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

Weld vs Flange connection

Weld vs Flange connection

Weld vs Flange connection

weld or flange connection, which one is preferred in the high-pressure process condition

RE: Weld vs Flange connection


But not always practical and makes replacement of repair of items very difficult.

Why do you ask?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Weld vs Flange connection

Welded, but high temperature and high pressure applications may have issues with some dissimilar metal welds that can , in some cases, be better served by the use of a "compact flange".

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

RE: Weld vs Flange connection

Welded or press-mounted joints.
Flange bolted joints will have to be very large and thick to withstand high pressures.

* Finding a solution is great * Knowing how to implement it is fantastic * Believing it is the only one and best is naive ?

RE: Weld vs Flange connection

Nobody has mentioned cost. Each joint requires purchase and installation of of 2 extra pieces, with probably 1 additional weld and many bolts, nuts and gaskets. You should have a reason (see above) for buying them.

Flanges should also be avoided where leaks are undesirable, or dangerous for many reasons.

RE: Weld vs Flange connection

I have a few cents to add based on recent experience but I’ll wait for the OP to first joint the discussion and show some appreciation for the input provided so far.

- You never get what you expect, you only get what you inspect.

RE: Weld vs Flange connection

We have installed many large pressure vessels and it was easy to convince the owner not to have flanges. Just asked them how many times they indent to actually unbolt the flanges and answer was usually never. They then saved on the cost of the flanges and no future leaks to deal with.

RE: Weld vs Flange connection

More details, better answers.

As this is a cost/benifit calculation, NOT a pure technical one, we need a lot more information. 'High pressure process conditions' in a forum for 'pipeline and fluid Mechanics' can be valves for anything from gas, water, oil to anything else. (Not only petroleum related as some always seems to assume.) Pressure class and diameters might also vary widely.

From my experience you may note down some general points:

Smaller sizes, not very often operated, non critical for continious operation, repairable without demounting from pipeline
larger number equal valves: all separately lean in favour of welding ends.

We must take into consideration the requirement for continous uninterrupted operation time, cost for repair and shutdown. I have supplied high pressure class valves up to several tons. (Hydroelectrical and drinking water pipelines if you wonder). For high pressure class valves of larger dimensions the process of welding in place, and not at least removing and replace, would be costly and highly impractical.

End types regarding to class, size, fluid and precess requirements and cost have to be considered for each case.

RE: Weld vs Flange connection

Linua Jr.
What pressure and process we are talking here? The design will depend on the risk to environment, personal and economic loss.


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


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