Maintaining high-quality, contamination-free welds on materials like titanium and stainless steel is crucial in industries where weld integrity is paramount, such as aerospace, nuclear, pharmaceuticals, and biofuels. Standard gas shielding provided by conventional welding methods often falls short, especially under high heat input or when welding sensitive alloys. This is where Argweld Weld Trailing Shields® come into play, offering superior inert gas coverage to protect the weld area from oxidation and discolouration.
Argweld Weld Trailing Shields® are designed to extend the protection beyond the arc’s immediate vicinity, ensuring that it remains shielded from harmful atmospheric gases even as the weld cools. These shields are versatile, accommodating various welding processes, including GTAW (TIG) and PAW (plasma), and are adaptable to different workpiece geometries, from flat surfaces to curved pipes and cylindrical vessels.
Key features include a flexible silicone skirt for secure sealing, effective gas distribution systems to prevent turbulence, and customisable designs for specific welding applications. These shields are particularly beneficial in high-stakes environments where minimal contamination can compromise the weld's structural integrity and lead to costly failures.
The Argweld Weld Trailing Shield® technology, supported by complementary products like the Argweld® HotPurge™ System and PurgEye® Weld Purge Monitors, ensures that critical industries can achieve the highest standards in weld quality, minimising the risk of oxidation and enhancing the durability of welded components.
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The Need for Enhanced Inert Gas Coverage
In various industrial applications, mainly when dealing with sensitive materials like titanium and stainless steel, the standard gas shield provided by a typical Gas Tungsten Arc Welding (GTAW) or Plasma Arc Welding (PAW) torch may not always offer sufficient protection. The need for enhanced inert gas coverage becomes critical, especially in environments where even minimal contamination can compromise the quality of the weld. This is where the Argweld Weld Trailing Shield® technology offers a robust solution.
Certain alloys, such as titanium and specific stainless steels, are highly susceptible to contamination when exposed to oxygen, even at lower temperatures behind the arc shield. This susceptibility is particularly pronounced in industries like biofuels, aerospace, nuclear, and pharmaceuticals, where the purity and integrity of the weld are paramount. For example, the biofuels sector recommends an oxygen level of 50 ppm for shielding the molten weld pool, a standard that is difficult to achieve with conventional torch shielding alone.
Moreover, welding processes that involve higher heat input—such as those using high-current settings—can exacerbate the risk of oxidation and contamination. The standard arc gas coverage may prove inadequate under these conditions, leading to compromised weld quality.
The Solution: Argweld Weld Trailing Shields®
For those situations where the highest level of weld protection is required but using sealed welding enclosures is impractical or too costly, the Argweld Weld Trailing Shield® presents an efficient and effective alternative. This technology provides extensive inert gas coverage with minimal setup time, ensuring the weld remains free from oxidation and discolouration without needing a full enclosure.
The Argweld Weld Trailing Shields® are especially beneficial in industries where weld quality and protection against oxidation are crucial, such as in the aerospace, semiconductor, nuclear, petrochemical, food, biofuels, and pharmaceutical sectors. These shields ensure that even as the weld cools, it remains shielded from any potentially harmful exposure to atmospheric gases.
Inert Gas Selection and Flow Rates
Argon is the most used inert gas for shielding during welding, primarily due to its density and cost-effectiveness compared to helium. Argon is less likely to dissipate in turbulence, providing more reliable coverage. As a general guideline, a flow rate of 7 litres per minute is considered adequate for effective shielding when using Argweld Weld Trailing Shields®.
Design and Flexibility of Argweld Weld Trailing Shields®
The Argweld Weld Trailing Shields® are designed with flexibility in mind, accommodating a variety of torches and welding operations. Manufactured by Huntingdon Fusion Techniques (HFT®) under the Argweld® brand, these shields can be custom-made to fit specific torches and welding applications. For example:
HFT® can also modify these shields to provide additional protection if the welding conditions demand it, such as when there is high heat input or the need to shield hot metal on both sides of the fusion zone.
How Argweld Weld Trailing Shields® Work
Argweld Weld Trailing Shields® are specifically designed for use with GTAW (TIG) or PAW (plasma) welding torches. These shields offer a high level of additional inert gas shielding, supplementing the coverage provided by the primary torch. The shields come in various shapes and sizes, accommodating welding operations from flat surfaces to diameters as small as 25 mm.
Key features include:
Choosing the Right Trailing Shield
When selecting an Argweld Weld Trailing Shield®, several factors should be considered:
Conclusion
The Argweld Weld, Trailing Shield® technology, provides a versatile and effective solution for enhancing inert gas coverage during welding. Whether working with sensitive materials or under conditions of high heat input, these shields ensure that the weld remains protected from oxidation and discoloration, resulting in higher-quality welds and reduced risk of contamination. For industries where weld integrity is critical, using Argweld Weld Trailing Shields® is an invaluable tool in achieving the best possible outcomes in welding operations.
