×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Header attachments, weldolets etc.

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.

RE: Header attachments, weldolets etc.

Are you adding the weldolet onto the tee? Then no, not allowed, unless you re-qualify the thee per 304.7.2, as it is no longer a standard B16.9 tee.
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.

Codes are not normally in the business of allowing or not allowing things like this and there are many many similar threads about proximity of welds.

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.

(OP)
Many thanks, I will try and get a picture and send it on my next post.
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.

Quote (SteveS58)

It would be nice if there was something in the ASME codes.
ASME Codes are not a cookbook type set of rules that covers everything. Read the foreword of the appliacble ASME standard.
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.

Quote (SteveS58)

I seem to remember reading something about not welding within 4 x the pipe wall thickness to an existing welded joint.
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.

Quote (SteveS58)

Unfortunately I don't have access to any of the ASME doc's
If you dont have access to the applicable Codes, make sure to get a copy of the applicable codes by buying them.

Quote (SteveS58)

I am new to this position and just setting up on a site still under construction.
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.

Agree 100% with XL83NL.

RE: Header attachments, weldolets etc.

Also agree - for things stating construction issues you need to scour the company or design specification issued to the contractor for any minimum distances.

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.

(OP)
Thanks Gents.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources