NEED HELP WITH E7018 ROOT PASS

Date 03-19-2006 22:17

7018 has a tendency to close the gap has you weld. The technique that our welders use is stated below:
1- 4 tacks @12;6;3;& 9
2- start first to weld from 9 and progress to 10:30, i assume this will be your first stop.
3-now go down to 6 and progress to 4:30, this will be your next stop.
4- next complete from 10;30 to 12
5- next complete from 3 to 12.
6- complete next from 4:30 to 3
7- last complete next from 6 to 9.
If you start form the bottom and go to the top, quite often the pipe will draw together and you will have difficulty getting penetration on the upper half.
To get good penetration progress upward moving the rod forward, now the walls of the pipe will get molton, just withdraw the electrode for a moment back into the crater (do not whip). This will give the forwarding edges a split second to cool, as you progress. Keep the same pace.

Need more info. Do a search on 7018.

Good luck!
DH

By samh

Date 03-19-2006 22:29

THANK YOU. DO YOU KNOW WHAT SIZE GAP AND LANDING THEY GENERALLY USE?

By welder5354 (**)

Date 03-20-2006 02:47

The procedure that i gave you was for 6" CS sch.80.
For 2",sch.160, it is a little different.
Gap is 1/8" ( 3mm-3.2mm)
Landing is 3/32" (2.3mm-2.5mm)
If you are allowed, put 2 bridge tacks. One at 9 O'clock and one at
2 O'clock. Then one fused tack at 6 O'clock.
Start at 6 O'clock then progress upto the 2 O'clock side first. As you come to the bridge tack at 2 O'clock, remove it, feather your last crater. Now, continue up to the top.
Now, do the same with the other side. Make sure you always feather your stops and starts.

Hope this helps!
DH

By medicinehawk (**)

Date 03-21-2006 00:33

I would use a strong 3/32" Land and a strong 3/32" Gap. I would tack 9 and 3 o'clock and 12 o'clock. Feather tacks with a grinder, and start the weld at 6 o'clock to 3 o'clock, stop, Fearther tack at 6 o'clock, weld fron 6 o'clock to 12 o'clock (if possible), then finish the final quarter.
If you move deliberately, (and make no mistakes) you san throw in a root pass in less than 5 minutes on a standard 2" XX-carbon coupon.
The key is to keep the "keyhole" from opening up past the size of the filler rod 3/32". If you run hot enough 85-90 amps and really Move once you see you are penetrating, it 's really not that bad. It is when "things" happen that slow you down (failed to penetrate, opening up a big hole.etc.) that heat starts to build up (on the coupon)......could mean a big mess.

By J-GROVE JER Date 03-26-2006 16:44

THE ADVICE THE OTHER GUYS GAVE YOU SOUNDS REALLY GOOD AND I HAVE HEARD THAT YOU SHOULD RUN YOUR ROOTPASS IN STRAIGHT POLARITY AND CHANGE BACK TO REVERSE POLARITY FOR HOT PASS FILL AND CAP. TRY THIS ON A SCRAP PIECE OF PIPE FIRST BECAUSE IT IS ONLY SOMETHING I HEARD SOMEWHERE GOOD LUCK WITH THE TEST.

By welder5354 (**)

Date 03-27-2006 01:49

Sorry, but if the procedure calls for DCEP, then that is what the welder has got to follow. Any welder doing a welder performance test must follow the parameters on the welding procedure. If the welder does not stay within the the parameters on the WPS, then that is just cause for the inspector to reject his coupon. For all you new welders, please make sure you get a copy of the WPS before you begin your welding test.
DH

By Anthony James (*)

Date 03-27-2006 15:55

Hi from across the pond
Hi Samh,
As it is 2",i would use 3 tacks,3,9,12 o'clock then when you set pipe up turn pipe so that 3 o'clock is at 5 o'clock,gives you a run from 5-11 o'clock.Useing bullets not tacking in root gap.
Gap 3mm/1/8"
Root face,i like a feather edge with 1mm face.
Amps,50-65 DCEN
Never heard of or seen a WPS that asks for root to be put in DCEP with Lo-hyd.
Hot pass and fill DCEP.
WPS is a guide line,and i have seen lots that make you think,where did the guy who wrote this get his info from.
Had one the other week,s/s 17mm,1mm wall,amps 45!.Been welding this quite alot recently and i use 25/26 amps.That is what i used and everything passed.Cryogenic work by the way.
Hope this helps,and good luck with your test.

Anthony James

By CWI555

Date 04-13-2006 00:10

Sound advice, I've had to kick more than one for the very reasons you've just described. We don't have the option to varie from that either.

By Jim Hughes (***)

Date 03-27-2006 21:08

How much welding have you done? Have you ever ran E7018 on straight polarity? Good luck. Also You will have to follow a WPS. When I test welders, I go over the WPS with each welder, safety, and the test booth procedures. If you violate one of these the test is over. You will not be able to change polarity back and forth. The best thing I think you can do is if you have a welder availible to you then practice with 2" XXH until you have a good looking root. Take notes so you will have an idea of how to set your coupon up in the test booth. Or if you have a welding school or vo-tech close by, see if you can buy some booth time. I have been welding since 1981. I always brush up before a test.

Hope that helps
Jim

By J-GROVE JER Date 04-04-2006 02:47

ONLY A Q.C. PLUG WOULD BE AS ARROGANT AS YOU, HOW MUCH WELDING HAVE YOU DONE, ABVIOUSILY NOT THAT MUCH BECAUSE I HAVE NEVER HEARD OF A 7018 ROOT AND THAT IS WHY I SUGGESTED STRAIGHT POLARITY.A NEWFIE I KNOW SAID THAT PROCEDURE WAS USED ON THE HYBERNIA OIL PLATFORM AND I STILL FIND IT HARD TO BELIEVE, AND BUDDY SAID, ANYTHING WILL HELP .AS FOR MY EXPERIENCE 19YEARS IN THE ALBERTA OIL PATCH . B WELDER PIPEFITTER ,STEAMFITTER AND GAS FITTER ALL WITH SOUR GAS PLANT BACKGROUND.
I AM JUST A GUY THAT THE TOOLS.

By welder5354 (**)

Date 04-04-2006 03:44

Hi J-GROVE JER, I,m am Newfie. Just to get things straight, 7018 root pass was only used in Hibernia with welders having to qualify with the CWB group. All other welders had to have GTAW process (first pass)+ SMAW fill and cap.
The come-by-chance oil refinery in Newfoundland will not allow any welder(s) onto their site without first being qualified to 7018 all the way. An F3 root pass is not permitted on that site by any contractor.
If there are any UA Plumbers and Pipefitters out there, just go to the UA web site and you will see that they have a registered procedure for 7018 (UA-18) all the way.

By medicinehawk (**)

Date 04-04-2006 08:23

Back in 1985, The procedure you are talking about (SMAW-7018-root-fill-cap) on 6"-XX carbon pipe WAS the procedure for certifying as a pipe welder in one of the New England states........It was one of the hardest things I ever did, but I managed to pass it with alot of practice.
Could I pass it again??? Yeah, but with alot of practice.
Now I have heard that that state I hinted at will give you the option of using 6010 for the root pass if you would rather. Go figure.
Anyway, since 85' I have never had to run a 7018 root pass on pipe since. Good Luck with that.

By Sean

Date 04-04-2006 20:18

J-GROVE JER

Just because you haven't heard of it doesn't mean it doesn't exist... keep in mind of where you are and the application and code requirements. Its done everyday on the east coast of Canada and we have sour gas applications too! Welder5354 is right North Atlantic requires F4 roots... and I know for a fact that Alberta has welders with CWB SMAW "T" classification, "O" class tickets for 7018 - which is essentially a 6G pipe ticket with a F4 grouping.

If some of the engineers had a better understanding of welding, what was actually possible, it didn't take as much skill and there wasn't a labour shortage for skilled welders (which is why you are getting good welders from Newfoundland that can do a 7018 root) you would be using 7018 for your root...

If I were you I'd be a little more open minded and try it instead of saying it can't be done...that kind of attitude gives the welding trade a bad name.

By Dr. D

Date 04-07-2006 10:50

I recently talked to a CWI to upgrade my cert. and he also suggested if I can do a 7018 open root on pipe I would be much more qualified to do a wider range of jobs.

By welder5354 (**)

Date 04-08-2006 06:10

Dr. D, you will only be qualified to weld according to your WPS. Having said that, if you are qualified to weld with f3/f4 (ASME Code), then if you upgrade and do another test (F4-open root joint) within 6 months, then your wider range of jobs will allow you to weld with either f3/f4 or f4-open root joint. It is unfortunate that the ASME code, SectionIX is not interpreted by all inspectors equally. I'm Canadian and each province under the Provincial Boiler Regulations seems to interpret the code a little different. Here in Newfoundland we stand by the 6 month code (if you do not weld within the 6 month period, then your certs will expire), Alberta is 2 yrs; I think Nova Scotia is one year and New Brunswick is 2 years. Maybe your country of origin is still different from ours.
Also, Dr.D, if you were tested for f3/f4 in Jan.01/06, then you did another test (f4) in May 01/06, then automatically your f3/f4 will be renewed for another 6 months along with the f4. So now you have two certs, instead of one, for another 6 months.
In this province we allow our welders to transfer from company to company without being recertified, other provinces will make you do a new test everytime you change company's.

By Shane Feder (****)

Date 04-09-2006 06:56

Welder 5354,
QW 490.4 states that Current or polarity is only a supplementary variable which means it is only an essential variable if the code you are working to requires notch toughness tests be performed.
This means a welder can put his root run in using DCEN or DCEP in his weld test and in production. However some electrodes are made to only run properly on a certain polarity. E7018 (in my experience) should never be run DCEN.
F3 without backing (open root) qualifies you for F1,F2 and F3 without backing.
F4 without backing (open root) qualifies you for F1,F2,F3 and F4 without backing.
Not sure what you mean by an upgrade (wider range of jobs) of your qualifications by doing a weld test within 6 months.Does it not purely mean your original qualification has just been extended?
Do they use E7018 for root runs on pipe in the US / Canada ?
Why would you not use E7016 for the root runs ?
Regards,
Shane

By welder5354 (**)

Date 04-10-2006 11:23

Does it not purely mean your original qualification has just been extended?
Shane, your original qualification will be extended for another 6 months (BASE ON ASME CODE SECTION IX).
Do they use E7018 for root runs on pipe in the US / Canada? I cannot speak for the US or all of Canada. But, here in the province of Newfoundland (Canada) we use F4 root passes, just as much as we use F3 root passes by contractors.

By Sean

Date 04-10-2006 18:24

E7016 is not as readily available as the E7018. E7018 is used on root runs on pipe, particularly for "offshore" related work or if the pipe is used for structural applications.

By 357max

Date 04-13-2006 14:20

July 2004 pp.38-41 Welding Journal "Welding Root Beads in P91" ..."Fluor Corporation recently qualified and successfully completed the first production welds in North America using Bohler Thyssen's newly developed Thyssen Chromo T91 E 9018-B9-H4 electrode with the shielded metal arc welding (SMAW) process. According to the manufacturer, this low-hydrogen electrode was developed for uphill welding using either alternating current (AC) or direct current (DC) electrode negative (DCEN), or direct current electrode positive (DCEP) polarity, and for depositing root beads using DC with excellent weldability."
"Table 1 - Welding Parameters
Bevel Angle 37 1/2 degrees
Root Face (land) 3/32 in.(2.4mm)
Root Opening 1/8 in. (3.2 mm)
Root Bead 1/8 in.(3.2mm) Balance 3/32 & 1/8 in. (2.4 &3.2mm)
Root Pass DCEN 72 amps 19.6 volts
Travel Speed Stringer 2.4 in./min (1.0 mm/s)"
Esab has the Sureweld SW-70LA-2 (E7016) and Lincoln has the Pipeliner 16P which is a 7016 H4. Lincoln also has the Pipeliner LH-D80 which is the 7048 which of course is a low hydrogen deposit with the capability of downhill travel. Open root/hot/fill & cap.
Welding 7016/18 with AC (if available) for the open root is a means of controlling the heat input. The squarewave AC output may be the arc easiest to control in the open root.
A good test is worth more than a thousand opinions.

By CWI555

Date 04-13-2006 00:36

As a general comment, getting hostile or rude serves no one nor a given purpose. It's my experience that all groups ( welders, inspectors, fitters, and everything in between ) can help each other far more than they have been the past few years. The number of skilled welding, fabrication, and inspectors, have been on a steady decline for some time now. Part of the reason for that in my eyes, is the negative attitude displayed by each group toward another, and within each group individually. It's hard enough to find a young person willing to work these days, and then when you do, the last thing they need to be seeing is a bunch of old farts going at each other. These young folk like it or not are necessary for the continuance of our world as we know it and the world of the future. I suggest we help them in any way we can in a courteous and professional manner, without resorting to negativity, condescending attitudes, and infighting. Young folks starting out or even older folks changing careers, tend to question what they are letting themselves in for when they see and hear things like that.

I myself find that I learn from such people. No ones told them they can't do it, or it's impossible, and from time to time they come up with a solution I've never seen before.

I've worked to different codes/standards around the world, and I can assure every reader, for every way you can think of to acomplish a given task, theres likely to be 10 others out there somewhere you've never heard of. No body ever reaches the goal of knowing it all, no matter how much experience they have.

Just a few long winded thoughts for consideration.

By rick.miller Date 04-18-2006 14:43

I ran into the same situation several years ago and was lucky enough to work with some Scotts fellas fresh from the oil rigs in the North Sea where this is the standard procedure. The 7018 Root pass instead of conventional 6010 takes some getting used to. But like all welding there are little tricks. First I woulduse a 3/32" Land and Gap, now the "trick", use DC- for the root. Yes! Straight Polarity for the root. It will give you a very deep penetrating weld but you will not see a keyhole like you do with 6010. I like to use a hacksaw with (2) blades side by side to feather the both side of my tacks and the end of each pass. You will have no problem getting in a root this way. Be careful some inspectors are fussy and will make you adhere to the DC+. Just switch the cables around without anyone looking. You will notice a different sound, but the root will go in great.

By jarsanb (***)

Date 04-18-2006 16:15

Or maybe prove this out and revise the procedure hence some state and federal standards aren't just a "guideline" as mentioned above. I know what you are saying, but this would have very costly fines/discipline in some areas.

By welder5354 (**)

Date 04-18-2006 17:01

Hi Rick, I hope you are only a rookie and not somebody with years of experience. Teaching those new welders dishonesty in the work place could cost them their job. The welders in our union do hundreds of 7018 root passes each year with no problem. If the procedure calls for 7018 root pass, then that means somebody had to do the qualifiing procedure, so therfore, all other welders should be able to perform the same welds.

By hogan

Date 04-18-2006 17:17

poor idea rick

By Shane Feder (****)

Date 04-19-2006 01:07

Hello guys,
I have previously spent 15 years as a pipe welder with the majority being GTAW root - E7018 fill & cap / E6010 Root - E7018 fill & cap / and E7016 root - E7018 fill & cap.That is why I asked (in an earlier posting) about the E7018 root in the US / Canada as I had never heard of it before.
I also stated (in an earlier posting)that in my experience E7018 should not be used on DCEN. This was based on past experience filling and capping where you generally always ended up with a substandard run full of porosity.
After doing some research on this I will admit I was wrong and certain E7018 electrodes are made to run on DCEN (root runs only).
I am using Australian electrode manufacturers recommendations but I don't think they differ greatly from your side of the world.

E7018 DCEN/DCEP or AC (preferred polarity for filling & capping is DCEP)
E7018-G DCEN/DCEP or AC (preferred polarity for filling & capping is DCEP)
E7018-1 H8 DCEP
E7018-1 H4 DCEN/DCEP or AC " The 2.5 mm 18TT is a special root running electrode displaying excellent AC arc stability down to 55 OCV and smooth DCEN performance in wide root gap preparations."

AWS D1.1 Table 4.5 (13) and ASME IX QW 253 (QW 409.4) both state that change of polarity is a non-essential variable for the WPS.That means that you can qualify the procedure with the root run DCEP and at a later date you can then run the root run with DCEN without requalification of the procedure.The same for welder qualification, if they qualify DCEP they can put a root run in using DCEN without requalification.
On my PQRs I have the polarity used during the PQR test and on the WPS I have DCEN/DCEP with a note stating "as per manufacturers recommendations."

Regards,
Shane

By jarsanb (***)

Date 04-19-2006 14:40

API 1104 18th 2.4.2.7 "A change from DCEP to DCEN or vise versa or a change in current from DC to AC or vise versa constitutes an essential variable."
This is for procedure qualification. The 19th edition would be 5.4.2.7 and not sure if criteria is the exact same - but I believe it is.

By webbcity (***)

Date 04-19-2006 15:26

jarsanb , thats the way i read it . 5.4.2.7 electrical characteristics . i havent got my new 20th edition ordered yet . willie