Internal pressure and external pressure in pressure vessel

[FATHI]

hi,

ASME SECTION VIII has three divisions, 1, 2, & 3 you have to specify where your requirement are applicable. it's not easy to say and reccommend any formulas without determining the application, it might be in ASME SEC VIII Div. 2 or Div. 1 check first.. the formulas you've mentioned here is absolutely wrong and incorrect. that is not the first step, you have to determine first the allowable stress of material to be used at design temperature and ambient temperature as per ASME SEC. II-D table 5A.. then use the formula mentioned in ASME SEC VIII depending in which division you are using.. whether DIV. 1 or 2.. take note thickness calculation formula for shell in this two division are different.. so be careful.

Thanks,,

Of course I have assumed
design pressure + Design temperature both max and min + corrosion allowance + materials are known and should figure in the process data sheet , befor making a mechanical data sheet or any mechanical sizing

Now you tell me or tell us where are the mistakes , by refering to the codes or text books
I will be glad to learn and correct myself befor induced others in errors

Thanks