OrbitaL welding
Orbital welding is a specialized type of welding in which the arc is mechanically rotated through a 360 degree rotation (two to 180 degrees) around a static part, such as a pipe, in a continuous process. This process to fix operator error in welding processes(GTAW) has been considered. In orbital welding(Orbital Welding)The welding process is controlled by the computer and reduces the intervention of the operator in welding. This process is especially for high quality welds (especially in loopsWFI andPW and gases that are used in the pharmaceutical industry) are used.
History
Orbital welding process by research supervisor, Pavlecka. HV and engineer Meredith Russ of the company Aircraft Northrop, more than 50 years ago, to fix an operator error in GTAW was invented.
Equipment
The main components of an orbital welding system include the orbital welding power supply, controller, welding head and tungsten grinder mechanism. For welding special sizes and different materials, the cooling system (cooling water) will be used. Many factors affect the quality of welding, including the length of the arc, the size and frequency of the welding current pulse, the welding speed, the shielding gas, the quality of the material from which the tube is made, the type of filler, welding preparation and thermal conductivity.. Finally, to have a high-quality weld, it is necessary to know exactly how to set all the parameters mentioned for orbital welding.. Application Welding process
Achieving the highest standards of quality and safety in manual welding is very difficult, and this is due to the special position of welding, overhead andWelding hand-down For example, limited user access to the welding position often results in defective welds. In order to have complete control over the molten pool(Weld Pool), a complete interaction between gravity and surface tension force should be established in different positions of the torch.
Using technical mechanized methods, certain parts of the welding process are used with mechanical parts. Remember that the welder will always monitor and control the welding process. Ideally, before welding, all welding parameters It is fully programmed by the controller, but in practice, with all the variables, it is often necessary for the welder to take corrective action..
For orbital tube welding of closed heads(enclosed weld heads) is used, which is a fusion process according to the standard ASME SectIX is a successful automatic orbital weldingGTA is a weld that variables and periodic samples or tests for weld penetration are monitored by the operator.. Note that the changed variable is a basic skill and can be easily lost. Training and experience are required for an operator to succeed in acceptable welding.
Successful automatic orbital GTA welding depends on several important variable parameters, which include programming of the welding machine and adjustment of the welding head. Repair and maintenance of the machine The welding head of the orbital welding machine is often an influential factor in the welding quality. The internal parts of the welding head are damaged due to improper use and so-called half-burntcharring is charcoal (carbon) that causes electricity to conduct and short circuit the flow of current through tungsten.
The welding head machine has a precise mobile gear system that can get dirty over time and need cleaning. A successful orbital welding is also dependent on the use of high quality tube material. Usually single tube (nine tubes) and 316 L stainless steel fittings for automatic orbital welding.GTA is used. Successful orbital welding also depends on the purity of the type of argon gas, which is used as a support gas and a shielding gas. (backing and shielding gas) is used. Minimum gas purity for normal industrial use995.99% and for food and pharmaceutical use, it should be ultra pure gas with percentage98.99™ should be used, and clean equipment (including valves, regulators, and flow control) should be used for gas purging.. 
Usually, rubber parts should not be used for gas filling because rubber absorbs and releases moisture and oxygen. Moisture and oxygen (in argon) are among the harmful pollutants and cause disturbances in the quality of orbital welding. Welding test(Weld Coupon), it is used on pieces of metal or steel tube to evaluate the welder's skill, usually this test is done at the beginning of the work shift and when a variable parameter is adjusted or changed and at the end of the shift. (If the welding inspector sees fit, this frequency can be increased.)
Each welding test must be checked and performed internally and externally for complete penetration, suitable weld width and other criteria. For small diameters, a welding test is usually required. That's it.
The welding test must have full penetration and proper width. Changes in the integrity of the weld represent a problem that must be solved to continue welding. Orbital welding is usually performed only on the tube, due to several reasons and the most important of all is the outer diameter of the tubes. It is a product that is very important to close on the welding head machine.
Today, automatic orbital weldingGTA is used as a standard connection method in the semiconductor and pharmaceutical industries for gas and liquid systems. These systems are rated based on the percentage of purity and sensitivity in gas leakage. In all industries that produce valves, connections, Regulators, gauges and other parts for high purity applications( egWFI andPW) since the mid-1980s, orbital welding has been developed. For tube welding for high purity applications only from closed head machine(fully enclosed weld head) is used.
Materials
Orbital welding almost always with technique(Tungsten Inert Gas) TIG/GTAWIt is done using permanent electrodes and, if necessary, TIG methodWith cooling system ( Could Wire Feed) is used. The easiest way to control the heat input generated by TIG weldingFor orbital welding of tubes, orbital welding heads are used, which include a clamp device, a TIG electrode.and a protective gas cylinder. Many different metals can be welded, including: high-temperature, corrosion-resistant steels, inorganic and low-alloy carbon steel, nickel alloys, titanium, copper, aluminum, and related alloys. 
Tube diameter
according to the precision of TIG orbital welding, even the smallest standard tube diameter, i.e. 6.1 mm size, can be welded. On a large scale, tubes with diameters above 170 mm with a thickness of 5.3 mm can be welded with closed chamber weld heads .) can be welded. These welding heads allow the torch to be positioned very precisely and the tube to be held with high security. The ineffective shielding gas in a closed space prevents the generated heat even with the most sensitive materials. For tube diameters between 8 and 275 mm, open welding heads can be used.) which are control files. used. (except for high purity purposes). 
A flexible hose system to connect the welding head is connected to the power source of the orbital welding machine, which connects the argon gas, cooling water and wire filler to the welding machine. The wire filler depends on the type of welding work during welding. Thick tubes require the use of additional materials, while thin tubes can be welded without additional wire. To create a high-quality weld, it is essential that the edges of the tubes are free of any impurities and pleats. Cutting tubes with small thickness to medium dimensions, a saw - right angledIt will be suitable. For high thickness tubes, it is necessary to carefully prepare the cutting edge of the tube, for example using U-groove cross-section. Commercial and market sectors
Due to the ability of orbital welding to achieve high purity results, this type of welding has found a very suitable place in the construction of clean room equipment in the semiconductor industry. Orbital welding is currently used in piping and manufacturing equipment for the food industry, pharmaceuticals, Chemical engineering, automotive engineering, biotechnology, shipbuilding and aerospace have been expanded. Automatic orbital welding is also used in the construction of power plants (thermal power plants). The materials used in this industry must be resistant to the pressure of high mechanical loads and high temperature created by the materials passing through the tubes. There should not be any seams or holes in the joints and welds, because these weak points can lead to subsequent cracks. This problem, in turn, can have serious consequences in the failure of parts. For this reason, tubes are often made with alloy. Nickel is made with a thickness of 200 mm.feed wire – hot orbital moves around the tube. This new type of orbital welding machine has created a lot of interest in this field, with the increasing prosperity of the power plant construction industry, a rapid and unprecedented search has begun to create methods for producing steel tubes resistant to high temperatures. 
Conclusion
In addition to conventional TIG welding methodsCold and wire welding, great progress in FCAW / MAG / MIG weldingIt has been created that has many new applications in various industries such as aerospace, pharmaceuticals, automobiles, etc.
Orbital welding can provide reliable welding with recoverable quality using a wide range of techniques and methods.Even this quality can be achieved with an excellent standard and unusual materials, thick tubes, low diameter tubes and even very difficult work environments.The cost of orbital welding equipment is 5 to 10 times the cost of conventional welding equipment, but its efficiency is several times that of conventional TIG welding .is. (2 to 3 times).
Raymon Group with a team of professional engineers with the latest equipment in the world is ready to work on your orbital welding projects with a brilliant history of activity in this field.Stay with the best with our selection. Please fill out the form below for product purchase advice.
