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Posted by outofstepper on April 29, 2008, 4:12 am
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Greets all & good morning.
would like to preface this by saying I'm not a full-time
weldor. Used to do alot more but now I like to pick
and choose my work -- 99% of the time its TIG --
typically Al & SS structural -- not a pipe weldor!
close friend of mine is a contract weldor and asked
me to lend a hand running tig root pass on a lot
contract (he'd follow up behind with a 7018 cap).
welding 3" sch 80 pipe on a bench. These are
elbow assemblies made of 1 elbow, an 8" extension
on each end, and 2 flanges. I only needed to weld
the elbow/extension.. not the flange.
I didn't need to bring anything except gloves and a
helmet -- everything else would be provided.
(They supplied an old scratch-start aircooled torch
kit wired to the oldest DC machine I've ever seen --
but thats a different story)
anyway, I found 300 of these assemblies already
"preped" and ready to weld. each was spot welded
and they used 3/8" rounds (with 3/4" mig
beads!) in four places around each joint -- every
90 degrees to set the gap -- which meant I could
only weld 'round the joint about 1.5" before I'd have
to stop and grind that 3/8 round out and fix the bevel
that the mig "tack" filled.
man this is getting long winded -- sorry.
bottom line is: is a 3/8" gap pure madness on 3" pipe?
i started welding these flat on the table (1G position)
but couldn't get a consistent profile on the inside
penetration. (all they had was 3/32" filler and 3/32"
tungstens).
Next, I flipped them up on their flanges and welded
each joint in a 2G position and I got much more
consistent results with a great profile on the inside.
One satisfactory completed piece, with only the root
tig weld, on two joints (less than 20" of weld bead)
took me exactly 45 mins (including the grind time).
Q: is it my lack of experience with pipe welding? is
a 3/8" gap on this size pipe normal? in the end the
welds looked good, inside and out -- got a cupwalking
ripple pattern even though I had to float it (don't know
how to walk) because of the CHASM I had to cross.
there were no prints / specs / etc to follow.. just
"here's your pile of stuff -- weld it up for us"
thanks for stick'n through this. :)
Tony
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Posted by Bruce in Bangkok on April 29, 2008, 5:50 am
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On Tue, 29 Apr 2008 01:12:48 -0700 (PDT), outofstepper
>Greets all & good morning.
>would like to preface this by saying I'm not a full-time
>weldor. Used to do alot more but now I like to pick
>and choose my work -- 99% of the time its TIG --
>typically Al & SS structural -- not a pipe weldor!
>
>close friend of mine is a contract weldor and asked
>me to lend a hand running tig root pass on a lot
>contract (he'd follow up behind with a 7018 cap).
>
>welding 3" sch 80 pipe on a bench. These are
>elbow assemblies made of 1 elbow, an 8" extension
>on each end, and 2 flanges. I only needed to weld
>the elbow/extension.. not the flange.
>
>I didn't need to bring anything except gloves and a
>helmet -- everything else would be provided.
>
>(They supplied an old scratch-start aircooled torch
>kit wired to the oldest DC machine I've ever seen --
>but thats a different story)
>
>anyway, I found 300 of these assemblies already
>"preped" and ready to weld. each was spot welded
>and they used 3/8" rounds (with 3/4" mig
>beads!) in four places around each joint -- every
>90 degrees to set the gap -- which meant I could
>only weld 'round the joint about 1.5" before I'd have
>to stop and grind that 3/8 round out and fix the bevel
>that the mig "tack" filled.
>
>man this is getting long winded -- sorry.
>
>bottom line is: is a 3/8" gap pure madness on 3" pipe?
>
>i started welding these flat on the table (1G position)
>but couldn't get a consistent profile on the inside
>penetration. (all they had was 3/32" filler and 3/32"
>tungstens).
>
>Next, I flipped them up on their flanges and welded
>each joint in a 2G position and I got much more
>consistent results with a great profile on the inside.
>
>One satisfactory completed piece, with only the root
>tig weld, on two joints (less than 20" of weld bead)
>took me exactly 45 mins (including the grind time).
>
>Q: is it my lack of experience with pipe welding? is
>a 3/8" gap on this size pipe normal? in the end the
>welds looked good, inside and out -- got a cupwalking
>ripple pattern even though I had to float it (don't know
>how to walk) because of the CHASM I had to cross.
>
>there were no prints / specs / etc to follow.. just
>"here's your pile of stuff -- weld it up for us"
>
>thanks for stick'n through this. :)
>Tony
We laid a bunch of 3" sch 80 lines, 100% x ray, in a small field and
the pipe fitters gaped the joints about 1/8" (1/8" 6010 root and 7018
for hot and cover passes). We didn't use a bent rod, just the "that
looks about right" gage system. I would think that TIG would be the
same, or even less.
Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)
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Posted by outofstepper on April 29, 2008, 7:47 am
Please log in for more thread options Thanks Bruce.
These were all beveled by the way -- I was told that
ahead of time and thats what I found -- 60 degree with
maybe an 1/8" root face -- a bit hit and miss, I think
these were ground using a jig and angle grinder.
I expected to find no gap at all..
-Tony
>
> We laid a bunch of 3" sch 80 lines, 100% x ray, in a small field and
> the pipe fitters gaped the joints about 1/8" (1/8" 6010 root and 7018
> for hot and cover passes). We didn't use a bent rod, just the "that
> looks about right" gage system. I would think that TIG would be the
> same, or even less.
>
> Bruce-in-Bangkok
> (correct Address is bpaige125atgmaildotcom)
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Posted by Bruce in Bangkok on April 29, 2008, 8:21 am
Please log in for more thread options On Tue, 29 Apr 2008 04:47:49 -0700 (PDT), outofstepper
>Thanks Bruce.
>
>These were all beveled by the way -- I was told that
>ahead of time and thats what I found -- 60 degree with
>maybe an 1/8" root face -- a bit hit and miss, I think
>these were ground using a jig and angle grinder.
>
>I expected to find no gap at all..
>
>-Tony
I thought you were saying the joints had a 3/8" gap.(which I thought a
lot). The pipe we were welding was beveled (generally with an 8"
grinder) clamped and down hand welded. I will say that the welder and
the pipe fitter were part of the three man team so if the gap "wasn't
right" it got changed and I'm sure that they varied from crew to crew
but the specs (as far as I can remember) called for 60 degree vee with
1/8" root -- but it was quite a few years ago.
From what you say, you must be spending all your time getting a good
looking bead. Is it hourly pay or piece work?
>>
>> We laid a bunch of 3" sch 80 lines, 100% x ray, in a small field and
>> the pipe fitters gaped the joints about 1/8" (1/8" 6010 root and 7018
>> for hot and cover passes). We didn't use a bent rod, just the "that
>> looks about right" gage system. I would think that TIG would be the
>> same, or even less.
>>
>> Bruce-in-Bangkok
>> (correct Address is bpaige125atgmaildotcom)
Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)
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Posted by SteveB on April 29, 2008, 12:56 pm
Please log in for more thread options IIRC, the root opening should be the size of the filler rod as a very
general rule of thumb. It is difficult when you have to pick up the next
step from someone who obviously doesn't know what you do or how you do it.
Since you got in on this late, and didn't get to go to the planning meeting,
that makes it bad. If it's all beveled, a 3/8" root sounds excessive.
What's your responsibility in this? If one of these leaks, is it going to
be blamed on bad joint design, an excessive root, or YOU? Sounds like you
got a bad design, questionable equipment, and not a lot of instructions.
So much for "friends".
Steve
> Greets all & good morning.
> would like to preface this by saying I'm not a full-time
> weldor. Used to do alot more but now I like to pick
> and choose my work -- 99% of the time its TIG --
> typically Al & SS structural -- not a pipe weldor!
>
> close friend of mine is a contract weldor and asked
> me to lend a hand running tig root pass on a lot
> contract (he'd follow up behind with a 7018 cap).
>
> welding 3" sch 80 pipe on a bench. These are
> elbow assemblies made of 1 elbow, an 8" extension
> on each end, and 2 flanges. I only needed to weld
> the elbow/extension.. not the flange.
>
> I didn't need to bring anything except gloves and a
> helmet -- everything else would be provided.
>
> (They supplied an old scratch-start aircooled torch
> kit wired to the oldest DC machine I've ever seen --
> but thats a different story)
>
> anyway, I found 300 of these assemblies already
> "preped" and ready to weld. each was spot welded
> and they used 3/8" rounds (with 3/4" mig
> beads!) in four places around each joint -- every
> 90 degrees to set the gap -- which meant I could
> only weld 'round the joint about 1.5" before I'd have
> to stop and grind that 3/8 round out and fix the bevel
> that the mig "tack" filled.
>
> man this is getting long winded -- sorry.
>
> bottom line is: is a 3/8" gap pure madness on 3" pipe?
>
> i started welding these flat on the table (1G position)
> but couldn't get a consistent profile on the inside
> penetration. (all they had was 3/32" filler and 3/32"
> tungstens).
>
> Next, I flipped them up on their flanges and welded
> each joint in a 2G position and I got much more
> consistent results with a great profile on the inside.
>
> One satisfactory completed piece, with only the root
> tig weld, on two joints (less than 20" of weld bead)
> took me exactly 45 mins (including the grind time).
>
> Q: is it my lack of experience with pipe welding? is
> a 3/8" gap on this size pipe normal? in the end the
> welds looked good, inside and out -- got a cupwalking
> ripple pattern even though I had to float it (don't know
> how to walk) because of the CHASM I had to cross.
>
> there were no prints / specs / etc to follow.. just
> "here's your pile of stuff -- weld it up for us"
>
> thanks for stick'n through this. :)
> Tony
>
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| Similar Threads | Posted | | Re: Now 6010 root (happy 7018 fill)- what rod sizes and types | April 10, 2006, 10:51 am |
| Re: Now 6010 root (happy 7018 fill)- what rod sizes and types | April 10, 2006, 10:56 am |
| Re: Now 6010 root (happy 7018 fill)- what rod sizes and types | April 10, 2006, 2:13 pm |
| Re: Now 6010 root (happy 7018 fill)- what rod sizes and types | April 12, 2006, 1:53 am |
| Re: Now 6010 root (happy 7018 fill)- what rod sizes and types | April 15, 2006, 10:17 pm |
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>would like to preface this by saying I'm not a full-time
>weldor. Used to do alot more but now I like to pick
>and choose my work -- 99% of the time its TIG --
>typically Al & SS structural -- not a pipe weldor!
>
>close friend of mine is a contract weldor and asked
>me to lend a hand running tig root pass on a lot
>contract (he'd follow up behind with a 7018 cap).
>
>welding 3" sch 80 pipe on a bench. These are
>elbow assemblies made of 1 elbow, an 8" extension
>on each end, and 2 flanges. I only needed to weld
>the elbow/extension.. not the flange.
>
>I didn't need to bring anything except gloves and a
>helmet -- everything else would be provided.
>
>(They supplied an old scratch-start aircooled torch
>kit wired to the oldest DC machine I've ever seen --
>but thats a different story)
>
>anyway, I found 300 of these assemblies already
>"preped" and ready to weld. each was spot welded
>and they used 3/8" rounds (with 3/4" mig
>beads!) in four places around each joint -- every
>90 degrees to set the gap -- which meant I could
>only weld 'round the joint about 1.5" before I'd have
>to stop and grind that 3/8 round out and fix the bevel
>that the mig "tack" filled.
>
>man this is getting long winded -- sorry.
>
>bottom line is: is a 3/8" gap pure madness on 3" pipe?
>
>i started welding these flat on the table (1G position)
>but couldn't get a consistent profile on the inside
>penetration. (all they had was 3/32" filler and 3/32"
>tungstens).
>
>Next, I flipped them up on their flanges and welded
>each joint in a 2G position and I got much more
>consistent results with a great profile on the inside.
>
>One satisfactory completed piece, with only the root
>tig weld, on two joints (less than 20" of weld bead)
>took me exactly 45 mins (including the grind time).
>
>Q: is it my lack of experience with pipe welding? is
>a 3/8" gap on this size pipe normal? in the end the
>welds looked good, inside and out -- got a cupwalking
>ripple pattern even though I had to float it (don't know
>how to walk) because of the CHASM I had to cross.
>
>there were no prints / specs / etc to follow.. just
>"here's your pile of stuff -- weld it up for us"
>
>thanks for stick'n through this. :)
>Tony