Why orbital welding?

Orbital welding is a fully mechanical gas-shielded welding process in which electrodes including the arc are guided 360 degrees around round workpieces. The advantages are clear: high process reliability and reproducibility, short production times, a consistently high quality of the weld seam, as well as the ease of operation of the process and the comprehensive documentation.

 

In industries where thin-walled tubes are welded in consistently good quality, orbital welding comes into its own. These include semiconductor manufacturing, food technology, aerospace, pharmaceuticals and chemicals, as well as heat exchanger construction - in other words, wherever aggressive and corrosive media or high process pressures require leak-free piping and high hygiene standards.

 

Due to stricter requirements, an increase in quality awareness, and the shortage of skilled workers, the demand for orbital welding systems has been rising steadily for years. Increasing documentation requirements are also doing their part. Thanks to intelligent welding power sources and defined processes, this method meets international requirements.

 

An orbital welding system consists of a power source with control and cooling unit, the welding head with hose package for the supply of control signals, shielding gas, cooling medium and welding current. Welding heads are divided into closed and open types.

 

Orbital weld head types

Closed heads and the tungsten inert gas (TIG) welding process are used for thin-walled tubes - e.g. made of stainless steel or titanium - up to around 170 mm in diameter and wall thicknesses of 0.3 to approx. 3.5 mm.

The welding process takes place under constant conditions in the orbital welding head, which completely surrounds the pipe. Under a permanent shielding gas atmosphere, a TIG electrode is guided in a defined manner around the pipe via the welding head rotor. The pipes to be welded are butt-welded together (without gaps or offsets) by an arc. This requires good seam preparation: tubes cut at right angles, a consistently flat bevel, and a metallically clean and burr-free surface can be achieved by using state-of-the-art orbital tube cutting and beveling machines.

The dimensions of the welding heads have become more and more compact in the course of development, so that welding can now be carried out even in confined installation conditions. Closed welding heads are currently available for pipe diameters from 3 to 170 mm.

 

For larger wall thicknesses and pipe diameters up to 270 mm, open orbital welding guns are often used. In contrast to closed systems, the open arc allows filler material to be added to the weld pool in the form of cold wire. Multi-layer welds with thicker walls are also possible in this way.

 

Simple operation and fatigue-free work

Handling of the welding process using the closed welding heads as an example is simple: The head is opened and the two pipes to be welded are inserted without a gap. The pipe joint is aligned with the electrode. After closing the head and starting the process, the liquid-cooled head is reliably flooded with argon gas. After arc ignition, the electrode moves cleanly around the workpiece. Tarnish is avoided by the permanent shielding gas cover. Welding proceeds automatically, without misalignment or gaps, and with consistently high quality.

 

Intelligent power sources allow access to projects and parameters

Intelligent welding power sources guarantee maximum operating safety during the process: by entering workpiece-dependent parameters such as material, diameter and wall thickness, the power source automatically determines the currents, pulse times, welding speeds and, in the case of open welding guns, the amount of wire required for the application. The connected head type is automatically detected, so that the operator only has to call up the appropriate welding program and start the process before welding begins. Working with this system is so simple and reliable that even less qualified operators can achieve the best welding results in series production under constant general conditions.

 

With modern welding power sources, seamless data recording and backup in the customer's LAN is also a matter of course. The Orbimat 180 SW, for example, can be integrated into the customer's network via the integrated LAN interface: Interface communication with various customer systems is possible via the IoT/Industry 4.0-capable MQTT protocol. The entire welding process can thus be tracked immediately because operators, work planners and QA experts have access to projects and data at all times. All welding data and programs for each individual weld can be retrieved and documented without interruption, analyzed and adopted or optimized for future welds. Production processes can thus be better planned, and are also safer as well as more cost- and time-efficient.

All data can also be saved in the internal system memory or on an external USB data carrier. In addition to data such as pipe diameter, material quality and wall thickness, the customer can specify other parameters - for example, operator name, workpiece batch numbers, weld position number, pipeline isometric number, etc.