STRESSED BRANCH CONNECTIONS, NEED EXPERT's OPINION 1

[SmallInfo]

Hi Experts
I am practicing stress on this cold flare simple line of Sch. 10S but the problem I am facing here is at branch connections, each branch connection is stressed more than allowable, I am trying to control it by changing type of supports but no luck. Need expert’s recommendations for attached CAESAR II file, stressed node numbers are also provided.
Thanks

 

[LittleInch]

Bigger connections then a reducer. So a 4" weldolet then a 4 x 2 reducer for e.g.a 2"branch connection

What sizes?

Or brace the connection to the main pipe. This one is a bit extreme, but gives you the option commonly used.

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

 

[SmallInfo]

Thanks, but here some tees are equal of 8" and some are just reducing 8x6". How to manage stress in this case?

 

[LittleInch]

Where's the differential movement coming from?

Is the header moving or the branch moving?

Guides? supports? anchors?
I can't read C2 files so you need to post some more exact drawings of what your system looks like.

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

 

[StressGuy]

The problem you're facing is that this model is a complete mess.

You're imposing arbitrary movements at your connections along the branches (nodes 1411, 1491, 5411, 5491) with no flexibility to absorb those movements.

Along the branches, you have multiple directional anchors in-line with each other (1341 against 1371 against 1451) and (5341 against 5351 against 5431 against 5441 against 5501). You can't have anchors in line with each other like that without expansion loops in between them.

Instead, you should have no more than one anchor on those two branches, and they should be located as close to the header to push expansion away from it.
Nodes 10 to 100 are what I'm calling the header and the branches are ones with the node ranges in the 1300-1400's and the 5300-5400's)

You're not going to fix this with supports, it needs to be flexed up.

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

"All the world is a Spring"

All opinions expressed here are my own and not my company's.