Welding in an industrial context is, like other forms of welding, a simple process in principle. It essentially involves the combination of high temperatures, pressure, and sometimes filler material to make two separate components continuous with one another. This allows contractors to secure piping assemblies, repair heat exchangers, and perform several other installation and repair projects.
While welding is simple in principle, there are several challenges involved. Due to these welding challenges—contamination being one notable example—multiple welding methods have evolved, each with their own purpose, optimal conditions, and ideal welding surface. To learn more about these types of welding services for industrial fabrication, read our guide to five different types of welding services and the welding process as a whole.
Shielded Metal Arc Welding
Shielded Metal Arc Welding (SMAW), or stick welding as many refer to it, is a fairly common and traditional industrial welding option. The “stick” in this case is an electrode that conducts electricity into the base material, melting the metal to join two components together. The electrode has a flux coating around it, and both the electrode and the flux coating gradually melt as it heats up during use. This flux coating provides the shielding hinted at in the name—as it melts it becomes a shielding gas that staves off surrounding contaminants. This steadily melting electrode and flux provide a constant supply of shielding so your project is never at risk of contamination.
Stick welding is especially useful for rusted metals or areas you haven’t cleaned beforehand. Also, while this is a flexible technique useful for many industrial applications and materials, it is also ideal for thick, substantial metals and it is not tailored to welding thinner metals.
Gas Metal Arc Welding
Meanwhile, Gas Metal Arc Welding (GMAW) is an alternative, one with basic similarities to stick welding with some marked differences. Like stick welding, Gas Metal Arc Welding (also called MIG welding for metal inert gas) utilizes an electrode that gradually melts onto the base material during use.
Unlike stick welding, the GMAW electrode does not have a shielding flux coating. To compensate for this lack of shielding, welders pump an external shielding gas in, often inert helium or argon gases. Very similar to GMAW/MIG welding, Metal Active Gas (MAG) welding pumps in external gases, yet these are a mix of oxygen, carbon dioxide, and argon.
This welding method is best for welding thinner metal components consisting of sheet metal or tubing. Also, GMAW is best for inside welding and requires you to clean the base surface thoroughly before operating.
Gas Tungsten Arc Welding
Another type of welding service for industrial fabrication, one that’s complex and hard to master, is Gas Tungsten Arc Welding, or TIG which stands for tungsten inert gas. Like GMAW, tungsten welding requires an external shielding gas and a thorough preemptive cleaning to prevent contamination.
Unlike most welding methods, TIG welding does not require the integration of filler material at all times. For combining larger metal components, welders operate their welding torch and manually feed a filler rod that matches the base surface material with their other hand. If they’re working with thinner, more sensitive metals, they can forgo the filler. Also, unlike other methods, the TIG welding electrode does not melt away during welding due to tungsten’s extremely high melting point.
Overall, TIG welding requires skill and practice to master, yet yields polished and precise welds when mastered. Introducing filler manually affords an expert much more control, as does the shorter tungsten electrode, making it a perfect welding method for external surfaces that need to look pristine.
Flux Cored Arc Welding
Flux Cored Arc Welding (FCAW) is yet another welding technique. FCAW represents an evolution of the MIG and SMAW methods. Instead of using a flux-coated filler as SMAW does, Flux Cored Arc Welding utilizes filler with a tube of flux material at its core, hence its name.
There are two variations of FCAW: self-shielded Flux Cored Arc Welding (FCAW-S) and gas-shielded Flux Cored Arc Welding (FCAW-G). FCAW-S needs no shielding beyond the protection afforded by the flux core as it melts and forms a barrier. Meanwhile, FCAW-G incorporates both the flux and external gas shielding.
While this process is generally more costly, it represents a much faster welding option than MIG and SMAW. Also, it’s more regular and reliable and does not lose effectiveness when environmental conditions change. Consider choosing FCAW particularly if you have a thick metal that necessitates significant penetration for adequate coalescence.
Submerged Arc Welding
Unlike many welding strategies, Submerged Arc Welding (SAW) is, for one, is a mechanized rather than a manual process. Engineers set the parameters for a weld and let it run automatically, requiring extreme precision before running.
Also, the reason Submerged Arc Welding is considered “submerged” is that before the wire electrode encounters any weld spot, the system coats the surface with a granular blanket of flux. In this process, you don’t actively see the electrode fusing the metal components because this granular flux covers the entire surface. The purpose of this flux is its thorough shielding from contaminants. Because the blanket of flux restricts outside substances, professionals need not input shielding gas like they would with other welding techniques.
The benefits to SAW include fast, even deposition, and little capacity for human error if programmed correctly. Though its mechanization is overall a plus, it does limit the potential weld positions available. Due to its mechanized nature, SAW is an able solution for regulated, circular welds around a pipe or other cylindrical component, as well as for straight line welds.
The Benefits of Hiring a Welding Contractor
Rather than spending time and money in trying to weld components yourself, hire a welding contractor instead. Welding professionals have significant experience with industrial welds and access to the tools to utilize many welding types, choosing the right method based on what would best fit your needs.
If you partner with SVI Dynamics, we offer comprehensive specialty on-site welding services in addition to pipe design and installation, custom machining, valve repair, and several other services. As our team deals with your facility over time, they learn how to best respond when something goes wrong, while an outside contractor lacks such helpful inside knowledge. This makes choosing a contractor like us easy. We also offer help with your gas turbine exhaust system or any other gas path solutions, if that’s also an area of need for you.