Finite Element Analysis of Reformer Pigtail tubes due to supply ovality condition
Transheat scope
Performing Finite Element Analysis (FEA) to ascertain that the tubes with the reported ovality can be used safely at the design process conditions.
All design documents reviewed by : Client.
Major design attributes
Removal of metal shall not be used to achieve these requirements. But as per tube suppliers dimensional report, this Code requirement is not met and the reported ovality is around 9.5%.
FEA is carried out to ascertain that tubes with reported ovality can be used safely at the design process conditions.
If resulting stresses in the bend region of the tubes are within the code allowable limits, then it can be concluded that the tubes as manufactured can be used safely.
- Comparison of the stress values is also made with the analysis of a normal tube – without any ovality consideration.
- For comparison, purposes, all tubes (with and without ovality) are subjected to the same boundary conditions
Rules of ASME Sec. VIII Div. 2 Part 5 are used with ASME Sec. VIII Div. 1 allowable stress values to determine acceptability of the design
Design conditions : 1.8 MPa and 940oC .
Tube material : Incoloy 800H .