ED'S
PIPE WELDING ROBOT:
WITHOUT QUESTION, A SIX AXIS ROBOT COULD BE ONE
OF THE MOST VERSATILE TOOLS USED FOR
AUTOMATED PIPE LINE WELDING.
.
In
1997 I set the weld data with an ABB robot to weld this 48 inch steel pipe. I
used short circuit transfer for the vertical down root. The robot pipe fill pass
welds were made in the vertical up position using an 0.052 Alloy Rod Dual Shield
E71T-1 wire with 80% Argon - 20% C02. The robot flux cored pipe weld deposition
rate was "ten pounds an hour"
The high flux cored weld deposition
rate, combined with the fast robot movement between welds, (faster than any other
available automated pipe weld equipment) provides greater pipe line weld production
potential than any other available automated pipe weld unit.
In 2007 there is still no automated, mechanized pipe line weld unit available
that can offer the flexibility or weld process communication of a six axis robot
for welding pipe bevels. A robot provides many unique features for pipe welds.
[a] accurate, flexible through the arc weld joint tracking,
[b] adaptive
controls that can compensate for different welding conditions,
[c] super fast
speeds between welds,
[d] superior communication with the welding power source.
Combined these features offer the world's greatest automated pipe welder.
Just
imagine, one day we may then see two small robots hanging down, mounted on a "ROBO
RIG" truck, that traverses that Texas, Canadian pipe or Middle East pipe
line.
ED'S
1997 "ROBO RIG", PATIENTLY WAITING
FOR A SLEEPY INDUSTRY TO RECOGNIZE OPPORTUNITY:
 |
ED'S 1997 SHOP OR FIELD ROBO RIG: Two
automated pipe welding carriages welding with MIG and flux cored wires, attached
to two sophisticated electronic power sources can cost over $130,000 Two robots
attached to two power sources could cost approx. $100,000. The pipe welding robots
could be mounted on a portable tractor driven gantry for field pipe applications.
[] Robo Rig: With two pipe welding robots hanging upside down,
you have a mechanized unit that offers automatic touch joint sensing, through
the arc impedance joint tracking, adaptive weld controls that will compensate
for pipe joint deviations. For the pipe shop, simply present the pipe to the gantry
and tell the robot the required weld schedule to use. For that pipe line, drive
the Robo Rig over the weld joint. In less than 10 seconds the robots or robot
will locate the pipe bevel and pipe root. Setting track for two less flexible,
two axis mechanized carriages can easily take 20 to 30 minutes.
[] The
Robot Rig will dramatically reduce the total pipe weld time. At the end of a fill
pass weld, a robot can be in place to weld the next fill pass within 3 seconds.
[] The Robo Rig will have a flexibility that far surpass any automated pipe
welding carriage. This flexibility will optimize the robot weld gun positions
for the all position pipe welds. The robot can automatically sense a weld direction
or side wall dimension change and instantly provide weld speed, weld direction
and process changes to compensate.
[] The robot can change tools in seconds,
one minute it's welding the next minute it's cleaning the slag from the welds.
[] The Robo Rig will have far superior communication
and will store as many weld schedules as you will ever require.


IT'S
GREAT TO SEE OUTSTANDING
PIPE WELD EQUIPMENT

INSTEAD
OF THE ROBO MIG FROM ED, WE HAVE THE GERMAN VIETZ LASER PIPE RIG:
While
some companies think that using STT or RMD MIG and the flux cored process on pipe
welds is progressive, Vietz is developing a new laser welding system which aims
at economic welding of pipelines.
A
generator installed on the ARCOTRAC welding tractor supplies the laser source.
The laser source is connected the to laser welding head by means of a fiber laser
cable. The laser power can be transported to the laser welding head over a distance
of up to 80 m. The pipes are centered and fixed to each other by means of a clamp,
the pipe edges being butt welded.
The
laser welding head - fixed on a band, rotates around the pipe. The result of this
laser welding system is a welding speed and efficiency which is not comparable
to any other welding system. A pipe of 1,000 mm diameter with a wall thickness
of 15 mm e.g. can be completely welded within 2.5 minutes.
Note
from Ed. The laser weld will take 2.5 minutes as long
as there are no laser, pipe dimension, preperation, contamination, culture, process
education, or people issues. Good Luck. For those that want less complexity than
the highly sensitive laser and would like the opportunity to sleep 8 hours a day,
I would suggest my simple Robo Rig or a less costly Bug-O with all position flux
cored wires..
WHEN
IT COMES TO MIG OR FLUX CORED PIPE WELD ISSUES IN THE CHEMICAL, OIL AND POWER
INDUSTRIES, MIG AND FLUX CORED WELD PROCESS EXPERTISE WILL ALWAYS HAVE A GREATER
IMPACT ON THE PROJECT THAN THE WELDING DOLLARS SPENT ON COSTLY ELECTRONIC WELD
EQUIPMENT.
WHY WORRY ABOUT THE TIME REQUIRED FOR PIPE
PRE-HEAT,
WITH THE VIETZ UNIT IT ONLY TAKES SECONDS:
Depending
on the pipe quality it is typically necessary to preheat the pipe ends within
a very short period of time. The new technology being installed on the Vietz ARCOTRAC
welding tractor has been designed to reach 300o C within the shortest period of
time (approx. 60 seconds).
J Ray McDermott Inc. of Houston TX gets the message,
automate, provide process controls and strive to keep it simple
With
an updated automatic pipe-welding system, J. Ray McDermott Inc. (Houston, TX)
continues to help set world production records for laying oil and natural gas
pipelines up to 38" (965 mm) in diameter and over 0.500" (13 mm) in
wall thickness. This is due in large part to having reduced
the complexity of its machine control scheme.


Flux
Cored

WHEN
WELDING PIPE WELDS, CAREFULLY EVALUATE THE GAS SHIELDED FLUX CORED WIRES AVAILABLE,
THERE ARE SOME TERRIBLE PRODUCTS OUT THERE.
IF YOU WANT TO SEE GOOD VERSUS
MUNDANE ALL POSITION E71T-1 WIRES, COMPARE A GREAT RUNNING ESAB (ALLOY RODS) DUAL
SHIELD OR KOBELCO WIRE AGAINST WHAT I BELIEVE IS A LESS THAN OPTIMUM LINCOLN,
COREX OR HOBART FLUX CORED BRAND WIRES.
E-mail From John Hoffman. June 06/06:
I
use all position 0.045 1.2 mm, gas shielded flux cored wires. I have been utilizing
Lincoln's 71 M Outershield. Too frequently I get lots of porosity and worming.
I would like to try something that works consistently. Ed
what would you recommend?
Regards
John.
Ed's
answer: I have had many weld porosity and, worm track issues
with all position Lincoln wires and also found that in contrast to some other
wires, the Lincoln wires offer a lower wire feed range reducing the hourly weld
deposition rate potential.
IF
YOU WANT OPTIMUM AND CONSISTENT WELD PERFORMANCE FROM E71T-1 FLUX CORED WIRES,
CONSIDER ESAB (ALLOY RODS) OR KOBELCO WIRES.


And
the best power source for
all position E71T-1 wires is?

The
lowest cost, CV MIG power source is better suited to
flux cored wires than
the most costly inverter or pulsed power source.
Want
European "confused" MIG Gas Standards Data?
Visit
http://www.key-to-steel.com/GuidedTour.asp
Want European confused welding
standards? Visit here
Keep the flux cored wires in an oven or warm dry location
to avoid porosity, worm tracks and hydrogen cracks.
E-mail 2005. Dear Ed, Your information in the Management Engineers
book has been great!!! As I read your book, it seems like you have been inside
my brain. We are now breaking away from SMAW and will be implementing Flux Core
on our fill and cap passes. I will keep you informed and thank you.
Matthew
Panconi
Executive Vice President Sylvan Piping NJ.
Ed Testing MIG and Flux
Cored Wires on Gas Pipe.

IN
2003, ED COMPLETED A PIPE WELD PROCESS RESEARCH PROJECT FOR IMPERIAL OIL, ALBERTA,
CANADA, (THE COLD LAKE WELD PROJECT). THE PURPOSE
OF THE RESEARCH, TO EVALUATE THE LINCOLN STT MODE VERSUS TRADITIONAL SHORT CIRCUIT
FOR THE ROOT AND ALSO COMPARE DIFFERENT MIG, METAL CORED AND FLUX CORED WIRES
FOR THE FILL PASSES.
PIPE
MIG WELD WIRES: IF
YOU WANT OPTIMUM, STEEL MIG WIRES FOR PIPE ROOT WELDS CHECK OUT AN ESAB OR LINCOLN
L50, WIRE VERSUS THE COMMONLY USED E70S-X K NOVA MIG PIPE WIRES AVAILABLE FROM
THYSSEN.
THE THYSSEN MIG WIRE
I USED FOR THE COLD LAKE PIPE ROOT RESEARCH PRODUCED A SLUGGISH, FAST FREEZE,
SHORT CIRCUIT WELD, A WELD POORLY SUITED FOR ANY PIPE APPLICATION.
DURING THE PIPE WELD AND WELD CONSUMABLES TEST, I ALSO EVALUATED
A NUMBER OF METAL CORED WIRES FOR THE PIPE ROOT WELDS, AS
I SUSPECTED WITH TRADITIONAL SHORT CIRCUIT TRANSFER THE METAL CORED WIRES PROVIDED
NO WELD BENEFITS. IT WAS A WASTED EFFORT.
FOR
THE PIPE RESEARCH PROJECT, I ALSO TRIED E80S- D2 MIG WIRES FOR THE ROOT, THESE
HIGHER TENSILE MIG WIRES PRODUCED GOOD WETTING IN THE ROOT WELDS AND WITH THE
LINCOLN STT PROCESS, THERE WAS NO ISSUES WITH THE E80S-D2 WIRE. WITH SHORT CIRCUIT
TRANSFER, THE ROOT WELDS WITH THE 80S-D2 WIRES PRODUCED A VERY BENEFICIAL FLAT
SURFACE, ALWAYS LESS CONVEX THAN THE TRADITIONAL E70S-X MIG WIRES. KEEP IN MIND
THAT THESE HIGH STRENGTH WIRES OFFER LESS DUCTILITY THAT THE E70S-X WIRE SO THEY
COULD BE MORE PRONE TO HOT CRACKS IN THE SMALL ROOT WELDS.
Set the flux cored wire, so the tip of the wire as close as possible
to the weld (arc length) without causing weld spatter

Fine
tune the arc length with voltage control.
A
LOW COST, FAST SOLUTION TO YOUR ROBOT AND MANUAL WELDING ISSUES.
Phone
/ E-mail Weld Help. Ed has resolved over 1000 companies weld issues. Many weld
issues can be resolved on the phone or by E-mail.
[]
Are you having robot or manual weld issues that affect your weld quality productivity
or down time? [] Are you ready to purchase weld
equipment, gases or consumables and would rather not waste your money? []
Do you want the best method or procedure for a specific MIG / FCAW / SAW / PLASMA
/ GTAW application?
Call Ed at 828 658 3574,
(eastern standard time USA). or
E-mail ecraig@weldreality.com The
typical weld resolution fee is $375 paid in advance
with Visa or MC.
Plant
Weld Help... Ed will also visit you facility and
provide hands on, instant solutions to all your robot / manual MIG / flux cored
/ GTAW / SAW / Plasma weld issues. Perhaps you require assistance in establishing
Best Weld Practices or Weld Process controls. You may want to dramatically improve
your manual or robot MIG / flux cored weld quality and productivity with one of
Ed's unique, one day, highly cost effective weld process control training programs.
Cost
$1275 daily plus exp.
|

LIKE SMAW ELECTRODES, ALL FLUX CORED WELD CONSUMABLES ARE
NOT CREATED EQUAL.
With
the common USA gas shielded FCAW products, be aware that for vertical up MANUAL
structural / pipe / pressure vessel welds on carbon steels, you can attain a higher,
stable weld deposition rate from an ESAB all position, gas shielded flux cored
consumable than you can from a similar Lincoln - Hobart - Corex flux cored product?
Remember weld
deposition rates are a primary influence on pipe line weld costs.
When evaluating the gas shielded flux cored wire electrodes, for optimum welds
you will require a stable/small droplet weld transfer.
When evaluating all position flux cored wires;
[a] Look for erratic larger
drops, globular type weld transfer in the flux cored, recommended wire feed range.
The glob weld transfer will provide excess weld spatter, cause arc and weld stability
issues and destroy the contact tip in the over head weld positions.
[b] Examine how easy the flux cored weld slag falls
off the multi-pass welds. [c] Look at the
wire feed settings and evaluate the MAXIMUM weld deposition attained. Ed's books
show both optimum wire feed settings and deposition rates. [d]
Examine the flux cored wire feed range and learn the low and high spots
in which you can control the weld puddle in the overhead and vertical up weld
positions. My books describe a simple method on how to set optimum weld
data and evaluate a gas shielded flux cored
wire. |

Purchase
a process control book
and become
a welding pro.
BEST NORTH AMERICAN
GAS SHIELDED
FLUX CORED WIRES.
For
the best North American, all position E71T-1 gas shielded flux cored wires, I
recommend ESAB 1.2 mm (Alloy Rods) products. I also like the Kobelco wires from
Japan.
While I recommend Lincoln "L50" MIG wires, I have never
recommended the Lincoln gas shielded flux cored products as I found they have
many weld issues. In their optimum weld parameter range, the all position Lincoln
E71-T1 wires I tested provided erratic weld transfer which suggest chemistry imbalance
or chemistry inconsistency, also extensive worm tracks resulted. In contrast to
the ESAB E710X wires, the Lincoln E71T-1 gas shielded wires also provide a narrower
optimum weld parameter range, with less control of low and high amp settings.
For the weld shop this means that the Lincoln wire I tested provided less weld
deposition rate and less weld fusion potential for vertical and horizontal welds.
Remember
with flux core, the adjustment of the arc
length is critical for vertical
up weld control.
Volts
too high weld too fluid.
Volts too low, weld spatter.
WANT TO SAVE A MILLION DOLLARS ON YOUR NEXT
SMAW PIPE LINE PROJECT? CLICK
ON
" ED'S REAL WORLD
APPLICATIONS".

There
are many engineers involved with pipe, pressure vessel fabrication that have strong
negative opinions on the MIG, pulsed MIG and flux cored weld process, yet
few of these engineers will have extensive MIG or flux cored weld process control
expertise.
IF
YOU TAKE THE CULTURE OUT OF WELDING, LIFE WOULD BE BORING.


A
comment from Mr. Bubba B. Brown Junior.
President of the BB Oil Pipeline Inc.
" Boys, for this pipe weld project, I want you all to keep the automated
and pipe weld equipment costs to a minimum. We need the ability on this project
to keep the weld operation as simple as possible.
I want the key weld decision makers in this organization to be aware of the reasons
they have to justify the purchase of so the called sophisticated electronic pipe
line welding equipment.
Bubba
continues. From now on I want my weld team to "ignore
weld sales advice" and start make rational welding decisions for themselves.
Dam it men, we need to cut through the BS that surrounds this MIG and flux cored
weld process and stop hiring wimp wristed project managers and supervisors who
believe the only way to weld a pipe is with a Lincoln
E6010 electrode stuck up their rear end.
Bubba concludes and his blood pressure
is getting pretty high. You
boys take note, this is the bottom line:
[] I want this organization to
be known as a
cost affective, dynamic
company that consistently delivers optimum weld quality and delivers it's products
always on schedule.
[] I want this companies weld decision makers to have
the ability to differentiate between process and equipment bells and whistles
and cost effective weld benefits.
[] I want this organization to ensure
the processes utilized are made simple to operate and the equipment purchased
is both logical and durable.
[] Finally, I want each engineer and manager
in this organization to go home to night, look in the mirror and repeat this.
" I am responsible and accountable for all the process decisions made in
this organization. I will do my utmost to establish Best Weld Practices for this
organization and for my sub contractors. I will ensure that all weld personnel
involved in this companies welded products receive the Process Control Training
necessary for Process Optimization.
WE
ALL KNOW THAT TO FIND A PRACTICAL, PIPE COMPANY PRESIDENT LIKE BUBBA, YOU WOULD
HAVE TO HAVE A VERY VIVID IMAGINATION OR TAKE A LONG TRIP.


ESAB
has introduced a new E71T-1 (Alloy Rod) wire called the E710X. This wire works
well with CO2 or argon CO2.
This flux cored wire is different in that the CO2 or
argon CO2 wire feed, amps and voltage relationships are
almost the same. This wire therefore has an extensive, low to high optimum wire
feed and amp range making it easy to use with CO2 on a very
wide thickness range.
Note:
Before using this wire be aware that the moisture pick up potential may have increased
influenced by the chemistry composition changes made to this wire. Before using
on a large job job I recommend getting some experience with this wire.
PIPE
WELDS & WELD PROCESS QUALIFIED?
Today,
pipe line weld decision makers have many weld process and process combination
choices when welding the pipe fill and root passes.
[1] Stick root / stick
fill.
[2] Stick root / flux cored fill.
[3]
Stick root / pulsed MIG fill.
[4] TIG root /
stick fill.
[5] TIG root / TIG fill.
[6]
TIG root / pulsed MIG fill.
[7] TIG root / flux
cored fill.
[8] TIG root / metal cored fill.
[9]
STT root / your choice for fill.
[10] CMT or
RMD root / your choice pulsed
or FCAW for fill.
[11] Globular MIG, Pulsed
MIG for pipe ID and Pulsed MIG and flux cored for fill.
[12] Laser, Laser Hybrid
or twin wire.
There
are always many opinions on the weld process and consumable selection for that
pipe or pressure vessel application, yet I wonder how many people in the industry
are sufficiently "weld process qualified" to make a rational process
choice for a pipe root pass when evaluating the Short Circuit, Globular, STT,
CMT or RMD weld transfer modes?

Weld process control is measured by process expertise, would
you like to try this fundamental weld process control weld
test?
WHEN
AN INDUSTRY OR CORPORATION SUFFERS FROM WELD PROCESS APATHY OR IS SLOW TO GRASP
THE WELD BENEFITS DERIVED FROM WELD PROCESS OR CONSUMABLE EVOLUTION, THE WELD
DECISION MAKERS WILL OFTEN IMMERSE THEIR HEADS IN THE WELD SHOP SMOKE, SHY AWAY
FROM PROCESS CHANGE AND NURTURE THEIR RELATIONSHIPS WITH
THE LOCAL WELD SALES REP.
A
LOW COST, FAST SOLUTION TO YOUR ROBOT AND MANUAL WELDING ISSUES.
Phone
/ E-mail Weld Help. Ed has resolved over 1000 companies weld issues. Many weld
issues can be resolved on the phone or by E-mail.
[]
Are you having robot or manual weld issues that affect your weld quality productivity
or down time? [] Are you ready to purchase weld
equipment, gases or consumables and would rather not waste your money? []
Do you want the best method or procedure for a specific MIG / FCAW / SAW / PLASMA
/ GTAW application?
Call Ed at 828 658 3574,
(eastern standard time USA). or
E-mail ecraig@weldreality.com The
typical weld resolution fee is $375 paid in advance
with Visa or MC.
Plant
Weld Help... Ed will also visit you facility and
provide hands on, instant solutions to all your robot / manual MIG / flux cored
/ GTAW / SAW / Plasma weld issues. Perhaps you require assistance in establishing
Best Weld Practices or Weld Process controls. You may want to dramatically improve
your manual or robot MIG / flux cored weld quality and productivity with one of
Ed's unique, one day, highly cost effective weld process control training programs.
Cost
$1275 daily plus exp.
|
ED
TESTING MIG SHORT CIRCUIT
VERSUS STT / RMD MIG TRANSFER ON A PIPE ROOT.

2006:
NEW FROM MILLER, THE MULTIPURPOSE
PIPE PRO 450 POWER SOURCE:
Finally after two decades of deep weld process sleep, Miller has woke up and is
on its slow way to the development of a weld power source that can provide a few
real world weld benefits for a pipe shop.
Before you consider the
over priced, often unstable Lincoln STT/ Power Wave that sells with a wire feeder
for approx. $13.000, you should examine the over priced $11.000 Miller Pipe Pro.
Someone might ask, how can Lincoln or Miller justify the price of a car for the
price of a pulsed MIG weld power source?
The
Miller PipePro is a multi-process power source that
can do many of the welds performed on common carbon / stainless pipe welds. The
unique attribute of this power source is a Miller development called RMD (Regulated
Metal Deposition).
RMD is an
electronically modified MIG short circuit transfer weld
suitable for all position pipe root welds. The PipePro can also use a low deposition
pulsed mode the Pro-Pulse
that actually works for all position pipe fill passes. You can also use this power
source higher deposition flux core for the fill passes

Before
you spend $11.000 on a multi-process power source for your pipe shop keep in mind
the following.
[]
If most of the pipe you weld is under six inch OD and you have traditional $3000
MIG and TIG equipment and flux cored consumables. Using TIG for the root welds
and flux cored for the fill passes is a great cost effective way to go.
Note: Minimal skill is required with the RMD VERTICAL DOWN ROOT WELDS HOWEVER
CONSISTENT ROOT DIMENSIONS IS REQUIRED.
[]
If you can rotate many of the pipes you weld, you don't need the $11.000 RMD for
the root, consider regular short circuit transfer available from a $2000 MIG power
source, its just as good.
[] If many of the pipes welded are > 3/8
(> 9 mm) wall thickness, the flux cored process in contrast to the lower deposition,
lower weld fusion potential pulsed MIG will always be the best choice.
Note: In contrast to pulsed MIG, the flux cored process provides higher deposition
rates (200%) superior side wall weld fusion and requires less skills.
[] Pulsed MIG is good choice on thin wall fill passes < 7 mm and on automated
equipment that prohibits slag between the welds.
FOR
THOSE OF YOU READY TO RUSH OUT AND PURCHASE THAT NEW MILLER PROLINE POWER SOURCE,
BE PATIENT AND DO SOME REAL TESTS WITH THIS EQUIPMENT BEFORE INVESTING CLOSE TO
$11,000.
REMEMBER AT THIS TIME MILLER DOES NOT HAVE THE BEST REPUTATION
FOR BUILDING "RELIABLE AND DURABLE" PULSED EQUIPMENT.
AND IT WOULD APPEAR THAY THEY LIKE THEIR CUSTOMERS TO TEST THEIR EQUIPMENT FOR
THEM.
DON'T
FORGET. ITS VERY COST EFFECTIVE TO UTILIZE LOW COST TIG OR SMAW EQUIPMENT FOR
THE ROOT AND A LOW COST, CV MIG POWER SOURCE FOR THE FLUX CORED FILL PASSES.
And
the best power source for
all position E71T-1 wires is?

]
If you want to establish
Best Flux Cored Weld Practices and Weld Process
Control Training, you may want to consider
MY
UNIQUE BOOK AND NEW TRAINING RESOURCE.
IF
YOU DON'T HAVE STT OR RMD
For
the internal or external 1G horizontal rolled pipe root welds, set the the traditional
low cost, ($2000) CV MIG process gun for traditional "short circuit transfer"
with an 0.035 (1 mm) wire.
For the external root, rotate the pipe clock
wise so you are welding in the vertical down weld position using the drag technique.
For the root provide an 0.080 land with an 0.080 to 0.100 root gap. Set the short
circuit wire feed rate at 250 to 300 ipm (around 11 o'clock wire feed control
position).
Use
16 to 18 volts with argon - 15 to 25% CO2. Let the contact tip stick outside the
gun nozzle and hold the MIG gun at the 2 o'clock position
in the center of the pipe root gap and rotate the pipe anti-clockwise, no weaves
are necessary as long as the root gap dimensions are maintained. This traditional,
low cost process is simple to operate, provides great results and is done with
a CV power source that could cost $1500 to $2500.


For internal
5G, large diameter ID pipe root welds, the all position root settings can be carried
out with either short circuit or the MIG globular mode, welding vertical down.
For the globular mode, use an 035 wire, a gas mix of 10 to 20 CO2 and a wire feed
rate of of 400 to 500 IPM with 20 - 24 volts.
For the external root use the short circuit mode with the parameters and edge
prep dimensions mentioned for the 1G position. At the cap and overhead use an
aggressive weave, while at the vert down 1 to 6 o'clock position and 11 to 6 o'clock
positions just use the drag technique with the wire in the center of the root
gap short circuiting on the leading edge of the fast freeze weld puddle.
The
pipe root pass. This task with short circuit or the newer, modified short circuit
requires minimal manual weld skills and typically
will attain root weld speeds of approx. .10 to 15 ipm. In contrast to a
SMAW or TIG root pass, the MIG process will
be done at least three to four times faster.
Thanks
to the modified short circuit transfer, 11 old Jessie had no problem manual MIG
welding a pipe line root pass,
of course it took 15 minutes of instruction.
As root pass welds are simple and cost effective with modified short circuit MIG
equipment, and pulsed MIG provides low deposition, all position fill pass capability,
the pipe line industry weld cost / quality focus should be on the manual or automated
gas shielded flux cored weld requirements for the weld fill
passes when the pipe diameters are greater than 20 cm and the wall thickness
is > 12 mm.
An Ed excuse for a Joke:

See
how you do with the
flux cored weld quiz.
WELDERS WHO IN THE PAST HAVE BELIEVED THAT "SKILLS"
ARE THE PRIMARY PREREQUISITE FOR ALL POSITION PIPE WELDS, NEED TO UNDERSTAND THAT
WITH TODAY'S CHOICES OF MIG WELD EQUIPMENT AND CONSUMABLES, WELD
PROCESS EXPERTISE IS JUST AS IMPORTANT AS WELD SKILLS.
|
Weld
Question from UK.
Hi
Ed love the site, it's a breath of fresh air. My name is Mick Brennan I work in
the UK. I have been involved with the welding offshore and cross country pipelines
for close on 40 years. Most of that time has been spent using Mechanized MIG Processes.
Some of the processes have involved combination Internal clamping and Welding
Machines. This is a fine process but it can be costly as the Pipe Ends have to
be Prepped with an Internal Bevel and a Narrow Gap preparation on the outside.
The money saved on less deposited metal and less welders gets eaten up with this
change in Bevel Design and the costly Internal Welder. Using this equipment on
shorter pipelines < 20 Miles becomes uneconomical as the pipe weld equipment
is usually rented in and a mob and demob fee erodes the potential profit.
In your
opinion could a Root Pass be applied to a Pipe using a Mechanized External Welding
device, welding vertically down in the 5G position, 60 Degree Bevel, 1.5-2.00
mm Gap. Using a. 035 solid wire at a weld speed of 30 IPM. Wire speed 500 IPM
and wire stick out of 3" with 23.5 Volts measured at the Welding Tip. In
this particular area would the Pulse process be beneficial as Top and Bottom are
prone to burn through and the Vertical is prone to LOP as the puddle outruns the
Welding Tip?
Regards
Mick Brennan. UK.
Ed's
Answer:
Mick
as you know internal, pipe weld roots can be made
with 0.035 MIG wires with a short circuit wire feed rate of 200 to 300 IPM with
16 to 18 volts. Also controlled globular transfer wire feed 350 to 500 ipm, 20
to 23 volts. The MIG settings you provide, WF 500 ipm - 23.5 volts are simply
globular transfer.
The 3 inch wire stick out lowers the weld current
and makes no sense, it does indicates a weld process out
of control, and god help the gas coverage.
IN CONTRAST TO THE LONG WIRE STICKOUT USE A LOWER WIRE
FEED RATE AND WELD
WITH CONTROLLED WELDING CONDITIONS.
For the external
root pass, with the short circuit mode welding vert down from 12 o'clock,
a fixed gap of 3/32 - 1/8 is required and there is good opportunity for weld suck
back and wire stick through at the root 5 - 7 o'clock positions. X Rays don't
like those wire pieces sticking in the inside of the pipe. You should weave at
the top and bottom of the pipe or place long tacks in the 12 and six o'clock positions
to minimize the potential root weld issues.
Modified Short Circuit
versus Traditional Short Circuit

Note:
The above picture is a weld process pipe root evaluation carried out by Ed and
Imperial Oil welders. The STT controlled short circuit current spike "no
spatter" transfer weld mode is used by the welder on the left. The traditional
MIG short circuit transfer mode noted by the spatter is used by the welder on
right.
The
only problem area I had with all position, external MIG pipe root welds which
were made with the traditional MIG / MAG short circuit mode is found
at the 5 - 7 o'clock root area of the pipe.
Thanks to suck back
and weld wire getting stuck inside the root at the over head position, it's difficult
to control the root gap weld quality in this area. The difficult over head root
location on the pipe root pass could readily be welded during the tack operation
using SMAW electrodes or the TIG process. Then use traditional short circuit vertical
down for the rest of the root. Both the MIG short circuit and flux cored processes
can be used with low cost generators with CV adapters OR low cost CV MIG equipment.
MIG
and Pipe Root Tacks

If
the required pipe root dimensions cannot be maintained, the root pass should be
made with the SMAW or TIG process.
GOOD MIG TACK PROCEDURE:
With the short circuit or modified SC mode using 0.035 (1mm)
wire, place three tacks 50mm in length, then feather the tack start / stop edges.
After the root pass is complete take the grinder to the length of the tacks to
thin and blend the tack weld throat. For the pipe prep, with short circuit use
a 2 to 2.5 mm land and a 3 mm root gap.
For modified short circuit no
land is required. Use a 2.5 mm gap and use an 0.045 (1.2mm) wire. Use back hand
vert down. The root throat depth of the MIG root weld will support the next hot
fill pass with pulsed MIG or flux cored wire.
When the gas
shielded flux cored consumables
are
selected for the pipe "fill"
passes,
pipe line companies who cannot build my Robo Rig should examine closely the need
for costly, complex automated pipe weld units, versus a simple automated, carriage
and CV generator for the FCAW pipe fill passes.
FOR SMALL PIPE LINE PROJECTS KEEP IT SIMPLE
AND COST EFFECTIVE:
If given a choice for pipe welding the FLUX CORED
fill passes between a $130,000,00 complex, automated, computerized, pulsed MIG
pipe line weld package or a simple to operate mechanized, carriage / track with
a CC- CV generator. The generator / with the low cost mechanized unit package
can provide the following benefits;
[a]
When manual or automated welding on pipe
lines using flux cored wires, one volt / wire feed amp weld setting is all that
will be required for the "all" the pipe fill, flux cored passes.
( weld speed and weave width will of course change). When
pipe weld operators use many flux cored or MIG "weld parameter combinations"
for multi-pass, fill pipe welds, it's an indication the people who set the equipment
are typically not in control of the welding process.
[b]
The simplicity of the 2 weld parameter controls used with the flux cored process
allows the manual or automated weld operator "easy control and weld adjustment
of the weld process" (especially if they have read my weld process control
books).
[c] The flux cored process provides
greater weld fusion than any MIG mode, it will also provide less porosity potential
and require less welding skills.
[d]
For pipe fill passes only. A simple low cost mechanized carriage attached to the
track that straddles the pipe would sell for $10,000.00 to $15,000.00. The weld
carriage should have the weld controls necessary for weld speed and weld weave
controls. The weld gun would be hooked up to a traditional, field wire feeder
attached to a CC / CV generator. For this weld there is no need for a complex,
pulsed MIG electronic weld power source that offers 20 weld schedules and a dozen
different ways to weld steels, stainless or aluminum.
The
use of flux cored wires for all position pipe fill passes will in contrast to
any MIG weld transfer mode, be simpler to use, easier to operate and produce much
higher weld deposition rates with superior side wall fusion.
Note: If optimum flux cored consumables are selected and
the flux cored weld data is correctly applied, as the following photo indicates,
all the welds will be made with one set of weld parameters with changes only for
the weave data. If the weld data is correct the pipe
weld slag should fall off almost
without assistance.
Ed's
Simple Clock Method (in all his books)
for optimum
MIG and flux cored weld parameter selection.
Correct FCAW Parameters "WOW".

E71T-1
FCAW: EASY SLAG REMOVAL IF YOU USE
THE RIGHT
WELD WIRE AND OPTIMUM PARAMETERS:
The pipe weld root joint
will sometimes as a result of poor fit require special considerations. The SMAW,
TIG process should be given consideration when the root gap cannot be controlled
If welding the pipe line root weld on the "inside"
of the pipe, the traditional low cost, CV, MIG equipment or a CV adapter on a
CC generator may be used with a MIG wire using;
[1]
a high short circuit setting,
[2] a controlled low globular setting,
[3] a low spray transfer setting with less than normal spray transfer weld volts.
Note: For 1 to 3, the 0.035 (1 mm) wire with argon 15 to 25% CO2 will
provide the greatest control in open root pass welds.
The
following statement is one many highly skilled SMAW pipe line welders will not
want to hear, however it's weld reality.
Using the modified
short circuit mode or traditional short circuit process for the root, a
none-welding individual who has good vision, dexterity and the right attitude
can be trained in a day or two to weld an all position pipe root that will meet
any code requirement.
Lincoln
Invertec STT II
Featuring the Surface Tension
Transfer (STT) Process
List Price:7706.00
The STT II power source
combines high frequency inverter technology with Waveform Control Technology
to provide a better welding solution than traditional short arc MIG.
Note from Ed. This power source is great for a pipe root, however is
has very limited application potential outside that pipe root or thin sheet metal
weld.
The STT MIG
root will require a root gap of 1/16 to 3/16 (3/32 to 1/8 is optimum). Provide
a land of 1/16. The land is not necessary however it adds metal to the root increasing
the root weld depth. With this land, a root weld throat of of 0.125 to 0.175 will
result. The next weld can be made with the 0.045 flux cored wire.
STT
PIPE ROOT PARAMETERS: With that 0.045 1.2 mm, E70S-6 wire and argon 10 to 25%
CO2 set the parameters in the following approx. range.
Peak 320 - 360 amps,
Back Ground 40 - 60 amps,
Wire Feed 110 - 160 ipm.
Start
out with Peak 325 amps. Back Ground 45 amps.
0.045 Wire Feed set 120 - 140
ipm.
Note:
The optimum average modified STT current for the pipe root is also the same as
the optimum short circuit current for the same application. To anyone who understands
the relationship between weld current and wire feed rates, no surprise there.
Note: With the Miller PipePro equipment
it's much easier to set and adjust pipe root data.

SMAW
pipe welders, rather than resist the inevitable cost effective process changes
for pipe line welds, reach out and embrace the manual /
automated modified pulsed / short circuit transfer modes along with the flux cored
process and strive to become "manual
or automated pipe line weld technicians".
Feb 2004. Mr. Ed Craig:
I
have been welding for ten years but have never, like you say,really known the
proper weld parameter settings. What would be the optimum manual flux cored weld
parameter settings using .035 wire welding 6" schedule 180 pipe in the 6G
position on carbon steel? I have never welded with FCAW to make a root weld in
a pipe. I need to take a test on Monday and sure could use this information. I
think your book " Gas Metal Arc and Flux Cored Welding Parameters "
is the book I need to have and do plan to buy it. Thanks for your help and your
website.
Sincerely,
Larry Fritsche
Ed's
reply. I must get two letters like this every week. Two days before the welder
takes a test he suddenly realizes he will not know where to set the optimum MIG
or flux cored weld parameters for his critical pipe test and god help him if he
uses the flux core wire on the root. I provided this data to Larry.
I
WOULD ENCOURAGE ANYONE WHO MAKES A LIVING OUT OF MIG OR FLUX CORED WELDING TO
INVEST IN A PROCESS CONTROL BOOK SO THEY
CAN INVEST IN THEMSELVES.
Fronius
Twin Wire Pipe Welding
with 4 Heads 8 Weld Wires

For those of you that feel you have mastered
the single wire MIG process, or the higher deposition rate flux cored process
that offers 8 to 12 lb/hr on pipe fill pass welds, perhaps are you have the process
knowlege ready to set the 8 wires running on these four twin units that provide
an average weld deposition rate of 60 lbs/hr. This is not a difficult application,
however before you step up to this level, I would recommend my self teaching MIG
process control book.

Weld
decision makers often look to weld codes to provide practical, pipe welding advice
and recommendations. The weld reality is the weld sections of many weld codes
have been written by weld committee individuals who's strength may not be in the
weld processes under discussion.
Some of the major weld code
committees in North America are likely to have individuals that are more interested
in marketing their companies weld products than they are in writing meaningful,
logical weld spec data. Other committee members would benefit if they spent a
little more time behind a welding shield before they make their flux cored or
MIG weld comments.
50
YEARS AFTER THE INTRODUCTION OF THE "MIG PROCESS", AND 30 YEARS AFTER
THE INTRODUCTION OF FLUX CORED ELECTRODES, THE NEWLY REVISED 03/2001 "AP1
CODE 582" STATES THE FOLLOWING ABOUT MIG AND FCAW PIPE WELDING.
API.
5.2.3 Pulsed Gas Metal Arc Welding (GMAW-P. The pulsed process may be used for
any material thickness. Commentary: Whenever the welding system is changed or
the settings on existing equipment are "significantly
altered", the fabricator should verify weld properties. The extent
of verification or testing should be as agreed between the purchaser and fabricator.
PULSED
MIG AND WELD PARAMETER REALITY.
In
contrast to the traditional, simple, two weld parameter MIG or flux cored weld
processes, there are many weld parameter essential variables that can be readily
changed with the pulsed mode. The API code warns against a "SIGNIFICANT change"
in a pulsed weld settings. What is "significant" weld
parameter change?
Keep
in mind that at best the pulsed process will only provide marginal weld fusion
on vertical up welds on part thickness >6 mm. From my weld process perspective,
"a minor pulsed parameter change" can have
a significant impact on side wall weld fusion.
It's an ironic fact that
few weld decision makers or welders understand the influence of the pulsed variables,
wall thickness and weld fusion potential.
In
that MIG and flux cored weld shop or out on that pipe line, you will find the
majority of weld personnel do not fully understand the influence or the relationship
of the pulsed MIG wire feed rate, the weld speed, voltage, the pulsed frequency,
the peak and back ground current on the MIG arc plasma and resulting weld fusion
potential.
With all these pulsed variables in a pipe shop who in the shop
is going to determine what a significant weld parameter change is?
|
While on the subject of pulsed, most codes do not address "mechanized
versus manual" pulsed and traditional MIG weld inconsistencies".
When a code stipulates that a fusion sensitive weld process
like pulsed MIG is OK for any pipe thickness, the code is sending the message
that this process is recommended for both "manual and mechanized" welds.
Controlled weld speeds, fixed arc length and a controlled mechanized
weld weave have a lot to do with the success of MIG weld using any mode of weld
transfer. However you can be sure the traditional "manual weld weave inconsistency"
would make the pulsed process a poor choice for pipe fill welds in contrast to
the superior weld fusion, gas shielded all position flux cored electrodes.
ANOTHER
SECTION OF THE CODE.
API.
5.2.2 Short Circuiting Gas Metal Arc Welding (GMAW-S).
The use of GMAW-S shall be limited to
the following conditions:
a]. The short circuit process shall
not be used for branch connections or socket welds.
(What
if there is a good size root to fill in?)
b]. For vertical welding, the root pass and second pass progression for a material
of any thickness may be either uphill or "downhill".
(Have
you tried uphill with short circuit?, if so you would not recommend it.)
c]. The fill and cap pass for butt or fillet welds may be welded With this
process provided the thickness of any member does not exceed
3/8 in. (9.5 mm) and vertical welding is performed with uphill progression.
(Any short circuit welds made
uphill on parts over 3/16 >5 mm are sure to end up with inconsistent weld fusion)
d]. What about the weld gas?
The API code does not spell out the MIG gas mix that must be used with the short
circuit process or pulsed on pipe welds. Use short circuit with argon <10%
CO2 and you can weld in any position and almost guarantee lack of fusion on any
parts > 1/8 (>3 mm), (none gap welds).
e]. Why
is it that the API code will stipulate where a process can be used but will not
stipulate a simple thing like weld parameter limitations for that consumable or
process?
(Is
it possible the code committee are not aware of this data)?
Finally
the API code makes no mention of the higher energy MIG globular or spray transfer
modes, does that mean they can or cannot be used. Spray transfer can be an excellent
method for a rotated hot fill pipe pass and globular is great for ID roots or
hot pass welds.
To
repeat an important point .
IF A CODE DOES
NOT OR CANNOT PROVIDE THE COMPLETE, FUNDAMENTAL REQUIREMENTS OF A WELD PROCESS
RECOMMENDATION, THE WELD REALITY IS THAT CODE SHOULD PROVIDE NO WELD RECOMMENDATIONS
OR WELD RESTRICTIONS.
WELD CODES SHOULD PRIMARILY
BE CONCERNED THAT WELDS ARE CORRECTLY PRE-QUALIFIED AND CONCERNED WITH THE "CONDITION
OF THE FINISHED WELD PRODUCT".
2007:
I REALIZE THE IMPORTANCE OF THE PIPE AND PRESSURE VESSEL WELD CODES AND THEIR
CONTRIBUTIONS. MY POINT IS HOPEFULLY THAT THE NEXT GENERATION OF WELD CODE / SPEC
REVISIONISTS WILL SEE THAT THEIR MIG AND FLUX CORED WELD DATA RECOMMENDATIONS
DOES NOT GENERATE THE PROCESS CONFUSION THAT THEIR PREDECESSORS HAVE GENERATED.
NEED HELP WITH CODES AND THEIR INTERPRETATION? A rare individual and one
of the world's leading experts on the ASME boiler code is a gentleman named Walt
Sperko. If you need CODE expertise, contact Walt at, sperko@asme.org
|
LIKE
SOME INFO ON HOW TO PREVENT ARC BLOW?