The Remnant Life Assessment of the Tube Boiler After 35 Years of Operation

The chapter presents a thorough remaining life assessment (RLA) of a tube boiler, B6201, which has been operational for 35 years at Factory III PT. Petrokimia Gresik. The boiler, designed by Hitachi Zosen Corporation, is a critical component of the sulfuric acid production unit, supplying steam to support factory operations. The assessment begins with a detailed examination of the boiler's specifications and operational parameters, including pressure, temperature, and steam capacity. The methodology employed for the RLA is based on established practices from EPRI and ASME FFS-1, focusing on damage mechanisms and operational conditions. The analysis considers various factors, including operating hours, pressure, metal temperature, and material type, to determine the remaining life of the boiler tubes. The results reveal that most tubes are in good condition, with some experiencing thinning and degradation. The study highlights the significance of considering oxide growth in predicting overheating temperatures for creep calculations, a factor often overlooked in similar assessments. The chapter concludes with recommendations for future inspections and monitoring, emphasizing the importance of in-situ metallography and detailed microstructure inspections to ensure the continued safe operation of the boiler.