•  
  •  
 

Keywords

Design and safety, reliability, sustainability, integrity, design fit-for-purpose, cost effectiveness

Document Type

Research Article

Abstract

A critical incident unfolded within the interconnecting area unit of Utility Facilities, resulting in a significant service interruption to the supply of boiler feedwater (BFW) to the refinery cracker (RC) unit. The disruption stemmed from a leak along a longitudinally welded pipe support, initiating crack propagation along the pipe and fillet weld toe circumferentially. Energy dispersive X-ray (EDX) analysis revealed the presence of iron oxide deposits and embrittled microstructure, exacerbated by hydrogen embrittlement, residual stress around the area of heat affected zone (HAZ) and an increase in secondary load of pipe bridge structure deformation, contributing to the crack initiation and propagation. The root cause failure analysis (RCFA) identified three primary causes of cracking and failure: inadequate pipe support design, poor quality of welding imperfections with numerous welding flaws, and cyclic and intermittent operating conditions. Hence, all these variations in deficiencies and variable operating conditions crafted additional strain on the piping tangentially, accelerating the development of the cracks and leaks. The IRSO Southern-Mechanical team conducted front-end-loading (FEL) and basic engineering design (BED) studies to alleviate these issues, weighing short-term and long-term solutions. After meticulous design, operation, maintenance, and inspection considerations, a prominent solution was refined for further design implementation and site execution. This paper elucidates the factors leading to the crack and failures, the methodology employed in analysis and solution development, and the evaluation and finalisation of the chosen option for a new pipe support type and online replacement methodology. Resolving these failures is paramount for ensuring the long-term reliability of pipework and design integrity of BFW services, safeguarding operational sustainability with elevated safety, and averting future recurrences.

html

Publication Date

30-9-2025

First Page

12

Last Page

19

Download

Share

COinS