Failure analysis in heat exchanger tubes from the top system of the regeneration tower of the hydrotreatment unit in an oil refinery: a case study

ABSTRACT This paper presents a failure analysis performed on tubes of heat exchanger. Heat exchangers are among the most common equipment in an oil refining industry, as transfer is one important and processes chemical petrochemical industries. The analyzed was condenser top system diethanolamine regeneration tower naphtha hydrotreating unit refinery. tubular bundle consists 78 ASTM A213 Grade 316L specification, with 19.05 mm diameter 1.65 wall thickness. subjected to aqueous flow H2S outside cooling water inside. After scheduled general shutdown July 2011, after six years continuous operation, loss thickness several observed. result indicated that, through visual inspection, corrosive process occurred from inside tubes. eddy current test active corrosion rate 0.16775 / year. ultrasonic inspection internal rotating (IRIS) confirmed presence perforated tubes, consequent containment. Amine identified basic mechanism, aggravated by DEA concentration higher than 20 wt.% equipment. In October 2019, this exchanger were replaced proposed solution mitigate problem dilute washing water, obtain amine concentrations below 5% mass beam