Minimum space between two weld on pipe 1

[mecaniquetuyauterie]

Hi

What is the minimum distance between two circumferential welds on pipe.Wich code cover that topic?

Thanks

 

[BigInch]

What are you building? Firstly, code requirements depend on what you are building and what codes apply to your construction.

For example, API 1104 is appliable for general welding quality results and acceptability for pipeline welds.

In general there is little that anything says about the allowed closeness of two welds, other than the recommendation that heat affected zones should not overlap.

Only put off until tomorrow what you are willing to die having left undone. - Pablo Picasso

 

[SJones]

http://www.eng-tips.com/search.cfm?pid=0&action=Search&q="distance+between+welds"

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[Shinexx]

Codes are silent on this issue. However, as a designer you should design putting weldability into consideration. I used to consider (2*D) for line 4inches and below for bigger lines I use the (1*D).

 

[brimmer]

3*d in the code where I am

 

[Duwe6]

Since welds are made to a qualified WPS/PQR are typically stronger than, and always as strong as, the basemetal, ASME sets no limits on weld spacing.

 

[BigInch]

That would make it impossible to weld any ell with a turn less than a 180[°]

Only put off until tomorrow what you are willing to die having left undone. - Pablo Picasso

 

[iken]

In reply to
"Since welds are made to a qualified WPS/PQR are typically stronger than, and always as strong as, the basemetal, ASME sets no limits on weld spacing" - I would disagree. With pressure vessels there is allowances for weld efficiencies, which implies welds cannot be stronger than the base material, or as strong as. This may not be the actual fact in the real world, but for engineering it makes sense. The strenght of the weld is limited to the weakest part - so if the base material is weaker, then this is the limiting factor. Also, not all welds are free from inpurities - hence I guess why there is a weld effeciency allowance.

 

[11echo]

It really doesn't matter "IF" you're prepared to deal with the over lapping heat effected zone! My end of the world we used 3" (not diameters) between welds WITHOUT doing a PWHT (post weld heat treat) on piping systems that require it. We do these close welds on gravity drains without any PWHT, so it depends on the piping system. I have retro-fitted existing piping systems where the tie-ins were closer to existing welds on very high pressure systems, BUT we did the PWHT and had no issues.

 

[toohotforme]

I was just looking for such a discussion! - and here it is.

11echo, you say "in your end of the world". Do you refer to local rules, sound engineering practice or a Code? If the latter, what is the Code? - and where is your end of the world? (Generally speaking e.g. USA, North Sea etc.)

brimmer says 3*d in the code where he is. What is that Code?

I have looked through ASME B31.3 - 2010 and cannot find anything on this. It makes sense to have a rule of this type.

Thanks.

 

[brimmer]

The code where I am is CSA Z662

 

[pennpiper]

This question has been asked many, many times on this and other forums.
Go to the "Search" button in the header section and type in your question before you post it on the forum

I typed in "minimum distance between welds" and got lots of information.