In an industry where every penny counts, finding ways to reduce costs is essential. One of the areas with the most opportunities involves the use of shielding gas, which is typically one of the largest expenditures that companies make to support their welding operations. Fortunately, there are low-cost solutions that maximize the value these companies get out of their gas purchases. Many of those solutions are found in investing in the right equipment.
While it may seem counterintuitive on the surface, a small investment into the proper gas equipment can easily provide significant gas savings. As a first step, take an analytical look at each specific welding process and determine benchmarks. Determine the precise amount of shielding gas needed to provide an adequate weld. In doing so, a company can identify where gas is being wasted.
When searching for cost savings, those who set benchmarks in gas usage will most likely discover that their processes are extremely wasteful. After determining that there is waste within the process, the next step is pinpointing where the waste is so that it can be eliminated.
Reducing gas surge can lead to significant cost savings. These surges occur every time the solenoid is activated, or, more precisely, at every trigger pull on the welding torch. Most flow control equipment used with shielding gas, whether from a cylinder or a pipeline, is designed to operate at pressures of about 20 to 30 lbs. per sq. in. gauge (psig), while applications using pure CO2 may operate at pressures up to 50 psig. This means that every time a welder squeezes the trigger, the upstream pressure of 20 to 30 or even 50 psig exits the nozzle, wasting a large amount of gas when the trigger is pulled.
Fortunately, there are many gassaving devices on the market. These devices include, but are not limited to, gas guard regulators, point-of-use orifices, lower pressure flowmeters and even surge reducing hoses. These flow control accessories set a limit so that excessive flow rates that make the gas turbulent, thereby drawing oxides and nitrides into the weld, cannot be used.
While these devices have been around for more than two decades, they rarely receive sufficient attention until market conditions create the need for companies to seek them out. Therefore, a great deal of misunderstanding surrounds these products.
Some of the more popular devices that can be added to the wire feeder to control gas surge include gassaving regulators and point-of-use orifice fittings. Welding professionals, however, should be wary of in-line restricted orifices as shielding gas savers. These devices, if not installed at the correct point in the gas stream, will not have any effect in eliminating gas surge. The most effective way is to introduce a pressure-regulating device into the gas system.
Point of use orifice fittings can work well and are generally a low-cost solution. However, to work properly, the orifice fittings must be installed precisely in front of the solenoid valve. Anywhere else in the gas stream, like back at the regulator or the flow meter, will not work and the surge problem will remain.
In contrast, an inert gas guard can be placed anywhere in the gas stream, taking that high upstream pressure and regulating it down to eliminate the surge. When the solenoid valve opens, there won’t be the usual high pressure upstream, so instead of 50 psig, there is only roughly 10 psig. That type of reduction can easily result in significant annual gas savings.
Typically, welding equipment is designed to operate at relatively high line pressures, such as 20, 30 or 50 lbs./in.2, and this creates the high surge at the nozzle. Also, a welding lead that has been in use for a while could be twisted or have a kink or the gas diffuser could become partially clogged with a buildup of spatter. These issues result in flow restrictions at the contact tip, which can only be overcome with more shielding gas pressure.
And the older they get, the more imperfect welding leads become. The need to clear out any imperfections or potential clogs that would restrict flow is why many welding flowmeters are designed to deliver 20, 30 or 50 psig of pressure to the solenoid valve to be released when the valve opens.
There are other types of shielding gas flowmeters offered in the industry that are calibrated at atmospheric pressure, or, zero psig. These are typically called “zero-comp” flowmeters as they release the flow of gas at atmospheric pressure with no back pressure whatsoever. So, when the solenoid opens, there is no wasteful back pressure to create the gas surge.
However, these lower pressurecompensated devices work better with newer welding leads rather than older leads. In applications, such as a construction site, fab shop or where equipment could be handled roughly and not well-maintained, these devices may not be ideal and can cause other issues.
In addition to reducing costs through waste-optimized shielding gas systems, another option to consider is blending gases onsite. Traditionally, MIG welding is done with pure argon or with a mixture of argon and CO2. Whatever combination a company uses, it typically orders the mixture to be delivered pre-blended in a cylinder. As welding has evolved, techniques used in different applications have become more specialized, with specific blends of argon and CO2.
Keeping in mind that many applications may require a different blend for every job, many welders seek the flexibility to change their mixture on the fly. For these welders, using a gas blender allows gas mixtures to be easily changed. This keeps companies from having to purchase various preblended cylinders, allowing them to minimize costs and streamline their gas purchasing.
But gas blenders can cost anywhere from $1,000 to $10,000, so a company should consider its gas use to determine a gas blender’s ROI. For a handful of stations, an investment of around $1,200 would likely suffice whereas, for 28 welding stations, a blender investment could be closer to $7,000. Cost benefit consideration shouldn’t focus only on the streamlined supply chain, but also in the reduction of downtime switching between jobs.
There is no hard and fast rule, but it’s always beneficial to examine company processes, workflows and supply chains to determine whether a gas blender may be a good fit.
It’s been estimated that more than 50 percent of the welding market uses packaged gas in the form of liquid dewars or high-pressured cylinders. For those companies, a system that provides continuous gas and is never shut down is worth exploring.
Bulk gas systems come equipped with an alarm that alerts the gas supplier to refill the system when it hits a certain, predetermined level. Conversely, when using packaged gases, changing cylinders is an in-house job that can be time consuming. During the time it takes to change the cylinder, welding productivity decreases. Over time, those costs add up.
An alternative is investing in a system with a continuous gas supply. These automatic changeover manifold systems have a gas supply on the left and right side with one as the primary supply and the other as the reserve. When the primary cylinder reaches a predetermined level of depletion, it seamlessly switches over to the reserve source leaving plenty of time to replace the empty cylinder(s). The former “reserve” side now becomes the new “primary” side and the system switches back and repeats the process when the new primary side goes empty.
In addition, fully automatic changeover manifolds are proving to be an ideal solution for high-pressure cylinders, liquid dewars and even bulk systems requiring a packaged gas backup. The manifold could be attached so that the bulk system is always the primary, but with a six- or 12-pack of high-pressure cylinders in reserve.
New technology is enhancing the capabilities of these automatic changeover manifold systems. With DataSmart from Harris Products Group, these systems are interconnected with data that can provide in-depth efficiency, usage analysis as well as alerts at pre-set levels so that replenishment becomes automatic.
Systems like DataSmart that plug into the Internet of Things can prevent waste by monitoring a cylinder or cylinder bank to determine the right time to change over to a reserve cylinder. For further optimization, users can easily program and adjust the changeover pressure settings to maximize gas usage and avoid sending cylinders back to the supplier with gas still left in them. DataSmart features a mass flowmeter to determine gas usage by measuring the molecules of gas consumed in the process.
Overall, understanding how to eliminate inefficiencies in a system can result in a significant cost reduction and ROI. By analyzing the data, it might be surprising to learn how much is wasted on shielding gas annually. If sufficient gas-saving protocols are not in place already, an investment based on unique needs could be a potentially massive windfall. There are many options out there, so companies should take advantage of the data to find a solution that maximizes efficiency and output.