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ER
April 11, 2017, 13:52
Guys... I know some of you are in the "heavy" industries, and I'm in need of a supplier....
I'm in the polymer extrusion industry as an OEM, doing custom equipment between the extruder and die. We have a customer who wants us to duplicate part of their system into a new system were building for them .
What I'm looking for is a supplier who can bend 2.5"IDx4.25"OD(7/8" wall) tubing, or supply welded sections/elbows tested and certified up to 11,000psi. The customer's existing bends are on a 1'-10" radius and they'd prefer to stay around that if possible.
Ideas???

jhend170
April 11, 2017, 16:26
Not sure if they need to be in your area, but I grew up right by these folks. Might be able to help...

http://www.hpbenders.com/

ER
April 11, 2017, 19:56
Thanks! I`ll check them out. There is nobody I`ve found in the southeast that can do it. I kinda expected to have to travel to find someone.

martin35
April 12, 2017, 14:14
Houston Texas would have a large number custom fabricator's who supply the aero space and petrochemical industries with certified pressure vessels and fitment's.

Slow
April 13, 2017, 21:47
used this company for some custom bending, nothing special, they did good work in a short time frame at the time.


http://www.tubetecbending.com/




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STG_58_guy
April 13, 2017, 21:57
It seems like it would be impossible to bend a tube with such a thick wall compared to the diameter. I'd love to know how they do that.

martin35
April 14, 2017, 11:09
It seems like it would be impossible to bend a tube with such a thick wall compared to the diameter. I'd love to know how they do that.I know of and never heard of a simple mechanical process that would not fatigue or diminish the heavy wall Hoop Stress parameters required to work at 11,000 psi.
A welded fusion and annealed fabrication is probably the only solution.

ER
April 14, 2017, 20:59
I know of and never heard of a simple mechanical process that would not fatigue or diminish the heavy wall Hoop Stress parameters required to work at 11,000 psi.
A welded fusion and annealed fabrication is probably the only solution.

Somebody has bent it in the past, or so says the prints sent to me by the customer. Eastman Kodak had them done somewhere (in Texas we think) and we were trying to find the original vendor or a suitable replacement. Moot point now since the customer decided to reuse the existing pipework and just add a short straight piece to adapt to our equipment. The line is in England now, but was once in TX. With only a 2.5"ID, hoop stress isn`t much in the grand scheme of things even to 11,000psi.

STG_58_guy
April 15, 2017, 02:56
I know of and never heard of a simple mechanical process that would not fatigue or diminish the heavy wall Hoop Stress parameters required to work at 11,000 psi.
A welded fusion and annealed fabrication is probably the only solution.

I've bent enough steel to know it wouldn't be easy. With high quality sheet and plate you have to have a pretty generous bend radius to keep the outer surface from cracking. Tubing wants to buckle when you bend it. Again, a large bend radius compared to the wall thickness is required. I believe you could easily compromise the strength of thick walled tube bending it like that.

Maybe if you a a 3 foot bend radius...

martin35
April 15, 2017, 15:42
A heat forge and bend combination comes to mind for managing the plasticity of reforming a tube to a given radius while maintaining the materials uniform flexibility,,, at the pressures mentioned steel and every material known to man will stretch measurably.
These known physical phenomenon are in part the basis of pipe certifying agencies criteria like ASTM.

NASA has developed composite materials and methods for high pressure piping with variable temperature and pulsation parameters that are not generally used except in space exploration because of cost considerations,,, cost is always based on the need and the ability to pay.

One alternative I might suggest is the use of a thread driven autoclave style fitment in the area of a piping run requiring a radius,,, these are used for up to 150K psi but some variation of the design might work,,, they are volume restricted as the pressure gets higher.

Another possible solution might be a solid billet drilled to intersect at 90 degrees or the angle required internally of the billet, this would eliminate bending but require a welded or flange and compression seal and interrupt laminar flow,,, these flanged 90's are commercially available and used in oilfield choke and kill lines.

I almost forgot to ask "what pipe joining" design is being used presently ?
The design method used would suggest it's own solution,,, and minimize stupid.

justashooter
April 18, 2017, 14:44
Try Greiner Industries in mt joy pa. ask for Bruce Stine. He is meticulous and their forming shop is by far the best on the east coast.

bending tubing is tricky.
thin wall can be filled with water and frozen before bending to prevent collapse, or filled with sand and end capped. this job sounds like a special forming die will be required. I have seen 48X372# wide flange rolled beams roll formed at Greiner, the hard way. they can do just about anything.
http://www.greinerindustries.com/