DOES ASME SEC VIII DIV.1 ALLOW NOZZLE INSIDE PIPE MACHINING? 1

[staticmh]

Good day Folks!

Hope you doing all well.

I've been faced one case, where my vessel is having NPS-10" nozzle and coupled with pump assembly with blind flange.

Issue is that pump have the submersible assy, which outside dimension is 245mm.

We procured the pipe NPS-10" SCH-80, which ID is 242.82mm. now if we use the NPS-10" SCH-80 the pump assembly cannot be insert through the pipe due to lesser inside dia as compare to NPS-10 SCH-80 pipe.

However, Vessel is U-stamped and we intent to machine it up to sch-60 thickness (12.7mm) & Inside diameter 247.6mm as per our understanding.

Can anybody advice me whether ASME SEC VIII Div. 1 allow to machine the nozzle pipe (SA-106 Gr.B , 3.2 certification, NACE Compliance) material or not. Please refer the code clause we have to address with AI.

Thanks in advance.

 

[staticmh]

@SnTMan

Thank you for your valued feedback.

Infact even i also know it is possible but my ASME Inspector (AI) is asking about the solid justification.

 

[staticmh]

@r6155

Instead of outside diameter, Our main concern is to maintain the inside diameter for the successful insert the pump assembly through it.

 

[staticmh]

@SnTMan

UW-13 (i) talk about the tapper transition for the flange and pipe weld join in case if the pipe and flange are not on same schedule. Its already under considered on other nozzles but on this case it does not apply.

My concern is about to maintain the both flange & pipe at schedule -60 by machining a schedule-80 pipe & Flange.

 

[SnTMan]

staticmh, yes you may machine the ID's if all other requirements are met. You will not find an explicit statement saying this is permitted. You will not find an explicit statement saying it is prohibited.

Good luck,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand