calc min thick with missing info?

[aliim66]

how to calculation min. thick and remaining life of ASME VIII DIV1 VESSEL when not know orignal thick, corrosion alloawance and material type?

for material i mieght use SA 283 to be more conservative..do u thick that's OK?

 

[GenB]

VIII-div1 Why not trying to get the ASME data sheet from the National Board? if you can't get it is another thing.

 

[pvrerate]

If you have never rated or rerated a pressure vessel I would suggest you hire someone who is knowledgable in this regard. If wish to proceed yourself then first determine if your jurisdiction accepts API-510. If so this standard will guide you in establishing material properties for your calculations. Obtaining all of the required dimensions for the calculations will require an extensive field survey either by laser techniques or tape measure and transit. Judgements will need to be made about the original code of construction in order to establish allowable stresses for components and joint efficiencies. NDE of the equipment may be required to determine weld geometry at such locations as nozzles, i. e. full or partial penetration welds. Further NDE may be required to confirm or set joint efficiencies. Flanges will need to be examined to see whether or not they meet ASME B16.5 dimensions. If not they must be qualified by the selected code. These are some of the more significant items but there are others as well.

To determine remaining life it will be necessary to obtain current thickness readings by UT and/or RT examination. The corrosion allowance available will of course be the difference between the current thickness of a component and its calculated retirement thickness. Determining the remaining life requires a knowledge of the corrosion rate, which often is based on historical data that you don't appear to have. A judgement will be required in this regard.