Annual construction spending in the U.S. grew for six consecutive years, from 2012 to 2017, according to data from the Department of Commerce. In each of those six years, spending on power construction projects topped all other segments in nonresidential construction, making it a major driver of industry trends.
With U.S. construction spending hitting a seasonally adjusted annual rate of $1.32 trillion in June 2018, staying on schedule and within budget in this competitive and demanding environment is critical for contractors.
The processes and technologies used in the welding process may seem like a small part of the overall picture, but they can play a significant role in saving time and money on construction jobsites.
Finding ways to save time in the welding operation is especially critical as the trades industries deal with a skilled labor shortage and many companies struggle to find enough skilled welders to meet demands.
Kiewit Power Constructors Co. has found success with a switch to more productive welding processes for some applications on combined-cycle power plant projects. Since making a change to advanced wire processes, the results for Kiewit include improved productivity and reduced costs.
Work on combined-cycle power plant contracts continues to be strong for Kiewit Power Constructors, which performs power plant construction as an individual entity under the Kiewit umbrella.
In August 2018, the company had six combined-cycle power plant projects actively under construction, with another three projects awarded and expected to begin soon. While combined-cycle natural-gas-fired power plants are its specialty, the company also bids and completes some power distribution work.
Combined-cycle power plants use both gas and steam turbines together to produce up to 50% more electricity from the same fuel compared to traditional simple-cycle plants. Large components of combined-cycle power plants are typically modular in design and involve mostly large- and small-bore pipe welding of carbon steels, low-chrome alloys and stainless steels.
For Kiewit, construction of a combined-cycle power plant can span two to three years and the welding component can take about half of that time.
A single project may require 30 or 40 full-time welders—or perhaps as many as 100 welders depending on the scope. Because utility companies or plant owners often have a specific deadline for when a plant must begin providing power, when project deadlines are missed it can result in very high operational costs for utilities or plant owners.
Tailoring welding methods, specifications and technologies for these types of plants has helped the company optimize the construction process.
Kiewit prides itself on finishing projects on time, according to Justin Morse, district welding engineer for Kiewit Power Constructors. While the skilled labor shortage hasn’t impacted the company’s ability to finish jobs on schedule for customers, it has increased labor costs as the company pays more to pull in the right talent to meet the necessary welding requirements, according to Morse. “The skilled labor shortage continues to be an issue,” he said.
The welding industry as a whole faces a growing shortage of skilled welders, due to a lack of incoming welders and the retirement wave of experienced workers.
To help address this challenge—and still meet demanding project deadlines—Kiewit implemented more productive welding processes and technologies and has tailored its training program for new welders.
The construction industry can be ever-changing—with the market’s ups and downs driving bidding, contracts, projects and timelines. To meet the higher market spending on power plant construction in recent years, Kiewit changed its welding processes. This move to more productive processes also helped the company maximize the available skilled labor pool.
In welding applications where the company previously TIG welded the root pass on chrome alloys, including P91 pipe, Kiewit converted to advanced wire welding, using the Regulated Metal Deposition (RMD) process from Miller Electric Mfg. LLC. This modified short-circuit MIG process can be used without a purge, saving time. For the remaining passes, Kiewit uses flux-cored arc welding (FCAW) instead of stick.
“RMD and FCAW are 100 percent the go-to processes for large-bore welding on all materials for the company,” Morse said. “We see significant productivity gains utilizing these processes, along with consistently low weld reject rates that are below the industry average.”
The conversion was possible because the RMD process provides the ability to put down a thicker root pass, eliminating the need for a hot pass and supporting the heat input of pulsed MIG or flux-cored welding for the fill and cap passes. These wire processes also offer much greater productivity on the jobsite, with travel speeds three to four times those of TIG and stick welding.
In addition, wire processes are often easier to learn and use, so Kiewit can quickly train and qualify skilled welders for power plant construction projects. In the RMD process, the power source anticipates and controls the short circuit and reduces the welding current to create a consistent metal transfer.
Precisely controlled metal transfer provides uniform droplet deposition, making it easier for the welder to control the puddle. Advanced welding processes such as pulsed MIG or modified short-circuit MIG are also more forgiving to variations in stickout. This delivers a calm, stable arc that’s easier for welders to control.
The process conversion saves labor-related costs, helping Kiewit address the challenges of the skilled welder shortage by improving productivity and efficiency in the welding operation. And because the advanced wire processes help less experienced welders complete high-quality welds more consistently, it saves time and money in rework and scrap for the company.
In addition to using more productive welding processes, Kiewit also relies on other welding technologies and innovations that deliver benefits for productivity, efficiency, quality, and welder safety on the jobsite.
Welding technology that offers complete control of parameters at the weld joint allows welders to make adjustments quickly and easily—without leaving their work. In addition to saving operator time and improving safety, this also eliminates the need to make do with less-than-optimal welding parameters, since the welder can easily make changes as necessary.
Compare that to outdated welding equipment that doesn’t provide remote control of parameters at the weld joint. This forces welders to make numerous walks back and forth to the power source to make changes—wasting hundreds of productive work hours and thousands of dollars in profit each year.
Some newer remote welding technologies also provide these capabilities without the need for a special control cable, which eliminates the hassles and expense associated with special cables and reduces jobsite clutter.
The change in welding processes to better suit project needs also led Kiewit Power Constructors to adjust welder training. While more contractors are making the switch to wire processes, stick and TIG have traditionally been used on many jobsites.
Kiewit partners with local pipefitter and boilermaker unions across the U.S. and Canada on many of its power plant projects to ensure welders are trained and qualified in the wire processes being used.
“Typically, this involves having a welding trainer work with the instructors at the local union prior to the start of a job so they can adequately train and prepare their membership for the nature of our work,” Morse said.
It’s been a successful training model for the company, and one that is repeatable with union partners in many locations. The partnerships have resulted in welding testing and training programs specific to the requirements Kiewit uses for power plant projects. The UA 101 and UA 102 Kiewit-specific weld tests help get welders trained and qualified quickly for specific pipe welding processes and procedures.
Meeting project timelines is critical in the demanding, seasonally driven construction industry. A conversion to more productive welding processes and technologies has helped Kiewit Power Constructors address this—as well as the challenges posed by a shortage in skilled labor.
Advanced wire processes make it easier for less experienced welders to complete high-quality welds. These processes also improve productivity and efficiency without sacrificing weld quality.Kiewit saw a benefit to the bottom line with more productive welding solutions—helping them stay competitive and meet project deadlines for customers.
Jeff Robedeaux is CWI/CWE welding sales specialist of pipe welding products for Miller Electric Mfg. LLC.