A Closer Look at Shielding Gas Management in Heavy Industrial Wire Welding

In industrial welding, every aspect of the process is scrutinized for optimization. One crucial component often overlooked is the control of shielding gas flow, a factor that can significantly impact both cost and weld quality. In this article, we delve into the realm of shielding gas management, exploring how new digital gas control (DGC) technology is revolutionizing wire welding applications, particularly in terms of efficiency, cost savings, and quality control.

The Crucial Role of Shielding Gas in Heavy Fabrication

Shielding gas is the unsung hero of the welding process, providing a protective barrier that prevents atmospheric contamination of the molten weld pool. However, the traditional methods of regulating shielding gas flow have been fraught with challenges, including gas surges, inconsistent flow rates, and wasted resources. These issues not only inflate operational costs but also compromise weld quality, leading to defects such as porosity and inconsistency along the weld seam.

While shielding gas adds just a few cents to each meter of weld, who wouldn’t want to reduce shielding gas costs by up to 20%, or about $1,000 annually per machine? Who wouldn’t want to eliminate the downtime and hassle of swapping cylinders? Most importantly, who wouldn’t want to eliminate a root cause of porosity and the cost associated with weld defects?

New digital gas control (DGC) technology found today’s most modern wire feeders, such as ESAB’s RobustFeed Edge, delivers the peace of mind that comes from using each liter of gas in accordance with weld procedure specifications. DGC provides a level of precision, confidence and savings not previously possible with single-stage external pressure regulation devices and standard wire feed units.

The Evolution of Digital Gas Control (DGC) Technology

The integration of new digital gas control technology in select wire feeders presents an opportunity to achieve substantial cost savings, reduce downtime associated with cylinder swaps, and eliminate weld defects. By ensuring precise gas flow according to weld procedure specifications, digital control offers unprecedented levels of precision, confidence, and efficiency compared to traditional single-stage external pressure regulation devices and standard wire feed units. Through the utilization of a proportional flow valve and advanced sensors, including a differential pressure sensor and an absolute pressure sensor, these feeders can accurately regulate gas flow rates, minimizing waste and optimizing welding performance.

As shown in the figure above, digital gas control reaches the set flow rate faster and ensure an accurate flow rate. Conversely, standard technology systems greatly overshoot, then take more than five seconds to reach the set value. Additional benefits of digital controls include the ability to:

• Regulate flow to the correct rate independent of cylinder pressure or gas flow restrictions, which preserve weld integrity as cylinders run low.
• Eliminate the need to calibrate the system upon first use.
• Eliminate the need to recalibrate the system when switching torches or changing gas mixes, increasing uptime.
• Eliminate shielding gas surge when trigger is initially pulled.

Harnessing Digital Gas Control Technology for Enhanced Performance

Gone are the days of relying on standard On/Off solenoid valves with limited control options. Instead, modern feeders equipped with Digital Gas Control (DGC) technology boast a sophisticated proportional flow valve. This valve offers variable control, allowing for precise adjustment of gas flow rates to meet specific welding requirements.

But that's not all – the DGC system goes even further by integrating two essential sensors: a differential pressure sensor and an absolute pressure sensor. The differential pressure sensor regulates the gas flow rate in liters per minute, while the absolute pressure sensor determines the mass flow rate. Together, these sensors work in tandem to precisely and swiftly regulate gas flow, ensuring optimal performance with every weld.

ESAB's TruFlow Digital Gas Control technology takes this precision to the next level, guaranteeing that the gas flow reaches the desired rate swiftly and accurately. This not only enhances operational efficiency but also contributes to consistent weld quality.

In addition to precise control, DGC offers a range of other benefits. One significant advantage is its ability to regulate flow independently of cylinder pressure or gas flow restrictions. This feature safeguards weld integrity, even as cylinders approach depletion. Furthermore, DGC eliminates the need for initial system calibration, saving valuable setup time. Moreover, it eliminates the hassle of recalibration when switching torches or adjusting gas mixes, thereby maximizing uptime and productivity.

Cost Savings and Operational Efficiency with DGC

Furthermore, DGC technology presents inherent cost-saving advantages beyond gas conservation. By optimizing gas usage and reducing wastage, DGC diminishes the need for frequent cylinder changes, thereby minimizing disruptions caused by swap-outs and lowering inventory management overhead. This not only streamlines workflow but also enhances operational efficiency by ensuring uninterrupted welding processes. 

Inherent Gas Cost Savings

DGC technology inherently provides savings. Users need to do nothing special or extra to save money. In addition to eliminating gas waste, DGC can eliminate 20 cylinder changes per station, per year.

Gas Flow Rate	Daily Gas Use	Cylinder Life	Annual Changes (225 work days)
15 1/m	2,700 l/day	3.7 days	61
20 l/m	3,600 l/day	2.78 days	81

* 90 minutes arc-on time per shift, two shifts per day
** 10,000 usable liters per cylinder

Reducing the number of cylinders used reduces downtime associated with cylinder swap-outs, the possibility of a weld defect when gas runs out in the middle of a seam, spare cylinders in stock and rental charges and delivery frequency.

No Surge

Conversely, digital gas control virtually eliminates waste. For instance, DGC can eliminate up to 20 cylinder changes per station annually, resulting in significant time and cost savings. Additionally, by virtually eliminating gas surges that commonly occur during arc starts, DGC prevents wastage and potential weld defects, such as porosity. This innovative technology not only enhances productivity but also simplifies gas flow control, offering users the flexibility to adjust settings effortlessly and ensuring consistent weld quality across operations.

	Hose Length	Set Gas Flow	Arc Starts Per Day	Work Days Per Year	Gas Cost Per Liter ($)	Daily Surge Gas Waste	Gas Waste Per Year ($)
Traditional Single-Stage Regulators	10 m	31.78 CFH	1,000	225	0.002	1,835 l	991
Feeder w/ Digital Gas Control	10 m	31.78 CFH	1,000	225	0.002	0 l	0

Quality Control

ESAB’s DGC also adds protection not available with other systems:

1. The system has an adjustable gas pre-flow time with a default value of 0.1 seconds of gas pre-flow, which is standard for carbon steel. If the gas flow rate does not reach 90% of the set value after 0.05 seconds, the arc will not start and the system displays an insufficient input pressure error message.
2. If the system detects more than 2 l/min of flow deviation from the set value for a few seconds, it initiates a controlled termination of the weld using the programmed weld sequence (e.g., post-flow and crater fill) and will display a warning.
3. If the system detects sudden and total loss of pressure (e.g., the gas hose becomes disconnected), it terminates the weld immediately to avoid further issues.
4. Risk of leakage due to over-pressure. Most solenoid valves cannot withstand excessive pressure, which can cause leakages. If a DGC system senses a pressure exceeding > 7 bar, it will not allow the arc to start and will display an over-pressure error code.

Conclusion

In summary, the integration of digital gas control technology marks a significant breakthrough in the management of shielding gas for wire welding applications. By effectively addressing common challenges like gas surges, inconsistent flow rates, and quality control issues, DGC not only boosts operational efficiency but also generates substantial cost savings and enhances weld quality. As industries strive for heightened productivity and precision in their welding processes, DGC emerges as a pivotal technology, delivering tangible benefits without imposing additional burdens on operators. Embracing DGC isn't merely a step towards optimization; it's a monumental leap towards excellence in industrial welding. Moreover, with the TrueFlow DGC technology present in cutting-edge wire feeders such as ESAB’s RobustFeed Edge, users can access the most precise gas control system available. DGC facilitates uniform flow rates across welding operations, thereby bolstering consistency and quality while simultaneously reducing gas expenses, all with minimal additional effort required from operators.

Enjoying our series on Heavy Industrial Welding? Follow the links below to read more.

1. A Guide to Heavy Industrial Welding
2. Key Considerations for Heavy Industrial Operators
3. Heavy Equipment Maintenance: Prolonging Lifespan and Maximizing Efficiency
4. Pulsed MIG Technology: Boosting Heavy Industrial Welding Efficiency
5. The Role of Wire Feeders in Heavy Industrial Applications
6. Innovations in Heavy Industrial Welding: Shaping the Future of Fabrication
7. Transforming Heavy Industrial Welding Operations with Digital Solutions
8. Specialized Filler Metals for Exotic Alloys in Welding
9. A Closer Look at Shielding Gas Management in Heavy Industrial Wire Welding
10. Exploring the Benefits of Low Manganese Filler Metals in Heavy Industrial Welding