Pasadena, TX – December 3, 2018

Sudhakar Mahajanam, PinnacleART Senior Engineering Specialist, and Fred Addington, PinnacleART Principal of Corrosion Technology, are published in this month’s issue of Materials Performance (MP) Magazine. Their article, “Underdeposit Corrosion in Crude Tower Overheads,” is featured on the cover page of Vol. 57, No. 12. The article is co-authored by Amanda Barba of the University of Texas Health Science Center. Access the magazine at

MP is published monthly by NACE International and is the world’s largest circulation journal dedicated exclusively to corrosion prevention and control. NACE International is a diverse, global community of professionals who are passionate about disseminating knowledge, enhancing skills and expanding the professional networks of corrosion control and asset protection professionals worldwide. Learn more about the organization at

Article Abstract

Ammonium chloride (NH4Cl) corrosion is an aggressive form of localized, underdeposit corrosion commonly found in overhead equipment and piping associated with crude units. This happens when ammonia (NH3) and hydrochloric acid (HCl) in the vapor react to form NH4Cl salt. Being hygroscopic, NH4Cl absorbs moisture, leading to severe localized attack. Given the unpredictable nature of this damage mechanism, appropriate operational, materials, and chemical controls should to be set in place. This article summarizes case studies where this form of corrosion was observed, along with mitigation strategies.

About PinnacleART

PinnacleART’s vision is to make the world reliable. We do this by designing, implementing, and maintaining comprehensive asset reliability and integrity programs for process facilities in the oil and gas, chemical, mining, pharmaceutical, wastewater, and electric power industries— including national oil companies, super majors, and majors, as well as independents. Our team of talented experts, engineers, and inspectors help clients mitigate risk of downtime and loss of containment; ensure safety of personnel; optimize costs associated with inspection, maintenance and total asset spend; and ensure compliance with regulatory standards. To learn more about PinnacleART, visit, email or call 281-598-1330.