TWI's Risk-Based Inspection (RBI) planning software, RISKWISE
TM, was recently applied at Nippon Mitsubishi Oil Company's (NMOC) Negishi Refinery in Yokohama, Japan. Working with TLV Ltd, TWI undertook an RBI study using RISKWISE
TM software on the pressure systems within a naphtha hydrotreating unit. The objectives of the study were to optimise equipment inspection plans and identify suitable mitigation measures to reduce the risk of failure.
The risk assessment model within RISKWISE TM converts failure likelihood to a remaining life indicator (RLI). The resultant RLI, together with the evaluation of the consequence of a failure, enables the user to derive equipment inspection intervals.
The results of the NMOC study demonstrated the potential for incremental run length extension after selected equipment modifications, as well as the scope for reduced shutdown inspection effort on a significant number of items. It also highlighted equipment where suggested risk mitigation measures may prove cost-effective.
A senior NMOC spokesperson commented: 'The software is very easy to use, so special training is not required. It enabled us to demonstrate the integrity of our plant using an advanced maintenance system. RISKWISE TM addresses not just those damage mechanisms known to be dominant in causing failure but also other damage mechanisms which may become active.'
The key differentiators of TWI's RISKWISE
TM RBI software system are:
- user-friendly implementation process, relative to other RBI systems
- unique reliability-rule based evaluation to derive safe inspection intervals
- risk mitigation module which allows users to assess a range of risk management actions to meet inspection interval targets
TLV Co Ltd is TWI's RBI technology partner in Japan. For more information about RISKWISE TM, please contact TWI at: riskwise@twi.co.uk
Criticality ranking of damage mechanisms in a fired heater
