When weld prep matters

Appellation Pre-Fab uses the Dually® wheels as the first step in material preparation to knock off rust, slag, or other contaminants. They then bevel the pipe edges and, using the flap disc, grind down the bevel to a knife edge to make it clean and smooth as glass and remove all impurities from the surface immediately before welding. (Photo courtesy of Appellation Pre-Fab, Mountoursville, Pa.)

Appellation Pre-Fab of Montoursville, Pa., has absolutely no room to make sacrifices on material cleanliness. The welding and fabrication company that specializes in large-diameter pipes welds anything from 1- to 60-in.-diameter pipe with thicknesses from 1⁄10 in. to 1½ in. for many of the major pipeline owners throughout the U.S.

Plant Manager Brian Carey said 100 percent of the welds that are laid are nondestructively tested (NDT) with X-ray or magnetic particle to ensure they pass strict welding codes. The welders themselves also must undergo an intense testing regimen.

As most welders know, the weld itself is only as good as the equipment, the filler material, and, in some cases, the material prep process. In Appellation’s case, said Carey, material preparation and cleanliness are of the utmost importance.

“One of the most important factors in having a good weld is material cleaning and grinding. It’s probably the most important process outside of the actual welding and having a good welder. If the prep guy doesn’t do a good job, and if the welder doesn’t notice it because he’s busy doing his own job, that reflects poorly on the welder,” he said.

The Problem

The material preparation process must be perfect, but there was a time at Appellation when it wasn’t. In fact, material prep was a downright struggle. Grinding wheels wore out quickly, which became expensive and time-consuming for those who were constantly changing out wheels.

The frequent wheel changeouts also made the entire shop floor less productive.

“Every time the pipe fitter preps pipe and has to change his grinding wheel, he stops, goes over to the tool crib to get a wheel, and either talks to his buddy on the way back or goes to the bathroom or gets a drink. Switching out wheels became more than just switching wheels,” Carey added.

There was also the issue of safety, said Westley Smith, welding engineer and project manager.

“Wire wheels in particular are pretty dangerous tools. I’d say they are in the top two most dangerous pieces you can attach to the end of a grinder. If they catch you and you’re not properly protected, it can end pretty badly,” Smith said.

This was a concern because if the company’s incident rate was too high, Smith said it would be placed on a no-bid list. They could not afford preventable accidents to pop up because of poor material prep equipment.

The Solution

After researching grinding wheels available in the marketplace, Appellation decided on the Dually® wire wheels and the Tiger X flap discs from Weiler Abrasives Group. They use the wire wheels as the first step in material preparation to knock off rust, slag, or other contaminants. They then bevel the pipe edges and, using the flap disc, grind down the bevel to a knife edge to make it clean and smooth as glass and remove all impurities from the surface immediately before welding.

What they found was the wire wheels provided a level of safety that they weren’t getting with the other wire wheels they had used previously.

“No matter how a wheel is designed, it’s going to wear a certain way. Our old-school welders would just flip the wheel to reuse it when it became too worn, which would bring the wheel really close to their hand. With the Dually, it keeps the wheel away from their hand and makes it safe. Every time our guys flip the wheel, it’s like putting on a new wheel. We are safer and much more productive,” Carey said.

They have found the flap discs last longer and are more efficient at removing the contaminants. That helps keep the operators on task longer, and most important, it helps the welders lay a weld that passes inspection. Safe welders paired with quality welds that pass inspection means Appellation can continue bidding for and winning large critical pipeline projects. In fact, they have had no recordable incidences in the last two years. Those things trump the cost of consumables, Smith said.

“When you’re paying as much as we do for our labor, the cost of grinding consumables is pretty insignificant in the grand scheme of things. It just doesn’t make sense for our employees to use a grinding disc that saves us 10 percent in cost but is 30 percent less effective and also less safe.”

Appellation Pre-Fab, 570-601-4765, www.appellationprefab.com

Weiler Corp., 800-835-9999, www.weilerabrasives.com