Bottom plate Replacement_Heat Traetment

[nabeel3]

Dear All

My company got a Tank Job , Carbon steel Water Tank , to replace the existing Bottom plate . We plan to cut one existing shell to remove and insert the new bottom plate. Is stress relief heat treatment required after welding the shell . Is it depend on the shell thickness

 

[HTURKAK]

My points are ;
- Pls look API 653 , clauses 9.10.2.1.1 through 9.10.2.1.6. The common practice is shell slotting (complete severing of the tank wall ) 100 mm above the bottom .
- A doorsheet is opened on the shell to take new plates etc. inside the tank . The new bottom is placed on spacer material ( sand or concrete ).
- If you choose sand for spacer material , you will need C.P. for external corrosion.
- This subject has been discussed in past with several threads. Pls search the forum .
- You did not provide a lot of info here. What is the dimensions of the tank, what about the roof type and internal supports of the roof ?
- PWHT in general for tank business required for shell manholes, nozzles which are having substantial amounts of weldments.

 

[nabeel3]

Thank you for the reply. I will check. The tank is 15 m dia, fIxed roof