisture detection imaging. A contact-free insulation system with low-point drains achieved maximum drainage efficiency (97%) and the least moisture trapping. Read more...