Excess Root Penetration
Excess Root Penetration
(OP)
Where can I find in AMSE B31.1 the tolerance or acceptance criteria of excess root penetration?
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
Excess Root Penetration
|
Excess Root PenetrationExcess Root Penetration(OP)
Where can I find in AMSE B31.1 the tolerance or acceptance criteria of excess root penetration?
Red Flag SubmittedThank you for helping keep Eng-Tips Forums free from inappropriate posts. Reply To This ThreadPosting in the Eng-Tips forums is a member-only feature.Click Here to join Eng-Tips and talk with other members! |
ResourcesWhat is rapid injection molding? For engineers working with tight product design timelines, rapid injection molding can be a critical tool for prototyping and testing functional models. Download Now
The world has changed considerably since the 1980s, when CAD first started displacing drafting tables. Download Now
Prototyping has always been a critical part of product development. Download Now
As the cloud is increasingly adopted for product development, questions remain as to just how cloud software tools compare to on-premise solutions. Download Now
|
RE: Excess Root Penetration
ASME B31.1 provides acceptance criteria for a visual examination and for radiography in 136.4.2 and 136.4.5, respectively.
RE: Excess Root Penetration
1/32" of root reinforcement is an extremely tight restriction. What engineering or code requirement would limit this?
Para 127.4.2 in the 2001 code addresses concavity ONLY for density change. Of course I may be a revision behind and am incorrect.
PAra 136.4.2 Visual Examination. refers you to table 127.4.2 whichdoes not appear to address root reinforcement.
Gerald Austin
Iuka, Mississippi
http://www.weldinginspectionsvcs.com
RE: Excess Root Penetration
Regarding C5, the second sentence refers to the "internal condition" of the root surface of a butt weld, which implies to me any possible condition like concavity, drape thru or sharp transitions that could cause an abrupt density change in an RT. The concavity issue is spelled out in the first sentence because this could lead to a reduction in wall thickness beyond the minimum allowed by Code.
RE: Excess Root Penetration
I'm sure there are occasions when the code should be exceeded for engineering reasons and I don't have the education to understand those. I've cut out many waterwall and superheater tubes and have seen a few variations on root contours.
Have a nice day and thanks for the feedback.
Gerald Austin
Iuka, Mississippi
http://www.weldinginspectionsvcs.com
RE: Excess Root Penetration
RE: Excess Root Penetration
GB
RE: Excess Root Penetration
Causing it to be rejected by WHAT criteria?
Thanks
Gerald Austin
Iuka, Mississippi
http://www.weldinginspectionsvcs.com
RE: Excess Root Penetration
Regarding weld root penetration. The Code is very clear on this - there shall be FULL penetration. My opinion anything beyond full penetration at the weld root provides NO benefit, and could be harmful in certain applications. Keeping this in mind, one could make the case that ANY amount of excessive root penetration is NOT acceptable going above and beyond code requirements.
As I stated in my previous post, one has to take into consideration the specific application.
RE: Excess Root Penetration
RE: Excess Root Penetration
Am I reading your statement that the allowabe reinforcement on the inside of a complete penetration butt weld welded from one side is NOT the same as allowed for the outside. If so what is the allowable internal reinforcement per code. I have not looked at a current section I for a few years but I remember the note quite clearly.
We are talking about two ides on t his subject. One os what the code says and the other which is specific to a given design. As far as the code goes both Section I and B31.1 nothing has been given that limits the amount of reinforcement at the root other than limiting to the same amount at the cap.
Someone straighten me out on the code. I have a B31.1 but may be mistaken on the Sec I. If the code text is handy I would appreciate it as I have been mistaken for years regarding the Sec I requirements.
Thanks
Gerald Austin
Iuka, Mississippi
http://www.weldinginspectionsvcs.com
RE: Excess Root Penetration
You are correct. There really is no specific guidance regarding excessive root penetration unless it interferes with RT interpretation.
For welds that are not subjected to RT, the code is silent on this issue and it defaults back to the owner and their requirements.
RE: Excess Root Penetration
SecI has limits. PW-35.1 Inside same as outside. There could be arguments about this of course.
B31.1 Dont think the Code is really silent on this. If I had a problem,would go to the following.
1.Forward
2.127.4.2(C.5) General note(b) in the table does apply,however this is not a good reason for poor welding.
3.136.4 esp.Table 136.4.1
This should start a good argument in anycase. The end result would be that it would take less time to perform good work then argue about bad. Been here once or twice.
Notch effects from excess internal reinforcemnt? This would not benefit anyone. So what reason would there be not to follow SecI and SecVIII on this? The AI may ask you to justify another result.
Well just my opinion.
RE: Excess Root Penetration
By me pipewelder99,
I am in qualituy control and learning
by arguing with the best AIs in the industry,
believe me, I do not always win (more loses than winnings),
Whats the best weld out there: NO reinforsing at all inside or outside period. Of course, you are allowed a little in Sec VIII-1 and in Sec I as well, Sec I is more strict.
GB
RE: Excess Root Penetration
Some additional information that I was able to locate regarding excessive weld root penetration;
Acceptance
The criteria which sets the level of acceptable penetration depends primarily on the application code or specification.
BS 2971 requires that the 'penetration bead shall not exceed 3mm for pipes up to and including 150mm bore or 6mm for pipes over 150mm bore'.
BS 2633 gives specific limits for smaller diameters pipes, e.g. for pipe size 25-50mm the maximum allowed bore penetration is 2.5mm.
ASME B31.3 bases acceptability on the nominal thickness of the weld, for instance, allowing for a thickness range of 13-25mm up to 4mm of protrusion. However, ASME notes that 'more stringent criteria may be specified in the engineering design'.
BS EN 25817 relates the acceptable protrusion to the width of the under-bead as follows:
Severity of service Moderate, D Stringent, B
Limit (up to maximum) h 1mm + 1.2 b h 1mm + 0.3 b
Maximum 10 mm 3 mm
Where: h = height of excess & b = width of bead (see Fig.1)
Avoidance
It is important to ensure that joint fit-up is as specified in the welding procedure. If welder technique is the problem then re training is required.
RE: Excess Root Penetration
Any of you know of any books on weld related failures I could read up on this?
I'm sure between all here we could write a volume or two on code compliance vs fitness for service vs industry practice vs what the inspector wants.
Genb, forgive me for my response above regarding the acceptance criteria for your acceptance criteria. It appears it may have been taken wrong.
Y'all have a nice day
Gerald Austin
Iuka, Mississippi
http://www.weldinginspectionsvcs.com
RE: Excess Root Penetration
RE: Excess Root Penetration
The answer is there is no specific requirement limiting excessive root penetration in B31.1. The owner can specify excessive root penetration above and beyond B31.1 requirements... and yes, you can use specific requirements from other standards if they don't conflict with the requirements in the original standard.