Orbital welding is Automatic Tunguston inert gas welding. It eliminates chances of manual errors in welding. It creates identical welds for hundred of times hence accuracy in welding. - Steel Fabricators Leeds
Orbital welding was first used in the 1960`s when the aerospace industry recognized the requirement for a superior joining technique for aerospace hydraulic lines. A mechanism was created in which the arc from a tungsten electrode was rotated across the tubing weld joint. The arc welding current was regulated having a control system thus automating the whole process. The result was a more precision and reliable method than the manual welding method it replaced.
Orbital welding became easy for many industries during the early 1980`s when combination power / control systems were developed that operated from 110 V AC and were physically sufficiently little to be carried from place to place on a construction site for multiple in-place welds. Present day orbital welding systems offer computer control where welding parameters for numerous applications can be kept in memory and called up when needed for a specific application. The skills of a certified welder are thus built into the welding system, producing enormous amounts of identical welds and leaving significantly less room for error or defects.
Orbital Welding Equipment
In the orbital welding process, tubes / pipes are clamped in place and an orbital weld head rotates an electrode and electric arc around the weld joint to make the required weld. An orbital welding system consists of a power supply and an orbital weld head.
Power source: The power supply / control system supplies and controls the welding parameters based on the specific weld program created or recalled from memory. The ability supply provides the control parameters, the arc welding current, the ability to drive the motor in the weld head and switches the shield gas (es) on / off as necessary.
Weld Head: Orbital weld heads are usually of the enclosed type and provide an inert atmosphere chamber that surrounds the weld joint. Standard enclosed orbital weld heads are practical in welding tube sizes from 1/16 inch (1.6mm) in order to six inches (152mm) with wall thickness` of up to 0.154 inches (3.9mm) Larger diameters and wall thickness` could be accommodated with open style weld heads.
The Physics of the GTAW Process
The orbital welding process uses the Gas Tungsten Arc Welding process (GTAW) since the source of the electric arc that melts the base material and forms the weld. In the GTAW process (also referred to as the Tungsten Inert Gas process - TIG) a power arc is established between a Tungsten electrode and also the part to be welded. To start the arc, an RF or high voltage signal (usually 3.6 or 7 KV) is used to break down (ionize) the insulating properties from the shield gas and make it electrically conductive in order to pass through a tiny quantity of current. A capacitor dumps current into this electrical path, which decreases the arc voltage to a level the location where the power supply can then supply current for the arc. The power supply responds to the demand and supplies weld current to keep the arc established. The metal being welded is melted by the intense heat with the arc and fuses together.
Causes of Using Orbital Welding Equipment
Many reasons exist for for using orbital welding equipment. A chance to make high quality, consistent welds repeatedly at a speed close to the maximum weld speed offer benefits to the user:
o Productivity. An orbital welding system will drastically outperform manual welders, often paying for the cost of the orbital equipment in one job.
o Quality. The caliber of a weld created by an orbital welding system with the correct weld program will probably be superior to that of manual welding. In applications for example semiconductor or pharmaceutical tube welding, orbital welding may be the only means to reach the weld quality requirements.
o Consistency. Once a weld program has been established an orbital welding system can repeatedly perform the same weld hundreds of times, eliminating the normal variability, inconsistencies, errors and defects of manual welding.
o Orbital welding works extremely well in applications the place where a tube or pipe being welded cannot be rotated or where rotation of the part is not practical.
o Orbital welding may be used in applications where access space restrictions limit the physical size the welding device. Weld heads works extremely well in rows of boiler tubing where it might be difficult for a manual welder to use a welding torch or observe the weld joint.
o Many some other exist for the use of orbital equipment over manual welding. Examples are applications where inspection of the internal weld is not easy for each weld created. By looking into making a sample weld coupon that passes certification, the logic holds when the sample weld is appropriate, that successive welds produced by an automatic machine with similar input parameters also need to be sound.- Steel Fabricators Leeds