Case Study on the Failure of a Centrifugally Cast Reformer Outlet Header in a Hydrogen Generation Unit

Abstract Hydrogen Generation Unit (HGU) serves as a critical process plant in refineries, playing a pivotal role in meeting stringent environmental regulations governing the sulfur content in gasoline and diesel. At the heart of this unit is the Hydrogen reformer, employing Steam Methane Reforming for hydrogen production. The reliability of the reformer is critical for ensuring the safety and profitability of the refinery. This paper presents a detailed case study on the failure of a Centrifugally Cast Hot Collector Outlet Header constructed from Centralloy 4859-Cast -20% Cr-32% Nickel alloy, after nearly 20 years of operational service. A comprehensive investigation methodology encompassing visual inspection, stereoscopic imaging, microscopic examination, electron probe microanalysis, and analysis of process parameters was meticulously conducted. The investigation conclusively attributed the failure of the outlet header to high temperature creep Damage. Salvaging of other portions of the Hot collector header was undertaken, followed by a remaining life nalysis (RLA) which included High Temperature Tensile Testing, Accelerated Creep Rupture testing. RLA results indicated an estimated remaining life of 8 years, highlighting the localized nature of Creep damage in Hot Collector header. Furthermore, this paper offers valuable insights into inspection strategies and reformer spare part strategies crucial for enhancing reliability.