Energy delivery has become one of the world’s fastest growing industries with thousands of miles of oil and gas pipeline planned or under construction in countries such as the United States, Russia, India, China and Brazil. Every mile of pipeline requires welding – both for pipeline construction and the fabrication of the equipment required to maintain and repair pipelines.
Based in Tulsa, Okla., TD Williamson Inc. fabricates the hot tapping and plugging equipment which allows pipeline repair and maintenance to be done without having to stop the flow of oil or gas. This includes both above-ground and underground pipelines, which operate under high pressure, as well as offshore pipelines, where a line can typically run 1,000 feet or deeper underwater.
The company recognized a substantial increase in orders due to the unprecedented growth of the industry, and rather than rush into costly expansion, its engineers decided to reevaluate the overall welding operations.
One of the company’s main production concerns was pipeline fittings, made in 4-inch, 6-inch and 8-inch diameters. They are used to attach the company’s hot tapping and plugging equipment to pipelines for construction, maintenance and other applications.
“We needed to dramatically decrease the time it took to produce the fittings,” said Mike Phillips, TD Williamson manufacturing engineer. “It was taking 30 minutes to manually weld the tacks and the root, hot and cap passes, in addition to the time spent grinding in between passes.”
So the company began investigating the benefits of automation.
Move to Automated System
After extensive review, the decision was made to convert the company’s manual welding operations to an automated process. The change decreased fabrication time by 87 percent, but the firm needed a new welding process that would not only achieve the new fast-paced production schedule, but preserve consistency and quality.
Working with team members from Lincoln Tulsa and its Cleveland headquarters and AMET (a manufacturer of automated welding systems), TD Williamson installed its automated system complete with Lincoln’s Power Wave® 455M and Power Feed® 10R wire feeder integrated with an AMET automated welding system.
The integrated AMET/Lincoln system is designed as an automated, electronically controlled welding system for large production welding where consistency and repeatability are important. The system also uses fixtures and positioning equipment as part of the weld process.
The Power Wave® 455M is designed for welding thicker materials in robotics, hard automation and semiautomatic applications, where heat input control, minimal distortion and reduced spatter are needed. The Power Wave® 455M features Lincoln Electric’s Waveform Control Technology™ which allows the user to better match the arc with the welding task, and it quickly and easily adapts to a wide range of welding material specs, weld positions and strength requirements – all of which were considerations for TD Williamson.
“The welds on our equipment and fittings are subjected to tremendous strain and pressure, as pipeline systems have become more complex with higher operating pressures and temperatures, larger pipe diameters and more volatile products,” Phillips said. “Waveform Control Technology™ allowed us to meet these requirements, increase the amount of control we had on the welding procedure, and get parts done faster”
Productivity Increased with Elimination of Weld Passes
The Power Wave® 455M allowed the company to use Lincoln’s pulsed MIG waveforms. Switching to this process allowed TD Williamson to eliminate issues the company faced with getting the root to tie-in properly. The Power Wave® 455M also allowed for better control and decreased spatter. The company is able to maintain quality, productivity and more than adequate penetration on thicker carbon steel and perform the root and fill passes much faster.
“At Lincoln’s recommendation, we switched from .035 to .045 diameter Ultracore® and SuperArc® wire, which eliminated our problem with the wire wanting to shoot through the pipe, and it allowed our operators to perform less weld passes,” Phillips said. “This was just one more thing which contributed to our increase in productivity. We reduced the overall cost by purchasing less wire as well as decreasing the labor needed per project.”
Another contributing factor to the companies increase in productivity was its elimination of four welding passes.
“Before the new system, we were making six passes. We were easily able to reduce that to two, which has made a huge difference in project throughput,” Phillips added.
The pipeline fittings enter the plant as flat steel plates. They are positioned in a 1,800 F degree oven and pressed in a hydraulic press. They are then sand blasted and positioned on the automated weld table using both fixturing and positioning equipment, where the flange is MIG welded onto the sleeve that was previously created. The fittings are then cleaned, fully assembled, numbered and painted.
The last step includes X-ray testing each weld to ensure its integrity. With the new Power Wave® and AMET system, TD Williamson has experienced a 100-percent pass rate for all of its parts. In the past, the pass rate had hovered between 95 to 98 percent.
Before installing the new welding system, TD Williamson performed nearly all welds manually. The sleeve was mounted to a fixture, and the flange was added with spacers tacked by hand. The main weld was put in and then the spacers were removed. The new hard automated system has eliminated the need for the tacking and the fit up. It has also eliminated the need to grind out the root weld.
87-Percent Decrease in Manufacturing Time
“What used to take eight weeks to run through our plant can now be done in 48 hours,” Phillips states. “We’re able to work in real-time, meeting current demand as orders come in – whereas we previously had to guess what our customers would need two months out and having trouble meeting orders if we hadn’t guessed correctly.”
With this 87-percent decrease in overall manufacturing time, the company has saved significantly on labor costs and increased the overall quality of the welds on the fittings. This translates into better weld penetration, more up time for the equipment, less required rework and faster turnaround time to deliver the fittings to the jobsite.
Phillips added that much of the company’s success with the new system is due to Lincoln Electric and AMET’s willingness to spend time on site at the Tulsa plant, work through installation and start-up with the company’s team, and always be on call when needed.
"Our productivity is up considerably. We’re producing higher quality welded parts and more of them,” Phillips said. “This translates into faster turnaround time to meet customer demand, and in our business, nothing is more critical than this. The AMET/Lincoln Electric system gives us a competitive advantage."