Application of UG-93(d)(3) for Rectangular Pressure Vessels/Header Boxes

[minibenny]

I posted a similar thread in another forum, but have not received any responses, so I thought maybe this forum might get more results.

Using fig UW-13.2(c) as a reference, I have been under the impression that MPI or LPI requirements of UG-93(d)(3) would only be applicable to the thicker flat plate, not the abutting shell plate (ts). UG-93(d)(3) and UG-93(d)(4) refer to "the flat plate" numerous times, as though it was written for formed items being welded to a flat plate to form corner joint. However, in the case of a rectangular box, all the plates are flat...

For the top, bottom, and end plates (all ts of fig. UW-13.2(c)), which would not have exposed peripheral edges after welding, MPI or LPI could not be done after welding, but do the weld preparation areas of these flat plates require MPI or LPI?

 

[Tony1t]

I think that it is need to do MT/PT on any remaining exposed surface of the weld joint preparation, unless the flat end plate is forging material.

Interpretation:
VIII-1-07-57

Question: Are the NDE provisions of UG-93(d)(3) required if a forging is used for a flat head or cover?

Reply: No.

 

[GenB]

Not on the weld prep and before welding. Exposed extended surfaces after welding require nde.

 

[minibenny]

Thank you for the replies.
However, I understanding is the outside exposed edges of the flat after welding require MT or PT. This is per UG-93(d)(4)(-b).
UG-93(d)(4)(-a) requires the weld preparation in the flat plate before welding to be MT or PT examined.

Does UG-93(d)(4)(-a) apply to both plates in a corner joint if both plates are flat?

 

[sharmass]

I think you are into manufacturing of rectangular boxes for air cooled heat exchangers.
All top/bottom plate to tube sheet and plug sheet are corner joints Fig UW-13.2(c) and the weld edges require MT or PT as per UG-93(d) before welding. Also peripheral edges of Tube sheet and plug sheet require MT/PT after welding

 

[heatexguy]

LP testing of tubesheet and plugsheet edges is required after weld prep and after welding. Top/bottom plates require LPT only on the short ends after weld prep and after welding (if thickness greater than 0.375"). This is to detect laminations in the plate that may cause the joint to fail in service. If end plates are fully inserted, no LPT required.