FIELD OF INVENTION
The present invention relates to an Orbital Welding system with cam
arrangement and Laser Vision based seam tracking device for welding of nozzle
to drum of different materials.
BACKGROUND OF THE INVENTION
Joining of drum to nozzle components can be done directly by fusion welding. An
apparatus of orbital system with cam arrangement and Laser vision sensor
based seam tracking device for GMAW or SAW process are known in boiler
industry. The GMAW or SAW welding process constitutes an automated/semi
automated process achieving a high productivity due to its less cycle time as
compared to other SMAW welding processes. Thus, the GMAW and SAW welding
processes are quite suitable for production of jobs like drum to nozzle, header to
nozzles, valves, and other similar jobs.
Currently drum-nozzle welding joint of carbon steel to carbon steel material is
done by SMAW process but the process time is quite long and the productivity is
less. Further, the weld exhibits defects like slag inclusion, cracks, under-cut. In
the macro structure of the weld-joint, the heat affected zone is found to be
higher. The effectiveness of a welding process is largely dependent on a factor
namely, cycle time reduction, which constitutes a difference of the length of a
work piece before and after the welding process. In order to achieve the
effectiveness including maintaining economy of the process, it is important to
produce defect free welds which might require a lower rework. It is therefore
necessary to first determine the effects of the functional parameters on the
technical parameters of the weld including an optimum condition to maintain a
good quality of weld.

United States Patent 7560662, B2dt, Amador et al. discloses a system and
process for external structural welding of piping materials, and similarly-shaped
pressure boundary components, for use in pipe fittings, and a nozzle welding for
weld overlay in structural applications.
This prior art method describes an orbital welding equipment adapted to apply
an external structural weld overlay on a nozzle section of a pressure vessel
having a hemispherical head.
United States patent 4288020 dated 8 Sep 1981, Sealers et. al. describes a
tracking type welding apparatus where a torch is allowed to follow a probe along
a weld seam and the probe senses the lateral seam deviations and stores the
data in a pin cam. The data relating to the deviations are later used to move the
torch in the same manner. The pin cam is operated remote from the torch and
the probe assembly and is electrically synchronized.
OBJECTS OF THE INVENTION
It is therefore, an object of the present invention to propose an orbital welding
system with cam arrangement and Laser vision sensor based seam tracking
device adaptable to nozzle to drum welding processes.
Another object of the present invention is to propose an orbital welding system
with cam arrangement and Laser vision sensor based seam tracking device
adaptable to welding process for butt joint of different materials which reduces
the cycle time.

A Still another object of the present invention is to propose an orbital welding
system with cam arrangement and Laser vision sensor based seam tracking
device adaptable for different welding processes to join different materials.
A further object of the present invention is to propose an orbital welding system
with cam arrangement and Laser vision sensor based seam tracking device
adaptable to welding process for buttering or weld overlay, which provides a
weld chemistry according to the code of highest quality welds.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Figure 1 - a schematic representation of an orbital welding system with
cam arrangement and Laser vision sensor based seam tracking
device for nozzle to drum welding according to the invention.
SUMMARY OF THE INVENTION
According to the invention an orbital system with cam arrangement and Laser
vision based sensor seam tracking system for GMAW and SAW welding is
proposed. The inventive apparatus of orbital system with cam arrangement and
Laser vision sensor based seam tracking system technology reduces the
operational time.
In the orbital system with cam arrangement and laser vision sensor based seam
tracking device, the welded joint according to the invention, exhibits substantially
small heat affected zone and without any defect.

The procedure of drum to nozzle welding is a complex configuration which can
be carried-out by the inventive system in a narrow groove area by avoiding
interferences and accessibility problem.
The system is enabled to generate the required mechanical properties in the
welding assembly, including welding of the similar/dissimilar material
combination by adapting the SAW or GMAW welding process, and thus produces
a fusion welding of nozzle to drum shell in a narrow groove. The system is
capable to track the complex configuration in the drum nozzle weld. The system
can be easily mounted on the nozzle.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
OF THE INVENTION.
Figure 1 shows an Orbital welding system with cam arrangement and Laser
Vision sensor based tracking device for welding of nozzle to drum of complex
configuration. The system comprises a mounting assembly (4) having a cross
slide and a weld head assembly. The weld head assembly comprises a flexible
means in the form of a laser vision sensor based long narrow groove nozzle (5,6)
with controls. The weld head assembly further comprises a plurality of orbital
weld head (3) for welding of a nozzle (2) to a drum (1). This system can be
mounted easily in the nozzle (2) and operated in a smaller area of narrow groove
by avoiding interferences and operational inaccessibility.
WE CLAIM
1. An orbital welding system with cam arrangement and laser Vision Sensor
based Seam tracking device for complex welding of nozzle to drum, the
system comprising a mounting assembly having a cross slide and a weld
head assembly, the weld head assembly having a flexible means in the
form of a laser vision sensor based long narrow groove nozzle with
controls, and a plurality of orbital weld head for welding of a nozzle to a
drum.
2. The system as claimed in claim 1, wherein the Laser sensor is fixed
outside the narrow groove, and is enabled to guide the torch to carry out
the welding.
3. An orbital welding system with a cam arrangement and a laser Vision
Sensor based Seam tracking device for complex welding of nozzle to
drum, as substantially described and illustrated herein with reference to
the accompanying drawing.

The invention relates to an orbital welding system with cam arrangement and
laser Vision Sensor based Seam tracking device for complex welding of nozzle
to drum. The system comprises a mounting assembly having a cross slide and
a weld head assembly, the weld head assembly having a flexible means in
the form of a laser vision sensor based long narrow groove nozzle with
controls, and a plurality of orbital weld head for welding of a nozzle to a
drum.