Pipe Rolling 1

[Hclrag123]

I am working on building a test fixture in the Pipe shape to withstand 3Million POunds of bending force.
The Pipe diameter can be anything between 56 to 60" O.D and wall thickness 1.25" (or more)and 40FT Long. The Yield and Tensile requirement is above 120KSi. Since it is practically impossible for us to procure a single Piece of pipe of X100/X120, i am thinking of getting plates rolled into pipes. In this regard, i have below questions.

1.Can we roll Weldox plates 1.25" Thk to a 60" O.D (or 56" O.D X 1.5" THK)pipe? If yes, can you please provide the contacts of those who can do this?
If no, what is the max thk that can be rolled?

2. Should this is be a cold rolled or hot rolled?

3. IF we roll FOur 10FT sections and weld them together will the strength be equal to the actual single pipe i.e can it with stand a bendng force of 3 Million Pounds? What kind of Welds should be good?

4. Is there any other material which has 120KSi or more tensile and yield, which can be eaily Rolled & Welded, easily procured within united states?

Thanks in advance.

 

[MikeHalloran]

The measure of bending is a moment, not a force, so I'm a little fuzzy on what your fixture actually has to do.


Mike Halloran
Pembroke Pines, FL, USA

 

[Hclrag123]

Hi Mike,
YOu are correct. I mean The Bending moment there due to the force of 3Million Pounds at a Distance of 190". The total length is to be 40FT.

 

[racookpe1978]

Are you trying to make a fixture to restrain the elongation (egg-shaping) of the pipe as it is bent around the fixture? Your ID and OD numbers are not clear.

Or trying to make the bend itself? Draw your problem.

 

[Hclrag123]

Basically i need to build a Pipe that doesn't bend when trying to bend with a force of 3 Million pounds. In this way the equipment itself would be tested for integrity at the full operating pressure/forces.

The O.D is 60" and the Thickness will be based on the Material Yield and Tensile. For ex if i use a pipe of material with 130 KSi the wall thickness can be 2" if i use a 100 KSi the wall may be 4" etc.

But as the pipe becomes thicker and thicker the weight increases and handling becomes a problem. I neesd to find an optimum thickness, material, weight and cost. Hope i am clear now.

 

[MikeHalloran]

Is there some unrevealed reason that it has to be in the shape of a pipe?

Pipe is not the ideal shape for resisting bending moments.



Mike Halloran
Pembroke Pines, FL, USA

 

[Hclrag123]

Hi All,
Thanks for your response.
Yes, it has to be a pipe. Since i cannot disclose teh equiment details, i apologise for this.Any other shaped fixture can damage teh importnat parts of the equipment.

 

[racookpe1978]

Well, why does it have to be a "hollow" pipe?

Assume the "pipe" is horizontal, and is nearly 5 foot inside diameter. If the bending moment is being applied from the vertical, why not weld two (or three) 1 thick plates vertically as an internal "rib" to stiffen the "pipe" from compression?

There is plenty of room to get a manual full-penetration weld on both sides of each rib if they are separated by 18 inches. Difficult, but adequate. If you get a automatic submerged arc weld working in the downhand position of each rib, you can get even closer since you can start the machine at one end of the pipe and run it to the other end "unattended" (Almost.)

Or, pre-fab a rectangular, closely fitting vertical array of stiffeners that only needs to be welded to the ID of the pipe from one side.

You indicate that a solid bar 60 inches in diameter would present "handling problems" ... Yep, sure will. 8<)

 

[Hclrag123]

Hi racookpe1978, Thank for yor suggestion.
Well, If we weld ribs, it is not giving the required moment of inertia.
Since the Bending Stress for a 60 O.D X 1.5" Wall is 127 KSi, the material tensile stress needs be greater than 127 KSi .
I do not have a pipe of that strength.
otherwise if i use a 50KSi Pipe it has to be 5" Thk and weight is humongous of 115,000 Lbs which is impossible for us to handle.
This fixture design should strike a balance b/n weight, cost and strength.

 

[MikeHalloran]

I suppose you could use HY100:

http://www.diversifiedmetals.net/high-strength-alloys.htm?gclid=CJKdueeGkK4CFULd4Aodpz9zgg

You may be able to get it made into pipe at Newport News or Electric Boat.
I'm sure they can roll it and weld it. I'm not sure they can get down to the radius you need, or want to bother with such a small job. Ask.



Mike Halloran
Pembroke Pines, FL, USA

 

[Hclrag123]

Thanks for the Suggestion Mike. I looked at the link you provided.
Looks like the Max dia is 10.5" they can roll with 100KSi material.

However I have sent an email to them asking about my requirement, Will update once i get any response.

 

[Hclrag123]

Hello Mike.
Unfortunately i am unable to find anybody who could roll to my requirements. I tried various other Rolling Mills but no luck.

Any other Suggestions to handle this challlenge?

 

[MikeHalloran]

How many do you need?
Where?

Mike Halloran
Pembroke Pines, FL, USA

 

[Hclrag123]

Hi Mike,
I need One Piece of 40FT or 4 pieces of 10FT welded together to be shippe to USA.
Do you know somebody?

Thanks

 

[MikeHalloran]

Where in USA?



Mike Halloran
Pembroke Pines, FL, USA

 

[MikeHalloran]

You don't need a rolling mill; they make plate.
You don't need someone who makes ordinary pipe.
You need someone who could make a submarine hull.
I used to know some people who did that, a long time ago.



Mike Halloran
Pembroke Pines, FL, USA

 

[Hclrag123]

Hi Mike,
I need in Houston Texas. Can you provide me the details you know.

 

[MikeHalloran]

I started a thread on LinkedIn:

http://www.linkedin.com/groupItem?v...up_most_recent_rich-0-b-ttl&goback=.gmr_92521

No results so far, but the suggestion has been made that a pressure vessel shop could probably do what you want. There must be some in Houston.


Mike Halloran
Pembroke Pines, FL, USA