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noel30
06-02-2011, 05:04 AM
Can I do SMAW welding in 4 inch pipe schedule 40? I try to do weld 6G pipe welding using 6010 for root pass in 4 inch pipe schedule 40 but the result is really bad, when I try to increase the current I can see that the bevel pipe is melted and leave a hole, when I decrease a current the 6010 rod is stick in pipe especially from overhead position welding.

What should I do? Thanks all.

welds4d
06-02-2011, 08:18 AM
Sure, you can SMAW weld 4" pipe. You don't say what kind of machine, settings, pipe end prep, rod size, etc. that you're using....

noel30
06-02-2011, 09:49 AM
Im using 2.5 mm 6010, and my machine is miller I just dont know the amperage settings of machine because the meter is not working so I'm looking only in the fire of the rod to determine the current. I bevel the pipe using lathe machine 30 degree in both pipe total of 60 degree grove.

gordfraser
06-02-2011, 01:57 PM
Did you try a pipe with the groove in the horizontal position?
Then the vertical.
Then the 6g

What size of gap and land do you have?

slim83
06-02-2011, 02:18 PM
Try a heavier landing and a 1/16 gap. You are gonna have to move fast and steady

noel30
06-02-2011, 03:07 PM
The same size of electrode is 2.5mm the land and gap, I use only 2.5 mm 6010 because I think if I use more bigger rod and increase the land and gap I need to compensate more current and the pipe i use for practice is 4 inch schedule 40, The wall is thin so I use a 2.5mm rod only same size on land and gap.

noel30
06-02-2011, 03:10 PM
how many amperage for 6010 2.5mm welding rod, I practicing a Pipe welding in 4 inch steel pipe schedule 40 using miller arc welding machine, but every time I weld for root pass the electrode stick on pipe if I increase the current I can see that the bevel of pipe is melted and leave a hole if I decrease the rod stick. Any advice thanks all

noel30
06-02-2011, 03:16 PM
Is it alright to have 1/16 or 3.2 mm land even my pipe schedule is only 40 and do i need to use welding rod size 1/16 also. I don't know if this correct, Is it true that if I use 2.5 mm rod should supposed to be my land and gap should also 2.5 mm and if I use 3.2 mm rod also the land and gap should same of the rod size,correct me if I'm wrong thanks all for advice.

CEP
06-02-2011, 03:41 PM
I have the most problems with 2 inch sch 40 in the 5-G position uphill, (Most likely it's just a mental block):laugh:. 6-G is no problem, sch 80 is no problem either 5-G or 6-G, and I only use 1/8 inch rod for the root.
You have to find what joint prep works best for you.
I like a 1/16 inch land, and 1/16 inch gap, around 60 to 65-amps, for both 5-G or 6-G up hill root.

noel30
06-02-2011, 04:09 PM
That is nice welding. In schedule 80 pipe I think is not to much problem cause the wall is thicker so the penetration can long last, but in schedule 40 thin wall too bad for me I can see the bevel is melted. What should be the standard land and gap for pipe welding in 4 inch pipe in schedule 40 if I will use a 6010 2.5 mm welding rod for root pass. Should be the same also of my welding rod size the land and gap i will apply in pipe.thanks.

CEP
06-02-2011, 04:18 PM
According to my book, 2 inch sch 80 pipe is .218. 4 inch sch 40 is .237.

noel30
06-02-2011, 04:25 PM
I see I will try it next time to have gap same as that. I think I commit mistake in land and gap, I just apply same rod size I use for the land and gap of schedule 40 which is 2.5mm. Thanks for that.

CEP
06-02-2011, 04:32 PM
I think you'll find, I know I do, different brands penetrate more than others. With Hobart's 335A 6011 I go with just about 3/32 inch land, but still 1/16 inch gap.

noel30
06-02-2011, 05:00 PM
I will try next time to have 1/8 root opening and try to use 1/8 6010 welding rod for root pass in 4 inch schedule 40 pipe. Do u think it is possible to weld it.

MadMax31
06-02-2011, 06:22 PM
Possible? Yup, on our current boiler job, Ive welded 2" sch 40,80. 4,5,6" sch 40,80 and 8" sch 80.

All with 1/8 6010, 3/32 7018.

Smaller pipe you need to move your ***, you cant futz around in any one position, theres not alot of meat to soak up the heat, so running hotter is a bad idea. You have to pay more attention to rod angles, and just how hot that joint is getting,

CEP
06-02-2011, 06:26 PM
I will try next time to have 1/8 root opening and try to use 1/8 6010 welding rod for root pass in 4 inch schedule 40 pipe. Do u think it is possible to weld it.

I couldn't handle that big of a gap! I'm not a pipe welder, just a lowly old structural hand.:(

noel30
06-02-2011, 07:46 PM
Yes, making bigger the rod means need to increase current and more tendency to melt the pipe easily, By the way, if I will apply a 1/8 root opening, how big the land i will apply in pipe should also big as 1/8? This what makes me confused what the proper root opening and land should apply.

gordfraser
06-02-2011, 09:01 PM
i do:
1/8" 6010 @ 63 amps (lower end of rod/amp range)
37.5 bevel, 1/8 land, 3/32 gap.
whip it out and push it in h, hold for a couple of moments the start again.
point rod to center of pipe in all positions.

keyhole opens up whip quicker

the rest is up to the way you weld, but that should get you going

noel30
06-03-2011, 03:49 AM
37.5 bevel this can be apply in 4 inch schedule 40 steel pipe? I apply only 30 bevel using lathe machine and protractor. I see so it is not necessary that the rod size I will use will be the the same size of gap and land also. It can be differ also.

weldbead
06-03-2011, 05:37 AM
there are many combinations you can strike of gap and land. thicker land will need a little more heat to burn through..try different things, post fotos..

monkers
06-03-2011, 06:24 AM
Is there a page or link that will show me and explain all the terms you guys are using? I will probably never weld pipe, but I would like to know what you`re talking about haha.... Root opening, land , gap etc?? I understand the pipes are both beveled, then you leave a space between them when you tack them, correct? The size of pipe determines the size of gap? When you weld your first (root?) pass are you actually (because of the gap) welding the inside of the pipe as well as the outside of the pipe? Very interesting process, looks difficult to do...

noel30
06-03-2011, 07:01 AM
I'm just beginner as well in pipe welding, I just having interest to learn about pipe welding, so probably you can search to net what things you like to know about pipe welding there is lot information about pipe welding. But for me I'm join forum so I can talk personally and gain advice for people learn and exposed in field of welding and I'm glad I found this website that really very helpful to explain and give information about welding.

noel30
06-03-2011, 07:07 AM
Tomorrow I will try to weld again a 4 inch pipe schedule 40, and I will try to apply the land and root opening that give by expert people here in forum and apply there advice. Hopefully I can see improvement on my weld.

weldbead
06-03-2011, 07:46 AM
if you are blowing the bevel away, you're either too hot or too slow or need a thicker land or all of the above..you want to melt the bevel, this is the keyhole..

noel30
06-03-2011, 07:52 AM
Yes I think when I weld last few days the current is too high so the bevel is melted, but when I decrease the 6010 rod is sticking in pipe, especially during overhead of the pipe.

welds4d
06-03-2011, 08:14 AM
Is there a page or link that will show me and explain all the terms you guys are using? I will probably never weld pipe, but I would like to know what you`re talking about haha.... Root opening, land , gap etc?? I understand the pipes are both beveled, then you leave a space between them when you tack them, correct? The size of pipe determines the size of gap? When you weld your first (root?) pass are you actually (because of the gap) welding the inside of the pipe as well as the outside of the pipe? Very interesting process, looks difficult to do...

Good question...

In the US, most pipe beveling is done to 37.5 deg, leaving a 75 deg V when the pipe ends are brought together. The land is the flat left on the end of the pipe when beveled. The thicker the land, the more heat is required to melt it. The root opening is the gap between the 2 pipe ends when they are fit and tacked. The pipe size doesn't dictate the land and gap, it is the welding process that does. For example, TIG welding the root uses little to no land, and Stick uses more land. How much is determined be the type and size of rod, as well as welder preference. As you said, your first pass, or root pass, is to weld the ID of the pipe from the outside. CEP posted some photos that show this quite nicely. Actually the bevel, land and gap are there to allow access to the root, so the entire thickness of the pipe can be welded, making for the strongest joint possible.

monkers
06-03-2011, 08:27 AM
Welds4d, thanks for the info. That's what I thought when I seen his phots, very interesting. I would like to give that a shot one day to see how I do, looks very tough to do right. Great site!

circle ry
06-03-2011, 08:31 AM
Bust out some 3/32 6010 5p for that root you will be amazed by how good the bead goes escpecially on 2'' sch. 40

CEP
06-03-2011, 10:13 AM
Welds4d, thanks for the info. That's what I thought when I seen his phots, very interesting. I would like to give that a shot one day to see how I do, looks very tough to do right. Great site!
Here's a good picture, to help explain.

gordfraser
06-03-2011, 12:21 PM
Bust out some 3/32 6010 5p for that root you will be amazed by how good the bead goes escpecially on 2'' sch. 40

3/32" = 2.5mm
he said at the start he was using 2.5mm