Header attachments, weldolets etc.
Header attachments, weldolets etc.
(OP)
Headers and weldolet attachments
Is it allowed, by code, to attach a weldolet to a header, under the following conditions.
Please note: the position of the weldolet is as follows:-
The header is made up of two pieces of 10" pipe, joined together with a 10" tee-piece. Weldolets are fitted on the centreline / weld of the tee-piece to pipe welds.
Any advice is greatly appreciated.
If required I will try to get pictures to better show the issue.
Is it allowed, by code, to attach a weldolet to a header, under the following conditions.
Please note: the position of the weldolet is as follows:-
The header is made up of two pieces of 10" pipe, joined together with a 10" tee-piece. Weldolets are fitted on the centreline / weld of the tee-piece to pipe welds.
Any advice is greatly appreciated.
If required I will try to get pictures to better show the issue.





RE: Header attachments, weldolets etc.
Or; are you adding the weldolet over a circ seam? Why? Why not just next to the circ seam?
A sketch would certainly help. Please also include relevant design data (such pressure, temperature), material, design code, etc.
RE: Header attachments, weldolets etc.
A picture would be great, but if I understand you correctly you're planning on inserting a ?" weldolet right on top of a 10" header circumferential pipe weld. No idea what welding procedure or testing you can use for that.
On the face of it sounds like a terrible move and all sorts of issues of welding in HAZ and mixing of weld metals, but probably not specifically permitted or not permitted.
If it's that close to a tee though you may be compromising the design of the fitting and creating a stress concentration on the tee for which it wasn't designed.
If it doesn't look right it isn't right.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Header attachments, weldolets etc.
Your assumptions are correction, ref' on the circumferential weld. I obviously agree with you, which is why I was asking for advice on my concerns. It would be nice if there was something in the ASME codes. I seem to remember reading something about not welding within 4 x the pipe wall thickness to an existing welded joint. Unfortunately I don't have access to any of the ASME doc's, as I am new to this position and just setting up on a site still under construction.
RE: Header attachments, weldolets etc.
Think of it as follows; if you buy a new shower for your bathroom, which comes with a manual on how-to to install it, and you install the shower acc. the manual, that doesnt mean you have become a professional plumber. It takes years of experience and mentorship to understand what it and is not in the codes, and how to address those things not in the codes.
This is not part of the ASME codes. Some rules of good engineering practice (Recommended Practices), or client specs, may spell out such requirements, which typically pertain to hardenable materials. Austenitic materials are less prone to such issues.
If you dont have access to the applicable Codes, make sure to get a copy of the applicable codes by buying them.
In that case you better leave these questions to someone experienced in this field of work, like a pipe stress or mechanical engineer, and let him do the work. You obviously are not the right one answer this question.
RE: Header attachments, weldolets etc.
RE: Header attachments, weldolets etc.
Or just reject the design / workmanship and hold your ground.
Things like 4t and 0.5D minimum distances are construction issues not normally covered by the design code.
Search minimum distance welds on this site and you'll see many opinions, but very few, if any "code" requirements or limitations.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Header attachments, weldolets etc.