Mechanical contractors like Coenen Mechanical LLC in Appleton, Wis., process eye-popping amounts of tube and pipe year over year. They need it on an ongoing basis to provide their customers with maintenance and repair services, but they also need it for new system installations in brownfield and greenfield facilities. When new facilities are being constructed, a mechanical contractor might need to produce thousands of pipe spools if not tens of thousands. And they need to produce them at a fast clip.
“Big jobs like a paper mill, power plant or data center are typically fast paced with tight schedules,” says Jim Forbes, lead engineer at Coenen. “Unless you have a way to really be efficient, it’s hard to compete for that work.”
And Forbes knows first-hand. Recently, the team at Coenen landed a contract for the mechanical work at a large paper mill being constructed in northern Wisconsin. To have the edge and efficiency to compete for the job, the company invested in an HGG PC900RB, a CNC machine for automated 3-D plasma pipe cutting.
When construction began, Coenen had field crews on-site, installing pipe. “As we were making it, they were putting it in,” he says.
To stay on pace, the pipe department back at the home base in Appleton produced 10,000 pipe spools in the span of 10 months. Without the PC900RB, the company might have only been halfway through the required material within that same timeframe.
“If it weren’t for that machine, there’s no way we could have hit that kind of volume within the deadline,” he says. “The benefit of the new equipment just for that one project was huge for us.”
Machine must-haves
Prior to investing in the automated plasma pipe cutting machine, the team at Coenen produced their pipe spools the traditional way. They would use a metal saw to cut the pipe to length, a grinder for bevels, and an oxyacetylene flame cutter or plasma cutter for any profile cutting.
For holes – some spools could require as many as 50 – Forbes would make a paper template for his guys to lay out each one on the horizontal pipe. They would wrap the template around the pipe, etch it out with a marker or pencil, and then cut it out with a plasma cutter.
“And then they’d have to get out the grinder to bevel it, prep it and then do the same thing again to the other side,” Forbes explains. “With the HGG system, we eliminated all those steps. For a pipe with 50-some holes in it, it would probably take two or three days for one person to do all that. On the HGG, it took about an hour.”
The PC900RB can handle pipe with up to 36 in. OD and can process a range of 3-D profile shapes while also offering the ability to chamfer and produce hole and saddle set-in connections – everything necessary for producing full pipe structures. Because weld preparations are directly included, fit-ups are precise, reducing the time it takes welders to do their jobs.
The “RB” in the name refers to the roller bed material handling and staging system, which Forbes says is “a must-have for this machine because the HGG can cut pipe so fast.” Without it, workers would have to unload those large processed pipes by hand, some of which can weigh up to a ton or more. With the roller bed, pipe is automatically rolled out of the machine onto the bed – not just for temporary storage, but also as a worktable for any minimal post-processing required.
“Right after it comes off the machine, there’s a guy waiting with a grinder for deburring and cleaning up any edges that need it,” he says. “The actual post-processing is literally just taking off some scale and maybe a little bit of gunk on the inside. Compared to how it used to be, that job is really quick now. From there, they take it to the fitters for fit-up and welding.”
A perfect union
In 1997, when Coenen got its start, the company was located in the barn on the family farm. The three founding Coenen brothers had recognized a growing need for service among the area’s paper mills and started doing field repairs and maintenance for customers. In 2008, Coenen’s current CEO and co-owner, Jeff Johnson, acquired the business, sold it and then purchased it again with partners in 2019.
Today, Coenen is a union shop that handles field work plus the full fabrication of pipe spools and components required for new installations, repairs and rebuilds. Operations have also branched into general sheet metal and structural fabrication. To perform the large range of work customers expect, the company employs union pipefitters, sheet metal workers and boilermakers within 130,000 sq. ft. of fabrication space.
“Our employees were happy to see the investment in the PC900RB,” Johnson says. “They see that we’re investing in the business, which helps us continue to be competitive and stay busy. In our market, there are always shops that are evolving. Some are getting better and growing, but some are dying. Our guys, of course, appreciate being a part of one that’s growing.”
In addition to welding, fabricating, forming, rolling and cutting stainless steel up to 2 in. and carbon steel and aluminum up to 4 in., Coenen can also fabricate pipe up to 72 in. in dia. and vessels and tanks up to 16 ft. in dia. The company also has several accreditations, including AISC (American Institute of Steel Construction) and ASME (American Society of Mechanical Engineers) for pressure vessels, power boilers, repair and alternations to press equipment, and authorization to register pressure items.
Foundation for the future
In terms of installation and training, the team at Coenen was quite happy with the process. Prior to the installation, Forbes says that some work was required on their end, but that HGG did a good job explaining what to do beforehand. After leveling out a foundation for the PC900RB outside of the shop, everything else was essentially plug and play.
“We load the PC900RB from the outside, so we basically put a big old hole in the side of our building,” he says. “The total length of the machine is about 90 ft. with 50 ft. of that outside where we load the pipe, which then gets conveyed inside. The outside part is where we had uneven ground and had to put some footings in to level the bed.”
Other installation prerequisites involved preparing for the air, gas, argon and whatever cutting gases the company needed to pipe in. The Coenen team also had to establish the electrical foundation and data cables because the HGG is a fully networked machine.
“We save our programs on the network, and the machine pulls them right off it,” he says. “That’s basically all we needed to do beforehand so that everything would go super smooth.”
Once the machine was installed, which took about one week, HGG conducted one week of training with Coenen’s operators. Forbes says that two operators were initially trained and that the knowledge transfer to additional staff has been smooth.
“We’re a union shop, so our pre-apprentices and apprentices typically get trained on this type of work,” he says. “Since the HGG was installed about a year and a half ago, we’re on our third generation of operators. The HGG is actually where our apprentices start. They learn the machine and run it for nine or 10 months, depending on how their apprenticeships go. Then, they get their apprenticeship and move on to schooling and learning the pipe trades.”
Overall, the nature of the union shop has helped Coenen avoid some of the labor issues that the greater manufacturing industry has had to endure. The team there has excelled at job recruitment, hiring the most apprentices in the past two years since the company’s founding. With a steady stream of employees as well as new equipment investments, like the HGG, the future for Coenen is bright.
“The business is taking off in all kinds of directions,” Forbes says. “The investment in the HGG is putting us in line with some of the bigger players, but we’re also looking forward to the installation of new project management software specifically designed around piping.
“We’re going all-digital throughout the whole pipe shop,” he adds. “We’re putting computers in every fitter’s and welder’s bay, so that they can work right off of the 3-D models. It’s going to streamline a lot of stuff. It’s pretty exciting.”
