Lincoln Electric FCAW-G manual An Overview of the Pipe Installation Process

W E L D I N G C O N S U M A B L E S

SUCCESS

Flux-Cored (FCAW-G) Welding		2/4
Welding on Pipe	Cheyenne Plains Pipeline

“We chose the Lincoln Pipeliner G80M wire for this project for a number of reasons. First, it met the mechanical requirements of the job and also offered a crisper arc,” said Bratcher. “In addition, we felt that the Lincoln product flowed better and was more suitable for outdoor use.”

An Overview of the Pipe

Installation Process

More than 140,000 tons of pipe and 25,000 individual sections were used to complete this project. Each section of pipe is 78-feet long and per industry standards, was buried at least 30 inches below the ground through a trenching process.

Much like an assembly line where each worker is responsible for a certain por- tion of the job, construction crews in each spread followed after each other along the length of the pipe to complete specialized tasks. Crews at the front staked the area and prepared the right- of-way. Those following behind aligned the pipe, welded and inspected the pipe

and then lowered it into the trench. Finally, the construction crews at the rear were responsible for conducting hydrostatic pressure testing, backfilling the trench and restoring the land as close as possible to its original condi- tion.

Welding Connection Points and Road Crossings

After a lengthy process of evaluating solid and flux-cored electrodes for the job, U.S. Pipeline, Inc. selected a .045- inch diameter Pipeliner G80M wire as the consumable of choice for the vertical up welding of the pipe tie-in fill and cap passes. The Cheyenne Plains Pipeline Project marked the first time this new consumable was used in the field and for many of the pipeline con- tractors, it was also the first time they had made the switch from a traditional Stick process to complete the tie-ins for the job.

“We chose the Lincoln Pipeliner G80M wire for this project for a number of reasons. First, it met the mechanical requirements of the job and also offered a crisper arc,” said Dana Bratcher, Welding Foreman, U.S. Pipeline, Inc. “In addition, we felt that the Lincoln product flowed better and was more durable for outdoor use. We also were attracted to the fact that the pipe supplied from the manufacturer was welded using a Lincoln consumable.”

This electrode, specifically designed for pipeline welding, is easier for the operator to use and provides a smooth arc, lower spatter levels and less frequent

clogging of gun nozzles when compared to other flux-cored wire electrodes.

All tie-in welds were performed manually because of the special- ized skills needed to handle fit-up issues between the thinner main- line pipe and thicker tie-ins. Each manual welding team consists of two welders, one on each side of the pipe performing one-half of the welding pass – root, hot, fill

and cap. Each welder also had an assistant who performed tasks such as preheating the joints, setting the clamp to align the two lengths of pipe, setting up the welding equipment and complet- ing the finish wire brushing on the joint.

Every tie-in weld was inspected with a radiographic process and throughout the job the weld quality had been excel- lent. “We had a low repair rate with the Lincoln wire. It was consistent and worked wonderfully,” noted Bratcher. “Our welding operators liked the fact that they were able to see how the puddle flowed.”

The use of Pipeliner G80M wire to weld the spiral seam pipe’s fill and cap pass- es provided significantly increased productivity and high quality welds. “The wire is about three to five times faster than stick welding,” said Ray Edwards, an independent pipeline welder from the Pipeliners Union 798 and one of the welders on Spread Two of the project. “The same length of weld bead that would take up to five minutes with stick welding is now taking me about one minute.”

In addition, Lincoln’s Shield-Arc 70+ stick electrode was used to complete the tack welds and vertical down root pass on these tie-ins. This rod was cho- sen for its ability to accomplish the out- of-position welding required for this job.

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