New Engine-Driven Welder Generators Provide Michels with Improved Arc Performance, Reduced Fuel Use on Dominion’s Appalachian Gateway Project
New diesel engine-driven units reduce fuel use by as much as 30 percent, improve weld quality with difficult electrodes, and reduce weight on trucks by as much as 500 pounds.
The 55-mile stretch of Dominion’s Appalachian Gateway Project currently being constructed through Western Pennsylvania will help supply Mid-Atlantic and Northeastern states with a much-needed source of natural gas. Brownsville, Wisconsin-based Michels Pipeline Construction is contracted to build the 24-inch X70 transmission pipeline, scheduled to go into operation in September of 2012.
As work began in August 2011, Michels was faced with a number of challenges: a varying and treacherous terrain, narrow stretches of right-of-way that bordered residential areas, and a wet fall that consistently muddied the site. The company used a combination of truck-mounted welders and welding sleds to weld the pipe, depending on the weather conditions and the width of the right-of-way.
The project marked one of the most concentrated uses to date of Miller’s new Big Blue® 350 PipePro® diesel engine-driven welder generators, designed specifically for transmission pipeline construction. Michels rented a number of units through the Miller Rental program for the sleds and many of the Local 798 pipeline welders, hired by Michels, have outfitted their trucks with the new machine. Engine-driven welding technology has evolved to the point where machines are providing greater functionality and performance in a smaller, more fuel-efficient package.
“It’s a crisp arc that will weld a pipe and it bonds real quick,” says Floyd East, a welder with Michels. “It’s quieter, smoother, lighter, has more power. It’s 325 amps at 100 percent duty cycle, and it only weighs 1,018 pounds versus (other machines) that are 1,400 pounds and 200-amp duty cycle, and they don’t have wire features or Lift-Arc TIG. There’s a whole lot more options on these, including 220- and 110-plug-ins. It’s cheaper on fuel. I’ve got to weigh all that. It’s the only one to have.”
Machine Performance and Arc Quality Overcomes Difficult Electrodes
Wall thickness of the X70 pipe used in this project varies depending on where the pipe is being laid. The mainline consists of both .375- and .438-inch wall thicknesses, while residential areas and road crossings feature .500-inch-thick pipe. Each joint is welded in three steps, with an assembly line-like procession of trucks and machines making its way down the pipe. The first crew runs a root pass, the second crew comes in welding a hot pass, and a third crew then comes in and welds fillers and a cap pass. Each pass is completed by two welders who simultaneously weld from the top of the pipe to the bottom of the pipe directly opposite of one another.
This entire stretch of the pipeline is being welded with the cellulosic Stick electrode process. E6010 electrodes are being used on the root pass, and E8010-G electrodes are used for all fill and cap passes. While these cellulosic electrodes are specified for this job, they can create an erratic arc and large amounts of spatter depending on how they are used. Welders on this project report that the Big Blue 350 PipePro has helped reduce those problems through advanced arc controls. The machine’s Hot Start™ function provides positive stick electrode starts, while its Adjustable Arc Control automatically adjusts DIG, which determines how much amperage varies with arc length.
“With this new Miller, I’ve got it down to where it just sits there and sizzles real nice,” says East. “I’ve been welding with it since this job started and I finally had to weld with (another machine) and it was a night and day difference. Spatter was flying off, and it worked me to death compared to welding with the Miller. The Miller tied in to the edge much quicker, it’s got the good arc forcing it in there, and it melts and bonds quickly. Even with these difficult rods we have today, you can set it to where it will do well.”
“It’s more controllable, more stable,” says Tim Gintz, welder foreman, Michels Corporation, “it’s a tighter, more concentrated puddle. It allows you to put (the bead) where you want it. Whereas (other machines) are more buttery compared to the stiff arc that Miller makes. It cuts through the metal better (than older machines) and it flows much better—you don’t have to wait on it. ”
Engine-driven welding generators of the past have also been notorious for being affected by temperature and other extreme conditions, often presenting varying arc characteristics throughout the day or week. The design of the Big Blue 350 PipePro, combined with the fact that it is rated at 104 degrees Fahrenheit, helps ensure machine performance no matter the time of day or weather conditions. Dale Kennedy, one of Michels’ welders on this project, reports that the machine has been extremely consistent.
“It’s very consistent from the time you start in the morning to the afternoon in terms of amperage and voltage,” says Kennedy. “The arc performance is consistent all day long.”
The machine also goes through rigorous testing for the extreme conditions found in pipeline applications: airborne dust and sand, humidity and corrosion, temperature extremes, jobsite abuse and continuous heavy operation. East, who has had his machine for more than a year, reports no problems to date and that the quality of the machine’s performance has helped ensure weld quality.
“I haven’t had the first problem with the machine,” says East. “Zero. This is our livelihood and bad news travels all over the world real quick. You start having repairs out here and it will be all over the place. You don’t want that on your name, you want to be known as a good welder.”
Fuel Savings Help Reduce Operating Costs
One of the biggest factors for an independent rig owner or a pipeline contractor when specifying a piece of equipment is fuel costs. When Miller designed the new Big Blue 350 PipePro, it incorporated a new EPA Tier 4 Compliant Mitsubishi S4L2 4-cylinder engine that operates at 1,850 RPM instead of 3,600 RPM. This helps reduce fuel use by as much as 50 percent compared to other machines on the market and by 20 percent compared to Miller’s previous machine in this size class. When matched head-to-head, the fuel savings are evident.
“We’re working on sleds, and the other machine uses 2-1/2 more gallons of fuel per day (compared to the new Miller machines),” says Kennedy. “We’ve measured it several times while working them hard. The Miller is more fuel friendly.”
“About a month or so after I got (the Big Blue 350 PipePro), we went on a sled making tie-ins,” says East, “so they put my machine on the sled and (another welder’s) on the sled. The fuel truck would come every so often and fill us up. He ran out of fuel one day and mine said it was empty, too. He says ‘at least we know they’re burning about the same amount’, but what he didn’t know was that I’ve got an 11-gallon tank and he’s got a 16-gallon tank. So you’re looking at a third less (fuel use with the Big Blue 350 Pipe Pro).
“I save on average $6-8 each day in fuel, depending on how hooked up I am. You add it up throughout the year, it’s a lot of money.”
If East works an average of 260 days in a year, that adds up to between $1,560 and $2,080 in fuel savings annually. It also reduces hassles on site because it reduces the amount of trips a fuel truck has to make to fill up a machine (contractors are not allowed to keep diesel cans on their trucks). The lower RPM also provides another crucial benefit: it lowers sound levels by about 40 percent.
“Noise of any kind is detrimental,” says Gintz. “It’s a safety factor. (With this machine) people can hear you even though you have a hood down.”
“It makes it more comfortable to work, you can concentrate more on your work, you can talk to your helper,” says East. “The day is more pleasant to me. The older I get, the quieter I like it. You don’t have to scream at your helper when you want him to do something. It’s just quiet.”
Reduced Weight Helps with Truck Regulations, Performance
Pipeline welders must fit every tool they need for a job onto their trucks. The most common trucks you’ll see pipeliners use for rigs today feature dual wheel rear-axles, which are typically necessary to carry that weight. They also invite more scrutiny from DOT authorities in terms of weight limits, which have driven some contractors to switch to three-quarter ton trucks. Considerably smaller machines like the Big Blue 350 PipePro—which weighs in at only 1,018 pounds—have helped pipeline contractors reduce weight and better optimize space on their trucks with a smaller footprint.
“(Compared to other machines) it’s 3-, 4- or 500 pounds lighter,” says East. “That’s like taking a full set of bottles off your truck. You take that off your truck and you can tell a world of difference in the suspension on your truck. It just rides better, handles better and everything.”
“It’s just lighter,” adds Gintz. “You can tell the difference on your ride, on fuel economy (of the truck) and on travelling.”
Wireless Remotes Prove Easier, More Reliable than Corded Models
Every pipeline welder has a helper, and that helper is typically anchored to a corded remote box while the welder is making a weld. A key part of the helper’s job is remote management, which includes a lot of time spent rolling and unrolling cord.
The Big Blue 350 PipePro is compatible with Miller’s new wireless remote technology, which eliminates the hassles and potential malfunctions associated with corded remotes, and features a digital display that lets the helper know exactly what the machine is set at. With a range of 300 feet from the machine, wireless remotes provide welders and their helpers with the most efficient way to dial the machine in accurately and ensure quality at the point of use.
“I don’t have to carry around that big lunch box (that holds the corded remote),” says Jason Delapaz, a welding helper with Michels on this project. “I don’t have to drag all that stuff around. You just clip that remote on your hip and go. It’s a lot easier and you can read it a lot better, too, compared to a (rheostat) dial where you have to guess where you are. Compared to other helpers, you could be out there doing your job and he’s still unrolling his stuff.”
“It’s responsive right there when you need it and you’re not dragging a cord,” says Gintz. “You don’t have malfunction problems or spend time troubleshooting a problem if you have one in the cord. The remote is right there and you can keep it in your pocket until the next weld. It’s very, very helpful.”
“I had a helper last year and we were welding over a pond,” says East. “He dropped it in there. I asked him to turn it down, and he was afraid to tell me he dropped it in. We fished it out of about three feet of water, put new batteries in and it’s been working ever since, no problems.”
Wire Capabilities Set Welders Up for the Future
The machine offers a number of other key benefits. 12,000 watts of peak single-phase power (10,000 watts continuous) provides more than enough power to run jobsite tools such as grinders. Meter maintenance displays help keep track of, and simplify, maintenance. A standard LINE-X® cover provides superior impact, corrosion and abrasion protection. And as pipelines throughout North America begin switching to high-strength steels and move away from cellulosic Stick electrodes, contractors will be expected to utilize low hydrogen processes. Flux Cored welding is the most viable option and the Big Blue 350 Pipe Welding System is optimized for welding these wires, using Miller’s SuitCase® X-TREME™ 8HD wire feeders. This means pipeline welders will be fully armed with technology to handle any welding application found in transmission pipeline construction today and in the foreseeable future.
“It’s just been a super product,” says Gintz. “People are buying them because they know that Miller stands behind their product. They’re the type of people who help you get it done, and I believe in it.”