Welding Shielding Gas: Improves Weld Quality and Reduces Rework

How to save money on shielding gas without sacrificing weld quality

Shielding gases are often one of the most expensive items purchased by businesses to support their welding operations. However, industries cannot avoid this price because shielding gases protect the weld region from ambient pollution, which might damage the weld joint.

That is why, while searching for solutions to reduce the cost of shielding gases, it is vital not to sacrifice the quality of the welding process. A minor investment in adequate gas equipment might result in considerable cost savings while maintaining welding quality.

No. 1: Understand How Much Gas Is Wasted

The first step is to study each welding process and establish standards. Determine the exact quantity of gas required to create an appropriate weld. This is critical for determining where gas is lost in your operations—you may be shocked at how much gas you lose due to an incorrectly configured flow rate.

Companies that establish gas use standards will almost certainly realize that they squander too much shielding gas in their operations. Once you’ve verified that waste exists in the process, the following step is to identify and eliminate it.

No. 2: Lower the Gas Surge

When you pull the trigger on the welding torch, surges occur. Most shielding gas flow control equipment, whether from a cylinder or a pipeline, is intended to function at pressures ranging from 20 to 30 pounds per square inch gauge (PSIG), with pure CO2 applications operating at pressures as high as 50 PSIG. When you hit the torch trigger, an upstream pressure of 20, 30, or even 50 PSIG escapes the welding nozzle, squandering a lot of gas.

Some of the devices that considerably limit the amount of shielding gas surge during trigger pulls include gas guard regulators, point-of-use orifices, low-pressure flowmeters, and surge-reducing hoses (see Figure 1). These flow-control devices restrict or prevent high flow rates from turbulating the gas and drawing oxides and nitrides into the weld.

Introducing a pressure-regulating device into the gas system is the most effective technique to minimize shielding gas surge. Use of inline-restricted orifices as a technique to preserve shielding gas should be avoided. These devices will not eliminate gas surge if they are not positioned at the appropriate location in the gas stream.

Point-of-use orifice fittings may be effective and are often a low-cost option. However, for the orifice fittings to function effectively, they must be positioned exactly in front of the solenoid valve. The surge issue will persist if it is put somewhere else in the gas stream, such as at the regulator or flowmeter. A gas-reducing regulator, on the other hand, may be put anywhere in the gas stream and perform successfully by taking the high upstream pressure and lowering it to remove the surge. When the solenoid valve opens, there will be less than 50 PSIG of upstream pressure; instead, there will be around 10 PSIG of line pressure.

Zero-compensated shielding gas flowmeters, which are calibrated at atmospheric pressure (zero PSIG), allow shielding gas to flow with no back pressure. There is no unnecessary back pressure to cause the surge when the solenoid opens (see Figure 2).

Low-pressure-compensated devices are ideal for newer welding leads or for a fresh installation. Older equipment may have kinks or other obstructions in the line, necessitating the use of extra shielding gas pressure to clean them out.

These devices, however, may not be suitable for use on construction sites, fab shops, or wherever equipment is handled harshly and inadequately maintained.

No. 3: On-Site Gas Blending

When MIG welding, welders traditionally utilize pure argon or a combination of argon and CO2 provided pre-blended in a cylinder. Welding procedures have gotten more sophisticated as time has passed, with certain argon and CO2 mixtures necessary to obtain the appropriate outcomes. Given that numerous applications may need a different blend for different duties, you may desire the ability to adjust the combination to better suit different applications. Gas mixes may be readily adjusted using a gas blender. As a consequence, businesses may avoid buying many pre-blended cylinders, lowering expenses and streamlining the gas purchase process.

Gas blenders may range in price from $1,000 to $10,000, therefore calculating the ROI is critical. If you just have a few welding stations, a $1,500 investment would most likely enough for your mixing requirements. The outlay for 28 welding stations, for example, may be closer to $7,000.

In a trade school or other institution where every welding booth utilizes the same gas mix, a costly gas blender may not be a worthwhile investment. In such instances, it may be advantageous to continue utilizing packaged gas in pre-mixed cylinders. Examine your operations, workflow, and supply chain to see whether a gas blender is a good fit for you.

No. 4: Install a Continuous Gas Supply to Reduce Downtime and Increase Productivity 

It is believed that packaged gas accounts for more than half of the welding market. These businesses may benefit from investing in a continuous gas system that never shuts down.

Every minute of downtime costs a lot of money. If you employ packaged gases, replacing cylinders becomes an in-house process, and profitability suffers during the cylinder replacement. How long does a cylinder swap take? What is the expense of that? It may quickly pile up.

When a main cylinder reaches a specified degree of depletion, an automated changeover manifold system easily shifts over to the reserve supply, giving plenty of time to replace the empty cylinder without halting the operation.

Fully automated changeover manifold systems are becoming more popular as a bundled gas backup option for high-pressure cylinders, liquid dewars, and bulk systems. A manifold may be connected to ensure that the bulk system is always primary, but with a reserve supply of six or twelve high-pressure cylinders.

Such technologies may assist high-production businesses in avoiding downtime. New technology is boosting the capabilities of these automated changeover systems in a variety of ways, including in-depth efficiency and consumption data analysis and email or text notifications when gas levels are low (see Figure 3). A mass flowmeter, which measures the number of gas molecules consumed throughout the process, is included in certain data systems.

Connected systems save waste by monitoring cylinders or cylinder banks to see whether they need to be turned over to a reserve cylinder and by making it simple for users to preset and alter changeover pressure settings. This has the ability to enhance gas utilization while avoiding shipping cylinders back to suppliers with usable gas remaining.

No. 5: Consult with your gas equipment manufacturer or supplier.

Your gas distributor and gas equipment manufacturer are both excellent resources for maximizing shielding gas utilization. Rely on their knowledge to establish the best course of action for spending less on shielding gas.

By eliminating inefficiencies in your welding process and shielding gas system, you may save money and improve your ROI. You may be astonished to find how much you spend on shielding gas each year after examining the data. If you do not have enough gas-saving practices in place, an investment tailored to your specific requirements might be a major windfall for you. There are several possibilities available, so use the data to help you discover a solution that optimizes your efficiency and production.

Source link