Nozzle Cutout in Rolled Shell of Vessel with Cladding

What could work here is a multi-axis milling machine mounted on an arm with a magnetic or other mechanical base that would attach to the vessel shell. I don't know if anyone makes such a device, but I would suspect so. Next questions: How to find it? What search terms?

Thanks Tornado - how about this one? I'll inquire Monday about other features of this machine, such as size (we may have a height problem under the hook), etc. I'm not exactly sure how it would mount (Mag, mechanical?) by the information given.

http://www.ltsenergy.com/product.php?c=5&sc=44&p=46

Not being an engineer, I just didn't know which way to go with it. If this one is feasible, it beats the band-saw apparatus I was thinking about. If anyone has other ideas, I'm all ears. We have to build two of each of these scrubbers here before long.

Ken

Wow.....You need to purchase gaint expensive equipment, purchased to cut precise holes in massive heads.

Of course the client wants it right away.

I am guessing here, but.....is this a newly formed company and is this your first major job of this size ?

Do you have many MBAs in your newly formed company, and are you looking to hire a mechanical engineer and assign him this task ?

Where are you located ?

They have added a few people for this project already - might hire a few more welders at some point before material is due to arrive. We are in Southeast USA

Kenholl.... I work for a company who does work of this type.. .check www.orbitaltool.com for a listing of our capabilities. We should be able to help you.

we do lot of power plant work on turbine shells etc Brian Duffy

Thanks, I have attempted to contact. I saw no email addresses on the site provided, so I filled in the form and asked for someone in sales to contact via email.

The way to do this is by using a hand-held plasma cutting torch. Have a skilled fitter layout and punch-mark the hole size on the stainless side and cut from the stainless side. Use the torch to create the weld bevels that you desire. Finish the hole using a hand grinder to remove all of the burnt slag and to get to sound metal.

Thanks Laurence - I wasn't aware that Plasma could cut through that thickness. The smaller vessels will be 2.25"- 2.5" of carbon base metal, with 3/16" SS clad. The larger vessels will be about 3.5" base carbon with same cladding.

If you haven't done this before, I would recomment practicing on some scrap of that thickness before using on the vessel.

You don't have to go to all that trouble. I have done this a million tmes. I used to work for Horton CBI as a "burner" before becoming a Mechanical Engineer now working for GM. Regular Oxy Acetalyne equipment will do if you cut from the mild steel side. You have enough thickness of mild steel to blow through the SS cladding. The trick is to use the correct and constant speed and when cutting it. you have to go straight through though. No angle or the ox stream will be deflected. The other option is to grind the cladding off and burn using just oxy/acet. Hope that helps.

If you haven't solved this problem yet, this is what you need:

http://www.circlewelders.com/prod-circleburn.shtml

We just got one of these (from this company) in our shop. It will cut 3-in steel like butter with oxyfuel. You can use plasma instead or anything really; the rig is basically designed to hold the head of whatever cutting implement you choose. It's completely automated once you get it set up and going. It will cut any bevel angle you like. The neatest thing in my opinion (besides cutting orders of magnitude faster than a person) is that it can cut perfect nozzle holes through the SIDES of vessels. You just set it up properly and it will follow the outside of the vessel and the cut the proper hole with bevel. The bevels are smooth, so they require almost no preparation before welding.

And, no, I do not work for this company. I'm a chemical engineer. However, I was pretty blown away watching 3-inch-thick, perfectly-beveled holes be cut in a matter of minutes. I hope this will help.

Thanks for your reply. That is the machine we'll be getting - I already have the quotes on it, and the Mfg has agreed to modify it for larger nozzle diameters. We'll probably remove the cladding from the diameter of the cut so the SS/Ni won't even be a factor.

Ken