ETD is pleased to announce the successful recent completion of a root cause failure analysis project.
A Middle Eastern based client was experiencing frequent boiler water wall tube failures and some of the tubes have ruptured. Due to the number of frequency of tube failures experienced in boiler water wall the urgency to be able to identify the problem and take palliative measures to stop or reduce the failure is evident. ETD was approached to provide a quotation to perform Root Cause Failure Analysis (RCA) of a Waterwall Tube Sample.
The principle objective of this investigation was to examine the failed tubes samples (two samples from two separate incidents) in order to determine the failure / damage mechanism(s), to assess the micro structural and mechanical condition of the tube material, to examine the internal and external surfaces of the tubes for corrosion / oxidation damage and to examine them for the presence of cracks and manufacturing defects. This led to the identification of the root cause of the failures and allowed ETD to make recommendations concerning remedial actions that may be possible for improving the tube life and avoiding repeat failures.
The scope of the work carried out was:
- Review of the plant operation and tube failure history;
- Visual and dimensional examination of the two tube samples;
- Metallographic examination to determine the failure/ damage mechanism(s) to assess the micro structural condition of material and to identify any micro structural deterioration or defects (cracking, corrosion, etc.);
- Hardness evaluation;
- Chemical analysis of the tube bore deposits to determine the cause(s) of cracking and the chemical cleaning agent most appropriate for the job.
- Deposit thickness will also be determined which also determines if chemical cleaning is required and what type. Recommendations will be made for suitable chemical cleaning companies, if required.
- A full report was then issued detailing the findings of the investigation with all analytical data and photographic records. Including recommendations for appropriate chemical cleaning solvent formulation based on the analytical data.
