A refinery-wide risk-based inspection and life assessment


  • A refinery in the far-east, dating from the 1940s
  • Many significant changes through its life
  • Currently operating at 115% of design capacity
  • Major components have 50,000 - 250,000h service


  • To provide a Phase 1 combined remaining life study and risk based inspection and maintenance plan
  • To provide a basis for life extension


  • Six units, in the hydroskimming and hydrocracking complexes and the services sector
Level 1 risk based analysis of plant items in the Catalytic Reformer unit.


  • A check-list Level-1 RBI method, based on an early draft of API 581, simplified to suit the client's budget
  • Reliance on the experience of the assessment team
  • Phase 1 life assessment, based on design and historical data, for all high risk component types


  • Components categorised into 5 risk levels
  • Only the CRU reactors identified as very-high risk in the Level 1 RBI - reduced on the basis of HTHA study, creep life calculations and defect assessment.
  • Typically 5-8 high risk component types identified in each unit
Level 1 risk matrix for plant items in the Catalytic Reformer unit.


  • Qualitative prioritisation of component types according to risk level
  • Life management plan developed for all high risk component types
  • Inspection plan developed for all component types, covering scope, frequency, type of inspection and estimated budget


Brear, J.M. and Williamson, J,
“Managing the life of high temperature refinery plant - the interaction between risk based inspection and remaining life assessment”
ERA Conf ‘Engineering Asset Management for Utilities, Industry and Commerce’, London, October 1998. Paper 7.4

Plant Integrity