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Large 2m dia pipe welding?

Posted: Fri Apr 17, 2020 9:47 am
by Trevor
Hey guys.. hoping people with pipe experience can pipe up. First off a bit about myself.. Been stick welding heavy gauge mild steel for 35 years. By heavy I mean 1" thick or heavier. I have about 2 years experience in welding pressure pipe.

Recently the owner has thrown a big job in my lap and I came here to gather info so I can quote this job.
I have to cut what is called a joint off the end of a 2m dia pipe and reattach another type of joint. The wall thickness is 2"
Pictures will follow.

I would like to know what the travel speed of mig and stick is. How many inches can be laid down in one minute. Is there somewhere I can reference this? We use .035 hardwire and stick. We have only one Mig machine and one diesel 300 stick welder 7018. Would it be a problem if one type was to weld over the other?

My plan is to round the pipe and joint. braces will be added and not removed till completed. I was thinking of beveling a Y joint on the outside and inside of the Joint pipe being added, and welding dogs on to keep it aligned during welding. Normally these pipes are welded by robot.

Would love to hear your opinions
uploading pics soon

Re: Large 2m dia pipe welding?

Posted: Sat Apr 18, 2020 8:58 am
by Poland308
Depends on the bevel. Something that thick will likely call out a J prep. Or some other machined bevel. You might have a day or two even with a Wachs pipe beveling machine and a couple of experienced operators. Weld time will vary a lot between stick or mig. Especially if it’s something you can get in a positioner or not. Machine time plus stick weld in position I’m guessing would be around 60 man hours.

Re: Large 2m dia pipe welding?

Posted: Sat Apr 18, 2020 6:40 pm
by Trevor
Well.. some more info came my way from the supplier of the joint. Turns out that there is a 3/4" Y bevel on the outside and a 3/8 bevel on the inside. So its not 100% weld.. maybe 50% whew! I quoted the welding alone at 8 hrs given a travel speed of 12" per min.if it were to be welded by robot. Of course I don't have a robot so 16hrs is more realistic. I suspect it will take me almost two days to cut of the original joint and tack the new one. Im pretty good with the torch so I would say about 4 hrs to cut and bevel. 4 hrs more to align and tack.+++

So then I gave the owner this ruff quote and he said "Good! There's now FIVE to do!" :shock: :D

Re: Large 2m dia pipe welding?

Posted: Sun Apr 19, 2020 7:58 am
by LtBadd
Trevor wrote: So then I gave the owner this ruff quote and he said "Good! There's now FIVE to do!" :shock: :D
Gotta like that!
Post some pics of this project as you work on it if you don't mind.

Re: Large 2m dia pipe welding?

Posted: Tue Apr 28, 2020 12:27 pm
by BugHunter
Trevor wrote:So then I gave the owner this ruff quote and he said "Good! There's now FIVE to do!" :shock: :D
This always scares me when this is the response I get to a quote. LOL.

Re: Large 2m dia pipe welding?

Posted: Tue May 12, 2020 12:34 pm
by Trevor
Welp...5 joints turned into 5 joints and 5 clamps. Oh and let's shorten the deadline by one week.

Many pictures to follow.