Overall allingment shell to shell 1

[Jman69]

Goodmorning to all, I have been looking in ASME Sec. 8 Diiv. 1 for reference to the allingment of shell to shell over all, end to end. I have three shell's put together and have a deviation in the measurement. I have a string measured at 4" at each end and at one of the middle seam's I have about 3 5/8". I can not find it in the code, if it is even referanced.

Thanks
JM

 

[REGRUMBLE]

You have not given us the other critical measurement. How long (wide) are the three shells. You indicate 3/8" difference which might be acceptable over 30ft (3 10ft wide) but not over 3 pcs 4 ft wide. ASME STS1 indicates 2" over 100ft which is not the same standard but can be used as a reference.

 

[weldtek]

Jman,

You won't find a straightness tolerance in Sec VIII. Most customer specs cover it though.
You may have already considered it, but, another thing you should be checking is roundness because it could be affecting your findings. See UG 80 in Sec VIII.