The heart of the flux-cored arc welding process is the tubular wire electrode that makes the FCAW process fundamentally different from MIG. Rather than just conducting an electric arc and providing filler to the molten weld pool, the tubular construction of the flux-cored wires allows it to be packed with slag formers similar in nature to those found on the outside of stick electrodes used for SMAW.
Whether the wire is designed for use with external shielding gas (an FCAW-G wire) or without (an FCAW-S wire), the core of these flux cored wires must serve double (and sometimes) triple-duty. They can alloy the weld pool and remove impurities to help improve the strength and toughness of the completed weld. Impurities are removed from the weld pool through slag formation, but the slag also helps support and shape the solidifying weld metal.
In short, the slag is what makes the process unique and provides flux cored arc welding with unique benefits for a wide range of applications.
Application One: Outdoor Structural Welding
Gas-shielded processes such as MIG are not generally recommended when the wind speed in the area of welding exceeds 5 miles per hour. However, when the weather is not cooperating with a pressing deadline, or maybe you are working in an offshore location, self-shielded flux-cored electrodes are the most economical means of completing critical welding jobs. Unlike gas-shielded wires, self-shielded wires can generate a sufficient volume of atmosphere-displacing gas to maintain weld quality even when the wind picks up.
But a porosity-free weld is only part of what makes the self-shielded flux cored electrodes a staple on construction sites nationwide. Wires intended for heavy-duty applications such as bridge and skyscraper erection need specially designed wires that provide excellent mechanical properties such as toughness to resist many natural and artificial forces. With one of these tough flux-cored wires and a well-designed welding procedure, it is possible to quickly and economically deposit weld metal on demand or fracture-critical structural components such as seismic-force restraint systems.
Application Two: Outdoor Home, Farm & Ranch Repairs
Of course, only some applications consist of splicing columns and making moment connections that exceed several inches in thickness. For those other applications, the modern “seismic” flux-cored wire is often too large in diameter for thinner materials and undoubtedly not as user-friendly.
To meet the needs of repairs around the home and farm, self-shielded flux cored wires exist that are smaller in diameter and easier to be successfully wielded by a broader range of skill levels. Like their large-diameter counterparts, these wires are still suitable for being brought to the outdoor workpiece. Still, the smaller diameter makes welding thinner materials, such as fencing, much easier with less risk of burn-through.
Application Three: Out-of-Position Welding
Flux-cored wires also can facilitate high-quality welding “out-of-position.” Not all welds can be easily made “in-position” with the weld joint resting on the workbench. In the production environment, it can be economical to invest in equipment that helps to allow easy movement of the workpiece to “position” parts. Still, for complex weldments, this may be a luxury.
Flux-cored wires have a unique advantage of a slag that solidifies to support molten metal when welding in the vertical and overhead positions. With high-quality welding wire and good technique, it is possible to produce very flat welds that can be difficult to distinguish from in-position welds.
It is possible to use MIG to weld out-of-position, but both deposition rate (productivity) and weld penetration will suffer compared to those all-position flux cored wires.
Unfortunately, not all flux-cored wires are suitable for welding out-of-position, but those that can are often classified and marketed as such. Wires intended for in-position welding only are often available in larger diameters and have a slower freezing slag that allows for high-amperage welding parameters to achieve the highest travel speeds.
Application Four: Rust, Scale, and Weldable Primer
Those who weld within the construction industry, know that bridges and skyscrapers start in the beam fabrication shop, where steel webs and flanges are joined into structural shapes such as angle, channel, and I-beams. Although every shop is different, many beam fabricators perform work in enclosed structures. However, raw materials are often stored in outdoor locations with at least some environmental exposure that leads to rust or necessitates the benefits of mill scale and weldable primer.
Although removing all potential contaminants from the base metal is “best practice,” it often becomes complicated to justify in the production environment as the part size increases. To maintain control of productivity and profitability, leveraging the welding process itself can be helpful. Remember that the slag of the flux-cored welding process helps to remove impurities from the weld metal to maintain good weld quality.
Application Five: The Heavy Duty
FCAW manufactures various components ranging from consumer goods to refinery components. Each of these applications demands different weld deposit chemical compositions to ensure the welds perform satisfactorily. Just as you can purchase wires for welding indoors or outdoors, or out-of-position versus in-position only, flux-cored wires are available in compositions ranging from carbon and low-alloy steel to nickel super-alloys and everything in between.
Conclusion
The flux-cored wire market is vast, meaning there are plenty of wires to choose from. However, if you are considering selecting flux-cored arc welding for your particular application, first consider the following:
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Will you be welding outdoors? If so, you may benefit from a self-shielded flux-cored wire. If not, a gas-shielded flux-cored wire may still help tackle dirty base material with less prep work.
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Will you be welding out-of-position? If so, you may benefit from an all-position flux-cored wire. Even still, large-diameter gas-shielded flux-cored wires can achieve deposition rates challenging to obtain with MIG.
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What kind of mechanical property requirements does your application demand? Chances are good that a flux-cored wire exists that will help you strike the best balance between optimal properties and productivity.
If you’re still unsure, reach out to the Red-D-Arc team! We have extensive experience with applications of flux cored arc welding ranging from field to shop. Contact us today to learn more and select the rental equipment you need to complete your job today!
Flux-cored arc welding (FCAW) is a wire-fed process like gas metal arc welding (GMAW/MIG). However, what makes FCAW a unique process is the filler metal. FCAW uses a tubular wire that generates slag during welding. While removing the slag after welding can be inconvenient, the slag is critical for the process to achieve good weld quality and provide unique benefits compared to MIG and other welding processes.
When it is time to select a flux-cored wire for your application, you may find that there is an extensive list of wires to choose from. Selecting the best wire—one that is easy-to-use and produces a high-quality weld deposit with suitable mechanical and chemical properties—requires a basic understanding of the basic wire types and capabilities.
Primary FCAW Wire Types: Self-Shielded and Gas-Shielded
In addition to producing a slag during welding that helps to remove base metal impurities, flux-cored wires generate gases that serve to displace the atmosphere around the molten weld metal. This displacement protects the weld metal from atmospheric gases such as oxygen and nitrogen that can lead to porosity or harm mechanical properties.
Self-Shielded Flux Cored Welding (FCAW-S)
Self-shielded flux-cored wires produce sufficient gaseous shielding, so no assistance (external shielding gas) is required. Self-shielded wires are suitable even in breezy conditions, such as outdoor construction and repairs. Remember that using these wires indoors can be challenging from an environmental health and safety perspective, even when strong ventilation is used.
Some self-shielded wires offer sufficient weld toughness—an ability to absorb energy before fracture—that makes them well-suited for structural fabrication in seismic areas and demand-critical welds on bridges and similar structures.
Of course, flux-cored wires also exist for “light-duty” applications around the house, garage, or farm and ranch. While these wires may not be as tough, they often provide more-than-adequate mechanical properties and are easier to use and available in diameters that complement commercial and light-industrial equipment. In addition to the local welding supply, it is often possible to find these wires at hardware and farm supply stores.
Gas-Shielded Flux Cored (FCAW-G)
Not all flux-cored wires are self-shielded, meaning that an external shielding gas (supplied in cylinders similar to those used when MIG welding) is required to achieve acceptable weld quality; these gas-shielded wires are not capable of providing sufficient atmospheric displacement on their own. The process using these wires is often abbreviated as FCAW-G (for gas-shielded).
The trade-off to needed external shielding gas is that the gas-shielded wires are often much more user friendly than the self-shielded wires while still providing improved tolerance to poor base metal conditions—rust, weldable primer, and mill scale—than MIG welding. FCAW-G is especially popular in the railcar, shipbuilding, and heavy equipment fabrication industries.
Common shielding gases for gas-shielded include 100% carbon dioxide and 75% argon/25% carbon dioxide. 100% carbon dioxide is a lower-cost option that typically offers improved base metal penetration, while the argon/carbon dioxide shielding gases usually provide a smoother arc and reduced weld spatter.
In-Position & All-Position Flux Cored Wires
In certain applications, it is possible to position the work (by hand, sometimes using equipment) so that the weld joint is roughly parallel with the ground. This is known as welding “in position.” Since the effect of gravity is not as detrimental, it is often possible to weld at higher amperages. This translates to improved deposition rates, welding travel speeds, and in many cases, improved welding productivity.
Some flux-cored wires are limited to welding in position only. The slag of these wires tends to freeze slower than those wires that are capable of welding in the flat, horizontal, vertical, and overhead positions, but a slow freezing slag often provides a very smooth weld bead contour and good penetration. Typically, these “flat and horizontal only” wires are available in larger diameters to allow the use of very high currents. A 3/32” wire, for example, is typically used between 350 and 500 amps!
If work cannot be positioned, resulting in weld joints in the vertical and overhead positions, an “all-position” flux cored wire must be used. Here, the slag is designed to freeze quickly to support the molten metal and prevent it from dripping or sagging when reasonable welding parameters are used.
Weld Deposit Composition: So Many FCAW Wires!
Some flux-cored wires are suitable for welding lower-strength carbon steels. In contrast, others are designed for welding higher-strength low alloy (HSLA) steels that derive strength and toughness from elements such as nickel, chromium, and molybdenum, among others. Specialty wire manufacturers even make flux-cored wires designed for welding stainless steels, exotic nickel-based alloys, and tool steel compositions.
Some available alloys are even designed for surfacing instead of joining so that exposed areas of base metals are more abrasion or impact resistant.
Conclusion
Flux-cored arc welding is an expansive process with many wire types: gas-shielded, self-shielded, all-position, in-position, carbon steel, HSLA steel, stainless steel, and more. If you ever feel overwhelmed by the sheer number of flux-cored wires in the welding marketplace, consider turning to AWS or CWB filler metal specifications. Often, these technical documents have electrode classification systems that help you compare products and descriptions of the intended uses of certain wire classifications.
If you’d prefer to save the reading for another time, don’t hesitate to contact Red-D-Arc. We are a knowledgeable team who can rent you the best equipment and advise on the optimal consumables—such as flux-cored wire—you will need for your flux-cored welding application.
The welding equipment used in pipeline welding is highly varied, as different types of pipelines require different welding techniques. Due to the specific challenges posed by this type of welding and its crucial role in global infrastructure and economy, pipeline welding is considered a distinct profession within the welding industry. Consequently, it necessitates the use of a wide range of specialized tools and equipment to facilitate the safe and efficient joining and repair of pipelines.
Pipeline Welding Challenges
Pipelines are like the veins of our planet, and each region has its own pipeline structures transporting natural gas, oil, water, and other vital infrastructure. Like veins in our bodies, pipelines are scattered everywhere. And very often, they are laid in uninhabited terrain with harsh environments, which makes a pipeline welder’s job a challenge on its own.
Any pipeline failure can lead to dramatic economic and environmental consequences. So, weld quality is crucial for pipeline integrity and environmental safety. Pipe welding is sometimes done manually but often employs automated welding equipment to improve weld quality.
Unlike horizontal plate welding, pipe welding requires making circumferential welds around the joint line. The welding process is far more challenging because you must keep the torch/electrode angle consistent as you travel along the joint. In addition, operators must reposition themselves as they travel around the pipe, which takes time and can put welders in uncomfortable welding positions out in the field. Welder fatigue, harsh environmental conditions, the challenge of maintaining the same arc travel angle, keeping an even joint gap, and many other challenges make pipe welding a complex job that requires specialized welding equipment.
Different Types Of Pipelines
The oil and gas industry primarily relies on pipelines for gathering, processing, and distribution. However, many different pipeline types are involved in these processes, and they all have unique challenges during their production.
There are five main types of pipelines:
- Gathering Pipelines
- Transmission Pipelines
- Distribution Pipelines
- Flowlines
- Feeder Pipelines
These pipelines vary in size, primary material, internal pressures, and the types of chemicals and aggressive agents the inside and outside of the pipes are exposed to. As a result, there are varying welding needs depending on the pipeline type you are working with. For example, joining a service distribution pipeline made of copper with a pressure of 6 psi has completely different welding equipment requirements than joining a carbon steel transmission pipeline of up to 42-in diameter with pressures up to 1,200 psi.
Pipeline Welding Equipment
Pipeline welding equipment is highly diverse and specialized for welding pipes of various materials and diameters. In addition, many advanced automated pipe welding solutions exist for different pipe materials and sizes. While manual pipe welding plays a significant role in the pipeline industry, automated equipment provides consistent arc manipulation patterns, speed, voltage, amperage, and work angles.
Besides the welding equipment, joining pipes also requires external and internal clamps, pipe stands, pipe lifting devices, pipe bending equipment, weld testing machines, and various auxiliary equipment. The need for these additional tools depends on the pipeline types and the location where the pipes are joined.
Welders also need to use personal protective equipment (PPE). Besides welding apparel, pipe welders use pancake-style welding helmets to prevent backlight exposure and ensure maximum eye protection from arc radiation, sparks, and spatter. In addition, pancake-style welding helmets are lighter than standard flip-up welding hoods, which reduces fatigue during days with extended hours under the hood.
Welding Power Sources
While a lot of the manual pipe welding is done with the well known E6010 and E7018 stick welding electrodes, the TIG, MIG, and Flux-cored welding processes are also often applied, depending on the pipeline type, material, pipe diameter, and other variables.
Joining pipelines in remote locations is not only challenging for your welding crew but for your equipment as well. Besides exceptional arc stability and built-in features, your welding power source must be made to perform in harsh environments.
For example, the diesel-powered Big Blue Air Pak from Miller is designed for heavy industrial applications and built to be one of the most reliable high-output welders in the world. This powerful unit can output 500A at 100% duty cycle or 600A at 60% duty cycle, allowing your welders to join the thickest of pipes efficiently and with little to no downtime. Its “Arc-Drive” automatically enhances stick welding, especially when welding pipe, by improving arc stability and preventing it from going out. Besides excellent stick welding capabilities, the Big Blue Air Pak includes MIG, FCAW, DC TIG, and submerged arc welding processes. As a result, you can join pipes in the most optimal way for your current job.
Another option is to use dual-output diesel-powered welders like the Dual Maverick 200/200X from Lincoln Electric. This workhorse of a welder can output up to 450A in a single mode or up to 225A in dual mode — it combines two welding machines into one, allowing your pipe welders to work simultaneously on the same pipe. Besides its support for MIG, DC TIG, and stick welding, it also supports arc gouging at up to 450A, allowing you to gouge bad welds quickly. In addition, its Downhill Pipe (CC) mode allows your operators to weld the pipes “downhill” with a more forceful digging arc during the root and hot passes and a softer arc when “stacking the iron” during the fill and cap passes.
Pipe Bevelers and Cutters
Cutting and beveling the pipe remains one of the most challenging aspects of pipe preparation. No matter how skilled your operators are, achieving a consistent bevel angle on the pipe is nearly impossible when manually severing with the torch. On the other hand, pipe fit-up and cut precision must be almost perfect for maximum joint quality and for the weld to pass the inspection.
Pipe bevelers and cutters allow you to accurately prepare the pipe joint quickly and consistently. Depending on the system, they are mounted inside or outside the pipe. An operator can easily position the beveler or a cutter in about five minutes or less and achieve clean cuts and bevel angles, making pipe welding far easier and with a lower chance of weld failure.
Pipe Heating Equipment
Preheating and post-welding heat treatment are often crucial to establishing a sound weld. Pipes made from various high-strength steel grades and alloys have specific preheating temperatures and often must undergo a process of stress relieving through post-welding heat treatment. In addition, the interpass temperature between each consecutive weld is usually provided in the welding specification sheet.
If the pipe joint is not appropriately preheated or the interpass temperature is incorrect, there are higher chances of weld cracking due to brittleness and hydrogen diffusion. Therefore, pipe heating equipment is vital for successful pipe joining.
There are various pipe heating technologies on the market, but most of them are based on induction heating, open flame heating, and ceramic resistance pads. High-quality systems not only provide sufficient pipe heating, but can also log the data and offer very accurate and uniform pipe heating. Unlike traditional open flame heating systems, induction heating systems like the Miller ProHeat 35 don’t cause water vapor condensation and won’t contribute to additional hydrogen buildup in the weld.
Rent Or Lease Pipe Welding Equipment From Red-D-Arc
Pipeline welding is a very diverse field and depending on the types of pipes you need to join, your equipment selection can vary significantly. For example, if you are a fabricator who joins pipes in the shop for your client, you may require completely different equipment than a contractor working on large transmission pipelines in the open and across the states.
Red-D-Arc has a massive fleet of pipeline welding equipment at your disposal. You can rent the necessary tools and avoid purchasing, storage, and maintenance costs. Investing in heavy-duty pipe welding equipment is costly and often doesn’t make financial sense. Many contractors move from job to job. So, it’s more cost-effective to rent and scale in and out with your equipment on an “as-needed basis.”
Contact us today, and our experienced team will help you determine the needed equipment based on the job at hand. Red-D-Arc has over 60,000 units of high-end equipment strategically placed across North America, and we can provide our tools to your job site, regardless of the location and equipment requirements.
Welding is a complex and varied practice, with everything from hobby-level art welding to industrial welding, shipbuilding, and even underwater welding available to skilled tradespeople.
The welding method uses high heat and electric currents, produces spatters of molten metal, and can even cause open flames. While proper welding procedures can minimize many of these risks, there’s always the potential for danger, so adequate safety equipment is essential.
A welding blanket is one piece of safety equipment that can be essential to keep on hand. What is a welding blanket, what is it used for, and what considerations should you give to your selection? Read on to learn more.
What Is a Welding Blanket?
A welding blanket is a large sheet of material the size, shape, and flexibility of a blanket you might put on your bed at home. Unlike a traditional blanket, however, a welding blanket is thick, heavy, and made of heat-resistant, flame-resistant materials, such as fiberglass.
When welding or performing related tasks like plasma cutting, grinding or sandblasting, your work can spray gobbets of hot metal away from a weld pool or cutting surface. These drops of hot metal can be anywhere from 2,000 to 5,000 degrees, capable of lighting other materials on fire, burning the operator, and causing all kinds of damage.
The operator will typically be protected by safety equipment such as heavy-duty gloves, a face shield, and a thick jacket that resists burns.
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Offshore welding equipment requirements in the oil and gas industry are different from those of a small welding shop or a large fabrication line. When working on an offshore oil rig, you want safety, integrity, durability, reliability, and versatility as prime pillars of your welding equipment.
Working with pressurized and flammable materials in an industry where every maintenance and repair interruption creates a profit bottleneck and poses a risk of devastating explosions, requires specialized equipment for all welding tasks.
Pipes and other critical infrastructure on the offshore rigs must be repaired quickly, efficiently, and most importantly, safely. And you cannot achieve this goal with subpar equipment. So, let’s discuss the offshore welding equipment requirements and see how you can benefit from proper equipment selection.
Offshore Welding Conditions
It’s not an overstatement to say that environmental conditions on offshore rigs are brutal. Extreme weather, rough seas, corrosive sea water, and powerful winds require equipment that can reliably perform in the most adverse situations. In addition, welders working on offshore platforms have to repair and install platform elements in noisy, damp, and cramped conditions with extreme weather, making all metalworking tasks more challenging than in most other industries.
Hurricanes and other extreme sea weather events are difficult, if not impossible, to predict. For example, Hurricane “Gustave” swept through the Gulf of Mexico in 2008, damaging more than 130 offshore platforms. Later that year, Hurricane “Ike” produced similar damage. Since it’s welders who repair the damage and keep rigs running smoothly, their personal protective equipment (PPE) and welding tools must be engineered to function even in challenging conditions.
Offshore Welding Equipment
The bulk of offshore welding equipment comes down to welding power sources, diesel generators, induction heating devices, fume extractors, PPE, welding consumables, filler materials, welding automation equipment, and shielding gas for arc welding processes. While you would generally see a similar list of welding equipment for most industries where welding is employed, offshore equipment must meet stringent requirements to perform reliably in harsh conditions.
Personal Protective Equipment
Welders on offshore rigs are at potential risk for electrical burns, eye damage from welding arc, health issues from toxic fumes and gases, exposure to dangerous levels of UV and IR radiation, physical injuries, frostbites, and develop hearing damage due to a noisy work environment.
Offshore welding typically requires working with high-amperage welding machines in less-than-ideal conditions using a shielded metal arc welding process (SMAW). High amperage, coupled with an arc welding process that produces a lot of sparks and welding fumes, requires adequate PPE to combat arc eye injury, like a heavy-duty welding helmet with an appropriate DIN shading level, and fire-resistant welding apparel that can withstand molten slag and metal droplets. In addition, welding respirators may be necessary, along with a welding fume extraction system.
Welding Power Sources
MIG, Flux-cored, TIG, stick, and submerged arc welding power sources for offshore welding can have up to 1500 amps of welding power, be single-process or multi-process units, and work standalone or as a part of multi-operator packs.
Welding on oil rigs means the power source might be exposed to corrosive salt water, harsh moisture-ridden winds, and possibly physical shocks, like bumps and tool hits. These machines must be built to withstand such an environment with rugged bodies made from heavy-gauge stainless steel.
Diesel generators or diesel-powered welders must have extreme-duty protective enclosures to minimize saltwater intrusion. In addition, they should be fuel efficient and produce a low noise level to reduce workers’ distraction and hearing damage. Diesel-powered welders should have excellent cold-starting abilities because offshore platform temperatures can get extremely low. Another significant advantage of diesel-powered welders is the provided auxiliary power for tools, and this benefit is exceptionally useful during post-hurricane repairs.
Stick welding equipment should be equipped with a voltage reduction device (VRD) to prevent electrical shocks to welders. VRD reduces open circuit voltage (OCV) to safe levels before the welding arc is initiated, which minimizes the chances of welder electrocution in cramped, wet, and damp areas.
Offshore rigs require welding everything from rails to heavy construction, pipes, and pressure vessels for barium sulfate and other compounds. The welds on offshore platforms have extremely stringent requirements, which means that the welding equipment must have impeccable arc quality and necessary features to maximize the weld integrity in every application.
Automated Welding Equipment
Automated welding solutions can significantly improve productivity, efficiency, and safety in the oil and gas industry. Weld automation bridges the skills gap and helps you deal with the skilled labor shortage while simultaneously improving your bottom line and weld quality.
Employing automation equipment like welding positioners, manipulators, turning rolls, fit up bed tank rollers, welding cobots, automated submerged arc systems, and other welding automation equipment can drastically cut the production time for pressure vessels, pipes, and other critical elements of offshore oil and gas platforms.
Some of the most critical automation solutions for offshore oil and gas extraction are automated pipe cladding systems. Offshore environments and subsea reservoirs are highly corrosive, and many of the extraction process failures are attributed to pipeline corrosion. The pipelines typically contain aggressive agents like organic acids, carbon dioxide, hydrogen sulfide, chlorides, sand, and other chemicals that cause steel pipe corrosion. However, the pipelines can last significantly longer when using automated cladding equipment to bond the corrosion-resistant alloys on the inside of the pipes used in an aggressive offshore environment.
Rent Or Lease From Red-D-Arc
The offshore oil and gas industry has an extensive range of welding needs. Unfortunately, it’s almost impossible to accurately predict the scope of welding equipment an offshore rig will need in any given year, especially when you account for hurricanes and other destructive natural events.
Thankfully, welding is so versatile that you can join almost all elements on the oil and gas platforms as long as you have the right equipment. But, it doesn’t always make sense to buy fleets of advanced welding power sources and automation equipment. Instead, many welding businesses rely on rental equipment because it’s difficult to predict the hurricane season and the yearly oil and gas industry requirements.
By renting or leasing your welding equipment, you can scale in and out of the welding job and still keep your contract for the maintenance and repair of rigs and platforms. Red-D-Arc offers welder rentals and welding equipment fleet management services for many industries, and provides extreme-duty performance and reliability, even in the harshest environments.
Red-D-Arc experts have an in-depth understanding of materials, products, and specific job-type needs, and we stand ready to help you prepare for your next offshore season. Contact us today, and our team will work with you closely to develop and implement the solutions you need.
