Orbital TIG

[codearc]

Anyone had much to do with large diameter Stainless steel tube im in the process of sourcing a machine for tubes from 250mm od to 608mm od i have had alot of experience with small orbital machines but there is so much good and bad about the larger machines so far i have been quoted by ESAB TPS FRONIUS and AMI the Fronius is the cheapest option but they dont have much in the uk infact i think they have sold about 4 machines in the UK training isnt great as they will send a guy to Austria for a week then send him to us to train our guys for a week (i really dont think he is gonna learn as that much in a week) i feel we need someone who knows this machine inside out.ESAB are prepard to send me to Sweden to test the machine and see the whole set up process which i do find brave of them confidence with these guys .AMI have sold alot of these machine in the UK have alot of stock on the shelf and a mind full of information and experience but they are the most expensive money is an issue here does anyone know of another option to be quite frank all our wourk is large bore thin wall stainless tube we dont need bells and braces we need simple and reliable is there such a machine under 50k?

[pulser]

Yep, the prices of these things are totally outrageous!
What is the maximum thickness you'll be welding?
Do you require wire feed?
How much space is available for the weld head, do you need a low profile compact head?

Here are a few other orbital equipment manufacturers.
http://www.magnatech-lp.com/
http://www2.liburdi.com/
http://www.weldlogic.com/
http://www.goencompass.com/tube_welding.html
http://www.ap-automation.com/
http://www.astroarc.com/

Used, maybe if you're lucky.
http://www.weldplus.com/index.htm

[zapster]

i've welded stainless tubes from 1" to 30"

no big deal...

...zap!

[Engloid]

I have used the Liburdi machine. They're really easy to program. I only did as large as 4" tube though.

I also used the AMI machine. Its a bit harder and more time consuming to program, but does have more features and abilities.

Why not weld it all by hand and save all the money?

[pulser]

Zap, the man asked about orbital welding equipment, not how far out in space you ego is. You've got almost 2000 posts since you joined in January, and that has to be a record, but do you feel that a one liner response such as this is really beneficial to anyone. Got to admit though, it's entertaining .

There is probably a good reason why Codearc is looking for a mechanized weld system. First off, there is only one Zapster, and he doesn't live in the UK.

Secondly, it likely a critical application such as pharmaceutical, semiconductor, biochemical, nuclear, or maybe brewing, that requires the very finest smooth ID penetration, minimal HAZ, best corrosion resistance, etc. And there's probably a bunch of these welds and they need them all to be of utmost identical quality. Maybe access to the tubes is too tight to get in there with your mirror to weld around the damn thing. There's a bunch of reasons why companies spend boat loads of money on machine welding, weld techs and engineers.

I hope to hear more about Codearc's welding project.

[Shane@profab]

I did some research into this a year or two ago, the company that I thought would be most helpfull was orbimatic - the only reason why i say so is that they published a free orb' tig guide on the net. I always respect and am gratefull to people that freely make such literature available for my continued education and would always try and support them - am I starting to sound like I have shares in the business???

Anyway, orbimatic is in the UK so that could help.

I have a ESAB torch (x2) and controller hooked up to an ESS power for doing this kind of work, THe max I can weld is 180 or 200 OD (cant recall). As a rule, this kind of technology is very expensive, I think not so much for the electronics but more so for the limited numbers in the market.
Localy (in RSA) a new company is selling orbital welding kit at a fraction of the ESAB type stuff, I think its eastern (chinese/korean or the like), but for the love of me I kind remember the name, something like iaxa

I would be keen to know which context you intend using the machine in - shop or site, what schedule pipe etc
As a relatively inexperienced welding bloke, I would have thought that orbital Tig on large diameter with thicker walls would be slow and uneconomical meaning that you would only use it in super crticical applications (pharm,food and bev) and then those pipes are not normally that big.
Would an automated mid machine using say flux coreed wire not be more suitable?

[Engloid]

Would an automated mid machine using say flux coreed wire not be more suitable?

Mig welding on full penetration pipe welds (food service or pharmaceutical) would be like walking a tight rope with a 300lb backpack on. It would just be way too difficult to perfect, and the cost and frequency of repairs would be high.


It's hard for a human to compete with the consistency of an automated tig machine, IF you can get the fitups needed.

The weld below was 4", and welded with the Liburdi machine. This machine does not use any filler metal.

A weld like this will be acceptable in pharmaceutical applications.

The AMI machine I used did use filler. It was really amazing, the things it will do. It's about twice the money though.

If you use an orbital machine, be prepared to get PERFECT fitups. You cannot have even the light of day showing between the two. ...well, maybe just a little bit. If you are making cuts with a portable band saw, be prepared for a lot of grinding to get a really great fitup. This is the advantage to sometimes using a person to weld, as they can adapt to inconsistent fitups better than an automated welder can.

[zapster]

Zap, the man asked about orbital welding equipment, not how far out in space you ego is. You've got almost 2000 posts since you joined in January, and that has to be a record, but do you feel that a one liner response such as this is really beneficial to anyone. Got to admit though, it's entertaining .

There is probably a good reason why Codearc is looking for a mechanized weld system. First off, there is only one Zapster, and he doesn't live in the UK. (quote)





yeah...whatever
but i'm the first one to actually help anyone that needed it..

besides i have nothing to prove..

the only person you have to better than is yourself..

...zap!

[codearc]

The reason for going over to automatic welding is purely the volume of work we have it has been stated that the type of machine we are looking for is 3 times more productive than manual welding and seeing that a reasonable TIG welder costs £40k + a year not only this we can use less skilled people to operate it once the program is set it doesnt winge about travel time overtime nore does it stop for cig breaks coffe breaks tea breaks and if there is no work it sits on a shelf not costing a penny and yes ultimately the quality is repeatable everytime

[pulser]

So do you need orbital? Now it sounds like this is in a shop where you could rotate the assembly and weld with a fixed torch? If that's the case, the solution is alot easier and less expensive than an orbital system.

How about some more info, I'm curious.
Do you have to weld with the pipe in a fixed position?
What is the maximum thickness you'll be welding?
Do you require wire feed?
How much space is available for the weld head, do you need a low profile compact head?

[codearc]

Some very helpfull coments here the type if pipe we are using is thin wall from 2.5mm to 4mm we are hoping to weld these joints in 1 pass we have just completed a 1km pipline 500mm we welded 2 lengths together and flanged the ends as it had to be installed under water in a river the flanges are just collars that are similar to weld necks anyway all in all its 3 but welds to a 12m length we used to our Fronius digital pulsed synurgic machine on rotators as they were just straight lengths we had some amasing result sand perfect penetration and a nice looking bead it only takes 3.5 mins to comlete each weld with setting up etc 1 skilled welder and a labourer could weld 9 butts a day all purged and cleand (used quik purge bladders) if anyone can tell me how to post pictures i will put them up

[codearc]

So do you need orbital? Now it sounds like this is in a shop where you could rotate the assembly and weld with a fixed torch? If that's the case, the solution is alot easier and less expensive than an orbital system.

How about some more info, I'm curious.
Do you have to weld with the pipe in a fixed position?
What is the maximum thickness you'll be welding?
Do you require wire feed?
How much space is available for the weld head, do you need a low profile compact head?

we need to be able to weld in positon as the next job is complicated with bends and tees etc
yes we will need a wire feed
the esab machine we are looking at only needs 78mm

We will be using this machine mainly at our factory but will be welding on site but in workshop conditions

[pulser]

To post photos scroll down below Reply to Thread to Additional Options, Attach Files, Manage Attachments, Upload File From Your Computer, etc.

If your file size is too large, you can upload the photos to http://www.photobucket.com/
and then copy the link to the photo to you posting, such as the following:
http://i94.photobucket.com/albums/l1...ds/PGTAWOD.jpg

Good luck with your orbital system.

[codearc]

got wet putting this in

[codearc]

http://s128.photobucket.com/albums/p186/codearc/

[pulser]

yep,
nice job!
All that beautiful welding gives me wet panties too!

[Engloid]

The reason for going over to automatic welding is purely the volume of work we have it has been stated that the type of machine we are looking for is 3 times more productive than manual welding

Just remember that you WILL have to spend more time to prep for the welds than you would if you had a human welder. I would like to see this machine weld 3 joints to my 1. Was it a salesman that gave you this figure?

it doesnt winge about travel time overtime nore does it stop for cig breaks coffe breaks tea breaks

It will stop every time your operator does.

So do you need orbital? Now it sounds like this is in a shop where you could rotate the assembly and weld with a fixed torch? If that's the case, the solution is alot easier and less expensive than an orbital system.

It can often be hard to do that because many motorized rollers won't roll smoothly enough. You also have problems with anything that has elbows in it.

On the 4mm wall thickness....good luck welding it in one pass. The problems you will encounter:
1) You will have to bevel the pipe to get penetration.
2) How will you get the bevel and gap consistent enough for an automated welder to do it?
3) If you do not bevel, you still will need a really consistent fit. In that case, you will run so hot to get penetration that you will have problems with the weld sagging or dripping out and blowing a hole.

You will be needing to go to an argon/hydrogen mixed gas also. 95/5 mix works well.

I really think you will find that a human welder, and a good one, will do better for your application. DO NOT BUY ANY MACHINE UNTIL YOU SEE IT PERFORM THE EXACT TASK YOU WANT IT TO!!!!!!! Many of these companies will tell you it will do what you want, but after spending $50-100k spent, you can never make it work out and are stuck with the machine.

Nice pic on the bike, btw. I ride a gsxr 1000. A recent trackday wipeout has slowed me a bit though.

[codearc]

we have a mandril type tool that hold an angle grinder the tube ends are perfectly square and we will prep/bevel the end of the tube with a 2.5mm landing edge 2.5mm is the maximum we can penetrate i am thinking that with pulse and the right gas we should be able to fuse the root of the weld and fill the cap we only need a fused root 0.5mm is way more that enough penetration

As for the bike im off it at the moment i had a nice off this time last year brocken ribs and im just waiting for an op on my thumb (cant hold the torch or fead the wire any more)

[zapster]

Nice pic on the bike, btw. I ride a gsxr 1000. A recent trackday wipeout has slowed me a bit though.(quote)


ouch!!

...zap!

[zapster]

As for the bike im off it at the moment i had a nice off this time last year brocken ribs and im just waiting for an op on my thumb (cant hold the torch or fead the wire any more) (quote)



double ouch!!

...zap!

[Engloid]

we have a mandril type tool that hold an angle grinder the tube ends are perfectly square and we will prep/bevel the end of the tube with a 2.5mm landing edge 2.5mm is the maximum we can penetrate i am thinking that with pulse and the right gas we should be able to fuse the root of the weld and fill the cap we only need a fused root 0.5mm is way more that enough penetration

You may be able to make it work then. I would reccomend trying it with argon first, due to cost. If you have penetration issues, swap to the 95Argon/5Hydrogen.

The hydrogen mix will get a deeper penetration, as well as wider. This helps to ensure that you do fuse the actual point that the two pieces of pipe meet.

As for the bike im off it at the moment i had a nice off this time last year brocken ribs and im just waiting for an op on my thumb (cant hold the torch or fead the wire any more)

So that we don't hijack this thread topic, I'll go to the off-topic section and post up some pics of my bike wreck, and my day of riding. Check it out.

[pulser]

Here's a link to one of the major companies making a variety of tube/pipe cutoff and end prep machines. This is how you ensure the perfect fit-up required for orbital welding. http://www.tritool.com/

I guess your company would need a lot of this type of work to justify purchasing orbital prep and weld equipment. The fact that once you get setup it is quite easily produce amazingly consistent welds has to be a large consideration.

Engloid has several good points on the difficulty of proper joint prep, fit-up, and single pass penetration limitations.

I know that 95/5 Ar/H absolutely increases the power input to the weld at a given current. The reason for this is that the two atoms comprising the hydrogen molecule become dissociated in the arc plasma, absorbing a large amount of energy to break their bonds, and this energy is then very efficiently transfered to the weld puddle when the atoms recombine there. The net effect is about a 25% increase in the thermal conductivity of the Ar/H over straight Ar. 95/5 is quite common in precision autogeneous TIG of small stainless steel components. Austenitic stainless steels and other austenitic nickel alloys can handle some level of hydrogen without porosity problems, or embrittlement as in hardenable steels. However, I believe I read of some cautions in using 95/5 for multi-pass welds, not sure what issues may arise, maybe porosity. Maybe ok to help with root penetration, then switch to Ar for fill.

Also, Codearc, are you aware of the weld penetration variation created by differing sulfur content of stainless steels? It can be a huge problem in orbital welding if you've never seen it before. The phenomena is referred to Marangoni flow or thermocapillarity, and refers to the temperature and surface tension driven flow within the weld pool that can have very dramatic effects on weld depth and width. A very clean steel with sulfur of only 20 ppm will have an outward flow that make the weld wide and shallow. As you crank up the current to increase penetration, the flow is simply driven stronger and the weld gets wider and wider with little increase in depth. However, the converse in true for the high sulfur material, with 150 ppm or more, the flow is inward and downward, which effectively transfers heat from the arc downward in the pool, creating a deep/narrow weld. Autogeneous welding up to around 1/8" thickness may be possible with a high sulfur heat, but only maybe 1/16" max with a low sulfur heat.
Here is one related article discussing thermocapillarity.
http://files.aws.org/wj/supplement/Pierce/ARTICLE3.pdf

By the way, I worked for Dimetrics back in the 80's. After several transitions, they are now Liburdi Dimetrics. I've got a bit time in on small autogeneous tube heads, the Gold Track & wire feed heads, and the "Metal Beam" orbital pulsed GMAW pipe welding.

[Engloid]

Ive used the 95/5 for multi pass welds, and never had any problems. I did notice that if I was on some really heavy material and put a lot of the foot pedal into it, it would occasionally pop out like tigg'ing over galvanized will do. It would not do this often, and only if I pressed the pedal much farther than necessary, just messing around.

[pulser]

Thanks for the 95/5 feedback. Just curious if these welds were inspected for voids by any means such as radiography or ultrsonic?
Thanks

[Engloid]

Nope...but you know how you can pretty much know what's happening in a weld as you're welding it.

I suspect that when I hammered down a lot of amperage that it made the puddle very deep, and actually blew gas into the puddle, like a straw into a glass of milk..and then it expanded and blew out. I don't think it was a matter of it putting the gas in there all the time.