12" dia drum, SA-53 B - UNEVEN OD
12" dia drum, SA-53 B - UNEVEN OD
(OP)
Hi,
Pls. i want to know, that, if the 12" & 8" std. wall, SA-53 B PIPE was fell down and od changed to oblong, than is this allowed as per ASME IV?
what is allow for UNEVEN OD of pipes as per ASME IV????
Pls. reply me ASAP.
Thanks
MIhir5577
Pls. i want to know, that, if the 12" & 8" std. wall, SA-53 B PIPE was fell down and od changed to oblong, than is this allowed as per ASME IV?
what is allow for UNEVEN OD of pipes as per ASME IV????
Pls. reply me ASAP.
Thanks
MIhir5577





RE: 12" dia drum, SA-53 B - UNEVEN OD
The Code does not distinguish the causes of distortion, they could be thermal, handling, welding, etc.....
RE: 12" dia drum, SA-53 B - UNEVEN OD
Thanks for quick reply. Now i want to know, that if the distortion is more than 1% of the mean diameter?, than is it acceptable or can we fix it?
pls. guide me.
Thanks in advance
Mihir5577
RE: 12" dia drum, SA-53 B - UNEVEN OD
Do you have a copy of ASME B&PV code, Section IV? Yes, you can repair it by various fabrication methods.
RE: 12" dia drum, SA-53 B - UNEVEN OD
The oblong shape you mentioned is not any longer a shell of revolution, hence it will end up with variable internal diameter. It is however, a pressure vessel able to contain pressure. This applies only for a reasonable, gradual change of the internal radius, not for a warp generated by the vessel falling of the crane hook. Provided also that the material was not damaged structurally and you can prove that with various testing methods, you can recalculate the shell thickness based on the maximum internal radius (ie the flat area of the shell). In absence of any dimensional detail of your vessel, it would be speculative to further advise what can you do (re-rate the vessel or discard it and build a new one, etc).
The bottom line is that you might have a reasonable chance to re-use it, but only with the help of a vessel engineer. There could be other issues related to insurance, local government regulations, compliance with the Code for repairs, etc.
Cheers,
gr2vessels
RE: 12" dia drum, SA-53 B - UNEVEN OD
If I read your post right,you suggest by redesign you can wiggle away from the damage and use the vessel. If this was a used or in service item.....maybe. If it is a new item I doubt I would accept it,especialy if it was designed as a "round" vessel to begin with. Just not ethical in my book.
Now if you are talking lots of money,the customer has a deadline,it will not affect final use,and everybody and their brother buys it off in writing.....OK,We can talk.
Since it is pipe...scrap,reform it on a plate roll,jack the damaged area back in shape,or cut the damaged area out and use a flush patch.
Anyhow...just my opinion
RE: 12" dia drum, SA-53 B - UNEVEN OD
I concur with deanc's post. You would have to give pipe with the specifications you mentioned a serious drop to knock it out of round if you now describe it as oblong.
Regards,
RLS
RE: 12" dia drum, SA-53 B - UNEVEN OD
Also, I rather agree with lostsailor. It seems it would take more than just a fall to distort a pipe - like maybe something heavy falling on top of it.
mihir5577: Out of curiousity, what diameter pipe, what's the application, how did it fall (or what fell on it)?
Patricia Lougheed
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RE: 12" dia drum, SA-53 B - UNEVEN OD
You're right, I got carried away thinking of a PV. A small piece of CS pipe, deformed for any reason, doesn't warrant any effort in repair (unless it's flooding your house).
However, I don't regard inethical to try salvage an equipment where people put in there effort and value of design, fabrication, hopes of best performance. I also don't believe that using the Code requirements to salvage an equipment is immoral. It's also not much of an engineer discarding a damaged equipment (without confirmed irreparable damage) on emotional basis. Perhaps somewhere the money comes easy..
Best regards,
gr2vessels
RE: 12" dia drum, SA-53 B - UNEVEN OD
Section IV like other Sections of the ASME B&PV Code do not really single out specific wrought product forms for end use. In this case, the OP referred to pipe being used in reference to an ASME Section IV application. Section IV addresses pipe and tube products for use in pressure retaining applications. What was mentioned above is applicable in evaluating an out of round pipe, drum, header (cylinder) if it is fabricated from seamless pipe, forged pipe or forged and bored pipe.
RE: 12" dia drum, SA-53 B - UNEVEN OD
Didn't say it was immoral,only my opinion on ethical practice.
Over the years I have seen all sorts of things take place and this has resulted in me being rather....well lets just say "skeptical".
deanc
RE: 12" dia drum, SA-53 B - UNEVEN OD
However, where is mihir and details of his pipe. Afterall, he asked for help to doctor the sick pipe. Probably the repair solutions above have covered his requirements.
gr2vessels
RE: 12" dia drum, SA-53 B - UNEVEN OD
one cure would be (if the damage is not sever:
formeit back then PWHT.