Authors : Mohammed S. Al-Robai; Abdulrahman A. Alkhateeb

Volume/Issue : Volume 10 - 2025, Issue 7 - July

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DOI : https://doi.org/10.38124/ijisrt/25jul1697

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Abstract : This paper presents a real case study of a structural integrity assessment of a Low-Pressure Production Trap (LPPT) at a Gas Oil Separation Plant using Fitness-for-Service methodology. The equipment, constructed from carbon steel (CS A-516 Gr. 65) with a nominal wall thickness of 18.0 mm, operates in a sour environment prone to hydrogen-induced cracking (HIC) and step-wise cracking. Automated ultrasonic testing revealed HIC and inclusions at depths ranging from 7.3 mm to 14.8 mm, with step-wise cracks up to 2.2 mm in height. Fitness-for-Service assessments, using API-579 Level 1 and 2, confirmed the equipment’s fitness for continued service, provided regular monitoring and protective measures are implemented. This study underscores the utility of Fitness-for-Service in extending the lifecycle of aging infrastructure while ensuring operational safety.

Keywords : Corrosion; Fitness-For-Service; Hydrogen-Induced Cracking; Sour Service.

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