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Up Topic Welding Industry / ASME Codes / Piping (B31.3)
- - By Joey (***) Date 04-09-2013 03:35
What is your opinion with this pipe shoe design (B31.3)? The initial length of 150mm was found short, so the contractor decided to increase by joining two pcs together to make it 300mm. The designer has approved the middle splice without welding.
Attachment: pipeshoephoto-1.pdf - pipe shoe (971k)
Parent - - By Jovi Zhu (**) Date 04-09-2013 03:56
Is that a non-pressure retaining attachment welded on the pipe?
That is all up to the designer~
Parent - - By Joey (***) Date 04-09-2013 07:48
Correct! But the designer says you are free to comment :razz:

~Joey~
Parent - - By Jovi Zhu (**) Date 04-09-2013 08:15
Hah~:cool:

Free comment? well~ I'm kinda curious about if preheating was required prior to that attachment welding and if preheating was applied as required~
Parent - - By Jovi Zhu (**) Date 04-09-2013 08:16
as well as the prior-cleaning process before welding~:roll:
Parent - - By Joey (***) Date 04-09-2013 09:38
Huh:eek: designer says your comments have nothing to do with the pipe shoe design :lol:

~Joey~
Parent - - By Jovi Zhu (**) Date 04-09-2013 12:33
Okay~
It time for the designer of this to give some comments.:cool:
Parent - - By Shane Feder (****) Date 04-09-2013 13:30
Joey,
What is the point of this question ?
The designer can nominate anything he or she wants - as long as it is code compliant (which I cannot see why it wouldn't be) then it is fine.
May look a bit strange but I have seen much worse that is deemed acceptable,
Regards,
Shane
Parent - By G.S.Crisi (****) Date 04-09-2013 18:36
It might be acceptable to the Code, but it's definitely not according to Good Engineering Practice.
What's Good Engineering Practice? Well, that would start a long, long thread in this Forum.

Giovanni S. Crisi
Sao Paulo - Brazil
Parent - - By ssbn727 (*****) Date 04-09-2013 18:26
That may be so but, it certainly doesn't look like something I would purchase because there's no weld to join the web of each piece together and I would at the very least insist on that before approving it if I were the customer then again, that's just me...

If I might add, would you be so kind to show us a better picture of the weld to the pipe that attaches the pipe shoe design? Also what if any amount of vibration will this pipe shoe be exposed to... And are the beams & the welds going to be painted or coated with some sort of corrosion protection if this is going to be exposed to a moisture rich environment?

Respectfully,
Henry
Parent - - By Shane Feder (****) Date 04-10-2013 01:46
Giovanni / Henry,
I am definitely not condoning this work.
I agree completely that it does not look good and it is not good engineering practice but both of those comments are not cause for rejection.
IMHO the least it should have is a seal weld to prevent rust leakage but we don't know if it is even going to be painted.
If seal welding is not addressed in the relevant code, relevant project specifications or relevant contract documents how do you reject it ?
"I don't like the look of it" will not wash very well,
Regards,
Shane
Parent - - By Joey (***) Date 04-10-2013 04:26
Shane, the designer was from a 3rd party company. I raised this question to get others opinion. Just to make sure that he don’t find my comment suck up to the boss.

The designer made a wrong design by providing insufficient size (length) and when the contractor told him that they’ve already cut and prepared many based on his initial drawing, the designer quickly approved the contractor’s proposal of joining the two pieces without welding the middle splice.

My concern is similar to Henry. The gap on splice connection is susceptible to corrosion if not seal welded. Since the piping is allowed to have free movement due to thermal expansion and contraction, the pipe shoe should be designed to resist any friction caused by non planar surface. To have one piece of correct size is definitely better than joining two pcs, which you have to ensure free from hi-low / misalignment. Any improper restraint conditions should be reported and corrected.

Sorry Henry, I dont have anymore photos that will show the fillet weld (6mm) connection of pipe shoe to the pipe.

Thanks
~Joey~
Parent - By MBSims (****) Date 04-21-2013 15:52
Not good design practice. I could go along with not welding the qeb, but the flange should be welded and ground flush to make sure it doesn't hang on the edge of the support beam.
- By 803056 (*****) Date 04-22-2013 15:25
You ordered a car with four tires. You didn't say they all had to be the same size and you didn't say they all have to hold air.

The code stipulates the minimum requirements. Any additional conditions, requirements, or expectations must be specified in the project specifications. All that being said, the Owner has last word since he is holding the gold, I mean check. That gives the Owner a lot of persuasive power.

The question is, “Who do you represent? The Owner/Company or the contractor?” If you represent the Owner/Company, then you have cause to question the design and the construction of the system and all the components in the system. All inquiries should be in writing and all responses should be in writing. Verbal communication is often the victim of amnesia when the crap hits the fan.

Al
Up Topic Welding Industry / ASME Codes / Piping (B31.3)

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