Specification for bolt hole alignment, vessel out-of-roundness

[agauth3]

I am investigating a quality issue with an ASME coded vessel supplied to my company that was built per ASME Sec. VIII, D1 2007. It is a 8.5' wide x 19' long drum with a flanged head on one end. The vessel was delivered with the head assembled to the drum and upon inspection, we found that the head flange bolts were all in a severe bind. They had to be cut off because the drum body flange was out of round causing the bolt holes to be severely misaligned. This is a vessel that will routinely be opened for process cleaning presenting a substantial problem for operability, thus we will have to have it repaired. Is there any specification in Sec VIII Div I (or any other codes for that matter) that might cover this issue and give us a leg to stand on with the vendor?

 

[vesselfab]

Did your inspector see this bind at hydrostatic test or did he measure the flanges for roundness?

code out of roundness is 1% of diameter from big diameter to little diameter. this vessel could be 13/16" out of round.

were the flanges custom made plate flanges or forged or what?

was the vessel pwht

if it was my company that made this...it would have never made it past hydro test.

many things could have cause the problem and most likely a light flange with no hub on it was deformed during welding.

but the hydro crew should have said something about it.

 

[fegenbush]

vesselfab,

You are correct that UG-80(a)(1) calls for an out-of-roundness of 1% for vessels subjected to *internal* pressure. However, since agauth3 did not specify whether the vessel is subject to internal or external pressure, I would refer him to UG-80 to determine the permissible out-of-roundness, as UG-80(b) has much tighter tolerances when the vessel is subjected to external pressure.

Fegenbush

 

[vesselfab]

YEPPERS

sweeps must be made roundness is much tighter

Normally a drum is not stamped to external pressure
but is designed to withstand for steam out.

 

[racookpe1978]

Seems like the issue can be resolved not only with a "code requirement" but with the requirement (in your spec's) that the flange be operable = be removed with no binding and in the 1% circularity (no over-drilled or re-drilled holes!) so that the flange and cover plate match.