In orbital welding, the tool rotates 360° (or 180° in double-up welding) around a static workpiece. It was created to reduce operator error in Tungsten Inert Gas (TIG) welding (also known as Gas Tungsten Arc Welding (GTAW)) and ensure a uniform weld around pipes and tubes, which is challenging with manual welding.
The computer-controlled orbital welding technology produces high-quality, consistent welds without operator intervention. Two important uses are tube-to-tube/pipe-to-pipe and tube-to-tube sheet connecting.
Roderick Rohrberg of North American Aviation devised the method in 1960 to fix fuel and hydraulic fluid leaks on the X-15 rocket research plane. It was possible to move orbital welding machines between building sites in the 1980s, thanks to advancements in control systems, mobility, and power supplies.
In this reading, we’ll explore what orbital welding is, its application, diagram, types, and how it works. We’ll also learn its benefits and drawbacks.
Let’s get started!
What Is Orbital Welding?
In orbital welding, the welding arc revolves around the workpiece (in an “orbit”) while a specialized machine clamps the tube or pipe to be welded. A computer manages the welding parameters, allowing for their storage and subsequent reuse, which greatly enhances the process’s repeatability.
One type of orbital weld uses a wire feeder to give metal for the arc, while the other uses the orbital welding system’s encased electrodes and tungsten inert gas. Every approach has advantages.
Since the 1980s, a high-purity orbital welding industry has produced fittings, gauges, regulators, valves, and more. High-purity tube welding requires an enclosed weld head. Engineers must operate the equipment in this highly automated process.
Welders may need to correct variables after entering welding parameters into the equipment. Material quality affects orbital weld quality. Industrial applications use 316L stainless steel tubing and 99.9995% pure argon for shielding and backing gas.
Application Of Orbital Welding
Orbital welding is a crucial technology in industries where precise welds are essential, such as in the manufacturing of stainless-steel tubing for pharmaceutical processes, aerospace components, and high-purity systems.
This technology ensures clean, sterile welds, ensuring the integrity of critical components in aerospace systems. It is also used in semiconductor manufacturing, pharmaceutical and biotechnology, food and beverage processing, power generation, the petrochemical industry, refineries, and other sectors.
Orbital welding ensures hygienic welds, adhering to strict sanitary standards and maintaining product quality. It is also used in other industries such as automotive, medical, oil and gas, and construction.
Diagram Of Orbital Welding
Related: What is Spot Welding? Its Application & How it Works
Types Of Orbital Welding
The common types of orbital welding are as follows:
Gas Metal Arc Welding
Wire feed welding is a method where an inert gas like helium, carbon dioxide, or argon is used to keep the weld from getting contaminated. The consumable electrode is fed wire constantly as it travels.
Metal Inert Gas (MIG) welding is the fastest and most frequent wire feed pipe welding method. However, unstable sidewall fusion and penetration make GMAW risky for high-specification applications and typically require reworking.
Gas-tungsten arc welding
An inert shielding gas and tungsten electrode form a small arc at the workpiece during GTAW welding, preventing oxidation and other contaminants. Welds are precise and constant due to the welding process control. Proper gas control improves weld purity, which results in stronger welds.
The approach works in many environments. Operators can set up GTAW outside with wind screening and planning, but this is rare. GTAW is more complicated and harder to learn than other welding methods. GTAW takes lots of practice.
Beam-arc laser welding
This fusion welding method joins metal parts by using laser beams. It is common in automated high-volume applications like the automotive sector. Due to its energy density, laser beam arc welding can melt the joint edges without harming a vast region.
Its high aspect ratio welds with minimum heat input are one of its main advantages over other arc welding technologies. The equipment size and cost of laser beam arc welding limit its use to purpose-built settings.
Plasma-arc welding
PAW welding uses plasma and shielding gas, making it a more advanced GTAW welding method. Plasma arc welding generates heat with a tungsten electrode, like TIG welding. Plasma arc welding generates high-quality welds independent of material thickness due to arc control.
PAW’s higher heat-affected area than TIG welding might generate heat distortion or metal strains that damage or destroy the workpiece. Using large weld heads limits PAW’s surroundings.
Flux-core arc welding
FCAW welding is forgiving and gives welders more alternatives because it uses flux-core wire. The flux core protects the weld from impurities and environmental influences. FCAW works in isolated areas without shelter.
It is difficult to use for welding thin-walled materials because the flux core requires higher amperage to initiate the arc than GMAW or GTAW. Even in thick-walled stainless steels, excess heat can cause heat distortion. Welding heat distortion can make meeting standards harder.
Submerged Arc Welding
SAW, an older welding method, uses a continuously fed wire as an electrode and flux that falls out of the hopper to bury the weld. It produces high-quality welds quickly, but it requires welding in a fixed, flat position. SAW’s main drawbacks are process immobility and material waste.
Equipment For Performing Orbital Welding
The power supply (which includes an integrated computer control), the welding head, and, if necessary, a wire feed system are the three primary components of an orbital welding system. Specific parts or materials might also need a water/coolant system.
Programmable Power Supply
This device lets you adjust several parameters, such as the welding head travel speed, shielding gas flow, wire feed options, current intensity, and pulse rate. The power supply ought to be small, lightweight, and able to control at least four axes on a single person.
Welding Heads
While different applications may call for different-sized heads, your weld head should always hold the electrode in place, control the welding current flow, keep the temperature at the ideal level, and apply pressure to the workpieces being welded.
Wire Feeder
If necessary, the wire feeder can be integrated into a separate system or welded into the device’s head.
Water/Air Coolant System
In addition to insulating the welding operator from the heat input of the operation, the coolant system uses either air or water to keep the welding equipment from overheating.
How Does Orbital Welding Work?
Orbital welding is a highly repeatable process that uses a specialized machine to clamp a tube or pipe while the welding arc rotates around the workpiece. The welding parameters are set by a microprocessor, making the process highly repeatable.
Before starting an arc, several steps must be taken to ensure the piece is ready for the weld. These include cutting the tube or pipe ends, facing or beveling the pipe, cleaning the tube or pipe, using a ceriated tungsten electrode, aligning the two ends inside the weld head, purging oxygen from the inside of the tube or pipe, and programming the welding parameters.
To use orbital welding, the weld head, material being welded, O.D. size, and wall thickness are entered into the power supply, which generates a pre-developed program. This program includes four or more welding levels, control welding speed, and adjusting amperage to achieve uniform, fully penetrated welds. To fully understand programming needs, schedule orbital welding training.
After completing these steps, the tungsten rotates 360 degrees around the workpiece to create a uniform weld. It is recommended to test an initial weld and make adjustments to the welding parameters as needed for your application.
Benefits Of Orbital Welding
Compared to manual welding, orbital welding offers several benefits that contribute to the overall quality of the weld.
Usability
A trained operator must comprehend, be familiar with, and know how to set up orbital welding machines. With the right operator, an orbital system makes it considerably easier to get a consistent and reliable weld.
Great Weld Quality Results
The consistency of the output from the automated orbital welding equipment, which closely monitors and extremely precisely regulates all the process parameters, has a substantial impact on quality in addition to eliminating the need to stop and restart.
If the joint preparation and base material qualities are consistent, the orbital solution will accurately execute the pre-programmed welding technique, yielding consistent results.
Consistent Weld Bead Results
There is no need to pause and resume the weld during regular operation because the weld head goes around the pipe smoothly and automatically. Consistent penetration and fusion improve the quality.
Increased Productivity
A manual weld necessitates a change in “setup” on every quadrant for every pass, but a weld head only needs to be set up once per weld joint. The weld schedule that is input into the machine takes into account variations in the feed rate of the fill material, weld current, arc voltage, and travel speed.
The electrode angle may necessitate only minimal adjustments from one pass to the next. This expedites the welding process and eliminates weariness and discomfort, which can cause uneven welds.
Drawbacks Of Orbital Welding
While orbital welding offers several benefits, some drawbacks still exist. But are they enough to override the advantages it offers? Let’s find out!
Training
Many technical and vocational colleges offer training in manual welding techniques and industry standards. Training on particular equipment is typically only provided by vendors in specific locations because there are not many intensive orbital welding training programs.
Costs of Equipment and Maintenance
Power supplies and weld heads for orbital welding are rare. They cost more than standard hand welding setups since they are manufactured in small quantities and frequently for specific applications.
Additionally, unlike manual welding equipment, specific orbital welding equipment is not readily available at nearby building and hardware stores. In some cases, it can be harder to repair or fix things quickly if a weld head or controller gets broken.
High-Quality and Consistent Joint Preparation
Consistent weld joint preparation is necessary for the majority of piping welding applications. Equipment and consumables for joint preparation must, therefore, be taken into account and factored into the solution’s cost.
Time Spent Setting Up
Orbital welding requires setup time because it is very precise. In certain situations, this preparation time could be longer than what manual welding calls for.
FAQs
What is the orbital welding method?
A specialized machine clamps the tube or pipe to be welded as the welding arc revolves around the workpiece (in a “orbit”) in orbital welding. The welding process is very repeatable since a computer controls the parameters, which may be saved and used again.
When to use Orbital Welding?
Orbital welding should be used when manual welding would be difficult or dangerous and also when large quantities of welds are required because it is fully automated and highly repeatable.
What is the difference between orbital and TIG welding?
Speed/Productivity.
An orbital welding system can weld a pipe connection in one pass. However, a manual TIG welder separates the pipe circle into portions, requiring setup and prep time for each section.
Is orbital welding difficult?
In short, the answer is no. Experienced welders can learn the procedure and discover new job options in areas they may not have previously thought about with the right training.