2S5: Case Study: Investigation of Crack on Gas Recycling System Vessel

Nu'man Fawzal, Operation Manager, AF Condition Monitoring (M) Sdn Bhd


Crack formation is a highly concerned issue for high pressure vessel application because it could lead to catastrophic failure and worse, lead to sudden explosion. This problem could be accelerated if the equipment operates continuously in high stress conditions such as structural stress and thermal stress. Without any early detection, this could put the employee in a dangerous working situation and operational downtime due to the pressure vessel failure.

This paper presented our investigation and identification of the sources of cracking on vessel ‘manhole’ gas recycling system through the field measurement and Finite Element Analysis (FEA) techniques. By the combination of Operational Deflection Shape (ODS) method and the results from modal analysis, we are able to study the founded problems more in depth and proposed a more effective design solution.

1) Troubleshooting Strategy
2) Correlation between ODS and FEA Study
3) Fundamental of FEA Strategy


Nu’man is a Senior Vibration Analyst certified as Cat IV. He specializes in vibration troubleshooting for rigid rotor and flexible rotor machinery. He is experienced with all type of critical assets from various industry power generation, downstream, upstream and marine. Nu’man is well-versed in routine vibration, operating deflection shape, modal analysis, and in-situ balancing. He has a good background in project management and customer relations. He is involved with Marine Industry for any vibration related issue and Railway Industry for vibration troubleshooting and condition monitoring application.