Reducing wasted shielding gases can provide savings on large and small jobs.

Eliminating waste on the factory floor is a key principle of lean management and, for welding one of the biggest sources of waste is shielding gas.

While welders are aware of the amount of shielding gas they waste, especially at start-up, management often overlooks this source of waste. However, when the cost of that shielding gas is calculated, many shops find that it is a considerable drain on profit.

While gas suppliers don’t have much incentive to help customers save wasted gas, manufacturers who do a lot of welding and who implement lean manufacturing philosophies do.

There have been many attempts to reduce shielding gas waste over the years, and those attempts have included the use of restrictors. However, the dilemma with a restrictor is that it can stop the surge, but gases are still wasted. On the other hand, some extra gas is needed at the start of the weld.

One of the more successful methods of reducing the waste of shielding gases to come along over the past several years was a product called Gas Saver System from WA Technology. Gerald D. Uttrachi, president of WA Trechnology and the 2007 president of the AWS, is its inventor.

“There’s a lack of understanding that there is an issue when it comes shielding gas waste. The amount of waste is really frustrating, sometimes exceeding five times the hose volume, but it’s easy to analyze if you test correctly,” Uttrachi said.

Uttrachi recommends putting a full cylinder of gas on an application and a full cylinder of wire, then comparing the amount of gas used to amount of wire consumed, to test the amount of waste analytically.

“It won’t interfere with anything that causes problems for the welder,” Uttrachi said. One of WA Technology’s first customers was Double A Body Builders, a manufacturer of truck boxes based in Pamplico, S.C.

Double A Body Builders has 50 MIG welders that use an argon/CO2 shielding gas mixture to keep spatter to a minimum and to produce highquality, visually attractive welds.

The company’s MIG wire feeders were located about 30 feet from a shielding gas pipe system that is used throughout the shop. In analyzing its shielding gas use, Double A Body Builders found it used twice as much wire per cylinder of gas with WA Technology’s Gas Saver System.

Uttrachi said that analyses that he has done show that average users consume approximately 30 cu ft gas per lb of welding wire, when they only need 5 cu ft per lb of wire, but it averages from 3 cu ft to 7 cu ft.

One of the primary sources of shielding gas waste is the start-up surge. Not only does it waste gas, but it sucks moisture-laden air into the shielding gas stream because the initial flow rates are so high, Uttrachi said.

“The surge is a significant factor,” that is difficult to measure, he said.

As an example, Uttrachi cited the following:

A truck box manufacturer that welds doors with short welds was able to weld 236 doors with one gas cylinder. After adopting Uttrachi’s Gas Saver System, the manufacturer welded 632 doors with the same type of welds with one gas cylinder, a 63 percent savings. However, Uttrachi said that savings of 40 percent to 50 percent of gas use is typical.

The patented gas saving systems uses a gas delivery hose with a small inner diameter combined with a surge flow control orifice. Uttrachi said that typically reduces the surge of shielding gas at the start of a weld by more than 80 percent.

“A 1/8 in. MIG gas hose 50 ft. long will flow more than sufficient gas with flowgauge regulators, typical pipeline pressures and most flowmeters. Tests show that our Gas Saver System, which utilizes a 1/8 in ID hose, even with hose that is 100 ft long, creates a pressure drop of only 12 psi at normal MIG gas flow rates,” Uttraci said. Because flowgauge regulators and pipeline supplies typically are 50 psi or higher, even that pressure drop provides the 2:1 absolute gas pressure ratio at the flow control that is needed to maintain automatic flow compensation, he added. With hoses that are 50 ft. or less, there is sufficient pressure to perform adequately even with a gas delivery systems at pressures of 25 psi, he noted.

Besides wasting gases, the initial surge of shielding gas also can create porosity in the weld.

Uttrachi said he worked with a welder who knew the surge was there, and was getting 50 percent to 60 percent rejects.

“He used to hold the torch really far away, but his surge lasted for more than 5 sec, and there was no way he could hold the torch far away for that long. Eliminating the surge improved quality,” Uttrachi said, adding that improved quality is a central reason to find a way to reduce the start-up surge in shielding gases.

Uttrachi has three U.S. and Canadian patents on his gas saving products. The small diameter hose was patented in August 2003, and he received two more patents in 2006, on more complex products such as a higher pressure regulator which is just being introduced and is licensed to ESAB.

“This product more expensive but will work on any length hose. The other one works up to about 50 ft,” Uttrachi said.

Uttrachi added that the use of a smaller ID hose seems so simple that he finds people reluctant to believe that it will work, yet it’s a cost effective solution to a costly problem.

“It’s not much more expensive than a standard hose but the payback is instantaneous,” he said.