Essay On Orbital Welding

1 Introduction

Among the various metal joining processes, orbital TIG welding has become a well established method, although a considerable deficient of information about the various possibilities of this challenging technique still under research. Aerospace industry, pharmaceutical industry, high speed rails, nuclear industry, food industry, microelectronic industry , oil and gas industry rely on orbital welding.

In this report basic information is provided about the orbital weld process and the related equipment: technical approach, advantages, common and special applications, but also restrictions and limits.

Orbital welding utilizes the gas-tungsten- arc-welding (GTAW) process as the source of the electric arc that melts the base material to forms the weld. During GTAW an electric arc forms between the work piece and a tungsten electrode. To initiate the arc, a high-voltage signal will ionize the shielding gas to generate a passage for the weld current. A capacitor dumps current into the arc to diminish arc voltage to a point where the power supply can adjust. The power supplies responds to the demand and supply current to maintain the arc.

2 What is Orbital Welding?

Orbital welding is the first choice for the joining of tubes whenever high quality results are required. The welding moves around the tubes to be joined, guided by a mechanical system. The name orbital comes from the circular movement of the welding tool around the work piece.

Generally, orbital welding technique covers two main fields of application:

a) Tube to tube / pipe to pipe joining

b) Tube to tube sheet welding

3 Welding Procedure

Using manual welding, it is very tricky to achieve the utmost standards of quality and safety. This is mainly due to ce...

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... Defects

The orbital welding has defects that include misalignment, lack-of-penetration, a huge crevice and discoloration due to poor internal diameter purge. This weld would be considered unacceptable by any standard.

8 Disadvantages

Followings are the disadvantages for the orbital welding process:

• Increased equipment cost

• More equipment issues

• Additional welder training

• Additional maintenance and spares

9 Conclusion

Along with the current methods of using TIG cold and hot wire welding, there has also been steady progress in the development of other welding which allows a whole range of new applications. Orbital welding can provide reproducible quality using wide-ranging techniques. This can be achieved to a high standard even when using unusual materials, small tube diameters, thick walls, and even within a difficult working environment.

10 References