×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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!

*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

Welding ¼” schedule 80 Steel Pipe
4

Welding ¼” schedule 80 Steel Pipe

Welding ¼” schedule 80 Steel Pipe

(OP)
Full penetration; OD = 0.540” wall thickness ~ 0.119”; carbon steel. Anybody successfully done this?

The few such pipes I have seen cut open had bores that were not real close to circular or concentric ... I'm unsure if those were exceptions or the norm.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

RE: Welding ¼” schedule 80 Steel Pipe

Considering that the wall is -12.5%/+15 or 20% (depending on the spec).
This would be a real challenge.
I have watched fitters measuring walls and rotating pipes to get the heavy sides/light sides to align with each other.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy

RE: Welding ¼” schedule 80 Steel Pipe

(OP)
OD dimension will be good (I never see much variation there), and we can ream out the ID, but that won't eliminate eccentricity. We will have no freedom to rotate for best-fit.
Has this ever been done autogenously by orbital welders? I think PAW might do better than GTAW at this thickness.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

RE: Welding ¼” schedule 80 Steel Pipe

We use this pipe diameter and schedule for our standard "small diameter" test. The biggest problem I see is that acceptable root reinforcement can greatly reduce the ID of the pipe, which could be an issue if you want stuff to flow through it. Our other problem is that it's so small, it's easy to over heat and get porosity, which with that small wall thickness has very little tolerance for. Don't know if that helps you though. I don't see to many fit-up problems because we are using the same piece of pipe for both ends of the test after cutting, so it will fit-up nice.

RE: Welding ¼” schedule 80 Steel Pipe

IM,
Not very good with imperial so will reply in metric.
Your C/S pipes are 13.7 mm OD x 3 mm WT.
I have seen literally hundreds of S/S and Inconel tubes (12.7 mm x 2.1 mm) welded with Orbital and no significant issues regarding ovality or concenctricity.
Not sure if that helps at all as you have a slightly thicker WT,
Cheers,
Shane

RE: Welding ¼” schedule 80 Steel Pipe

I think you might be able to do it with orbital GTAW, but it requires proper equipment and strict control of weld edge preparation, which can be a pain in the ass with piping fitting (which I'm assuming to be used here since the OP referred to pipe dimensions rather than tube). I'm also not sure if it can be autogenously welded at these dimensions, although I think it can be done.
A lot of the process piping we do in our plants is tubing, sometimes orbital welded. As DD mentioned, 1/2"x0.065 or 0.083" is nothing special at these dimensions.

Huub

RE: Welding ¼” schedule 80 Steel Pipe

We have weld this exchangers pipes without problems with TIG or GTAW.

luis

RE: Welding ¼” schedule 80 Steel Pipe

(OP)
I should have fully clarified in my OP, this is a pipe-to-pipe weld.

CWEng - Excessive root reinforcement would be a problem, and it is pointing us toward automation.

DekDee - This is not tube and it is not stainless. We also have that challenge but we are following the standard biopharma/semiconductor industry approach.

XL83NL - It is definitely pipe, heavy wall. We can develop all necessary tooling to achieve consistent and accurate joint preparation and fitup.

0707 - This is not a tube-to-tubesheet arrangement if that's what you mean.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

RE: Welding ¼” schedule 80 Steel Pipe

We did this manually with GTAW on CS tubing with one very good welder who was able to qualify. Only a few welds were required to ne made.

RE: Welding ¼” schedule 80 Steel Pipe

I would think that you could set up multi-pass orbital to do this.
So this is 0.104" min wall. And you bevel the end about 0.065" deep. the looking at the end you would have a root land that ranged from 0.040" to 0.060" (or a little more) around the pipe. Does that sound manageable?

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy

RE: Welding ¼” schedule 80 Steel Pipe

If you can't tolerate root reinforcement, i.e. penetration into the bore, you're going to be in trouble.

Especially if it's seamless, you can count on the need to back-bore the ID prior to welding, if back-boring it to remove excessive root reinforcement isn't an option.

It is possible. Automation will help, but this isn't a weld you'll be able to do without filler metal in my opinion.

RE: Welding ¼” schedule 80 Steel Pipe

Would it be possible to put a weldable joint ring in place and TIG weld the first pass. then continue with Mig or stick welding?

B.E.

You are judged not by what you know, but by what you can do.

RE: Welding ¼” schedule 80 Steel Pipe

Quote (IM)

Excessive root reinforcement would be a problem, and it is pointing us toward automation.
Automation cannot adjust on the fly for hi/low, differences in root opening or the depth of the small vertical plane at the tip of the bevel (we call it the "nose", don't know in eglish) ... If you go for automation, prep needs to be perfect and each time identical.
I would choose for some advanced welder training, and if possible, welding on a rotational positioner (= manipulator).
A good welder should be able to do this without excessive weld reinforcement (easily <= 1 mm, probably even <= 0.5 mm is doable), even in position and with small diameter tubes.

RE: Welding ¼” schedule 80 Steel Pipe

(OP)
kingnero ,
I fully understand the enhanced fitup demands of automated welding. I will go in assuming the bore is neither round nor concentric, so tooling to provide consistent weld preps in the field is a prerequisite.
I've come to the conclusion that this is probably not easily doable with an autogenous welding process.

EdStainless,
I like your suggestion of a v-groove prep with depth about half the wall thickness. Field tools for that are available.

However it gets welded, I believe heat buildup will be a big challenge.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

RE: Welding ¼” schedule 80 Steel Pipe

Autogenous will be indeed nearly impossible, but autogenous is in general not my first choice, even in C-steel.
If you can get consistent weld preps, automation with filler metal will be doable. For these weldments you should aim for ~0.3kJ/mm, so heat build-up will be very manageable.

RE: Welding ¼” schedule 80 Steel Pipe

We have done it manually with GTAW on air coolers tubes, where we have to add some small pipe sections to have tubes with the needed length.

regards

luis

RE: Welding ¼” schedule 80 Steel Pipe

You may have to ream the pipe to ensure the ID is concentric and true, but once the fit is consistent from one joint to the next, orbital welding should do the job. the root can be completed as an autogenous weld, and a second layer can be completed with filler metal using GTAW.

Best regards - Al

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! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close