There is no minimum distances between adjacent butt joints/welds to my knowledge in B31.1 or B31.3.
When I have encountered such restrictions, they were imposed by the contractor.
It is usually easier to tell a welder that "it" is a code requirement than to explain the company's position or philosophy of imposing such requirements or restrictions.
Consider for a moment the restriction on limiting the width of a weave bead deposited with a low hydrogen shielded metal arc welding electrode. For the most part ASME doesn't impose any limitations on the width of a weave bead. Many contractors limit the width of the weave as a means of limiting heat input. Why, they don't have a clue. They read it somewhere, usually on the inside of the door in the crapper, but it sounded good, so they include it in all their WPSs.
Don't get me wrong. There are times when it is prudent to impose restriction on the width of a weld pass (layer) such as when impact toughness is a concern or limiting the distance between butt adjacent joints. It doesn't look good when the customer sees a butt joint every one, two, or three inches because someone cut the pipe too short the first time and cut it still shorter the second time. The latter is simply poor workmanship. However, as unsightly as it is, it may still function perfectly good. This is a workmanship issue, not a code issue.
"You have to do it because the code requires it." is the biggest cop-out practiced by inspectors and QC departments around the world. The phrase is used almost as often as, "Honestly dear, I'll only put it part way in". Everyone knows you have to put the plug all the way in or the light won't come on!
Best regards - Al
Thanks for the input... I glanced in 31.3 with out any luck. I thought I had seen in either Section IX (9) or 31.3 where the width of the cap could only be a certain diameter.. maybe something like 3T of the tig wire? 1/8 wire coud only make a 3/8 single wide pass cap?
Any input on this?
Al,
Nothing to do with the question that's been posted.
What does exactly "ain't" mean?
I've seen it written and spoken in so much and different circumstances that I've not been able to catch its meaning.
Thanks for the English (rather, slang lesson)
Giovanni S. Crisi
Hi Giovanni!
From wikipedia = "Ain't is a colloquialism and contraction for "am not", "is not", "are not", "has not", and "have not" in the common English language vernacular. In some dialects ain't is also used as a contraction of "do not", "does not", and "did not". The usage of ain't is a perennial subject of controversy in English. Widely used by many people, and found in most dictionaries,[1] its use is often considered to be informal, nonstandard, or improper."
Hello Giovanni;
It is simply poor English grammar.
Best regards - Al
"You have to do it because the code requires it." is the biggest cop-out practiced by inspectors and QC departments around the world."
That may very well be the most astute phrase I've ever read in the Forum. Hope all of our lesser experienced folks read that many, many times.
There is usually (but not always) a rhyme and a reason to what's written in Code... but don't think for even one second that just because something IS written in Code (or on the otherhand, isn't) that it necessarily makes something right or wrong. There are some absolutely brilliant people serving on code committee's, but there are also a bunch of narrow minded people as well. MOST of the time they /we get it right thanks to the consensus process.
Hi
Some codes do limit the distance between welds, but B31.3 is not one of them! Generally this is to reduce residual stress fields from being too close together which may negatively impact the fracture toughness of the material. Mostly this limitation is given in the pipeline codes where there is no mandatory requirement for PWHT when materials start getting thick, but B31.3 deals with the fracture toughness issues by requiring PWHT when the materials become thicker, hence no limits on weld proximity.
Regards
Niekie
Hello all,
Just catching up on some posts.
In the above mention statements reguarding "because the code says so," what would be the "more correct" response?
If a company or customer requires a certain code to be followed, what is wrong with that response?
I'm not disagreeing with you all, just asking a question...
De
I tell them that we don't have time to let you dawdle around keeping it cool enough to not violate the innerpass temp requirements.
Now get back to welding before the GF reams us both out.
There is nothing wrong with stating that the code says so if it does indeed say so. But as Al stated, it is one of the most often used but miss used phrases by inspectors trying to impose their own personal QC and/or agenda.
One also needs to make sure of the applicable CODES (note the plural). Many jobs have more than one applicable guiding force. When on many structural jobs we must make sure from the General Notes and Contract Documents what the engineer has called for in Special Inspection requirements. And you will often find both AISC and AWS D1.1 applicable to the work as well as D1.4 and even D1.3. Then you will notice requirements to IBC that will detail other functions of your inspection requirements. One of my personal observations is how often it gets missed that a job is working to seismic codes, AISC and/or AWS D1.8. These change things more than many realize and can really make a fabricator upset with the TPI when they get caught without the correct welder certs, joint configs, etc.
Bottom line for me is to be able to show it if I'm going to state it that way. And, ultimately, we are to inspect to the Code, not because we do or don't like the way it looks. Does it match the plans with their details for size, location, etc and the code for quality? If not, then say so. If so, I may tell a lead person I don't care for it and they will often change it even if it isn't code enforcable just because they are willing to work with me. But I make it clear I am only standing on personal ground and they don't have to. Most around here have been very co-operative as long as you don't go way overboard and cost them an arm and a leg.
Have a Great Day, Brent
ozniek,
Can you disclose what codes you are referring to?
Jim
AWS D1.1 states that there shall be no more than two girth welds in any 10ft interval of pipe, except as may agreed upon by the owner and contractor.
As an Inspector, the code requirement on weld spacing is irrelevant when there is approved drawing showing the weld locations.
~Joey~
Joey,
thanks for the responce.
D1.1 is not a process or power piping design code. Which was going to be my point to Oniek. The designer is held to the design criterial found in the code of construction. If welds are 6" apart and the designer can prove they are sound by his/her design calcs, then it is not an issue. There are piping urban myths about this issue that have traveled the planet for years. There are certain piping materials that this would be relevent, such as grade 91 material for instance. That is my take on it, although I'm sure someone will be able to shoot holes in it some how. And there, is what makes this forum so cool. You only know what you know until someone else comes along and teaches you something you didn't know.
Thanks
Jim
Dear All
may be I am late...
All of this, is just back to WPS/PQR.. All welding Engineer has been researched to make PQR..So just follow it..
Regards
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