FIELD OF INVENTION
The present invention relates to a novel method of manufacturing of the Seal
bank of high pressure and high temperature steam generator, or particularly to
a methodology of production of the seal bands at the same time with uniform
profile for the full length.
BACKGROUND OF FTHE INVENTION
Normally high pressure and high temperature steam generators are having back
pass panels with size 3.28 m x 21.18 m. The loose tubes are getting welded with
these panels at the site.
Some gap is maintained between extended wall floor and the back pass panels.
This gap helps in preventing any damage to the critical superheater tubes due
to differential expansion. So, there are chances that the flue gas may go out of
these gaps. To prevent any leakage of flue gas the seal bands has been provided
along with Refractory box. At site refractory boxes has been welded on these seal
bands and refractory material has been filled inside. The seal bands are having
profile matching with outside diameter of the tube (as shown in Fig. 5).
So, seal bands have been made by plates of thickness approx. 5 to 6 mm First it
was manufactured by choosing the plate of required size. Then it has been cut
for the calculated length of straight portion and hole size. Then holes have been
made. Then this holed plate had been bent in die and punch at the marked line.
The shape of the seal bands by this method has been shown in Fig. 4.
Due to this pressing the circular hole has been enlarged and taken the shape of
elliptical holes. Because of this it was not matching with the tube profile. Due to
which amount of weldment to be deposited has been increased. So, the heat
input and the number of shifts required to do the welding also increased. This
process took almost three to four shifts to weld one seal band on one panel.

But the present invention elimination all these problem of conventional method
by providing a novel method as claimed hereinafter.
SUMMARY OF THE INVENTION:
A method for manufacturing seal bands required for back pass panels of high
pressure and high temperature steam generator comprises the steps of: i)
calculating of the width for making two seal bands; ii) fixing of the length as per
the pitch requirement and marking of the late for bending at a specific distance
from the edge of both sides; iii) matching with template for shape verification and
after that marking as per the pitch requirement, drilling is processed; iv) after
drilling, the plate is subjected to gas cutting through marking the center line of
all holes characterized in that, two seal band has been obtained simultaneously
at the same time which has uniform profile for the entire length
OBJECTS OF THE INVENTION
It is therefore the principle object of the present invention, to provide a method
of manufacturing seal band which is required for the back pass panels of high
pressure and high temperature steam generator.
Another object of the present invention to provide a method of manufacturing
seal band, which produces two seal bands simultaneously at the same time and
has uniform profile for the entire length.
Yet another object of the present invention to provide a method of manufacturing
seal band, which has accurate hole drilling, which matches exactly with tube
outer profile.
Further object of the present invention to provide a method of manufacturing
seal band to save the material by making two holes at a time and helps in
improving productivity due to less weldment deposition.
Another object of the present invention to provide a method of manufacturing
seal band, which reduces the cycle time of the welding of seal bands with panel
tube and eventually helping in saving of material.

Yet another object of the present invention to provide a method of manufacturing
seal band, which saves welding time substantially.
Further object of the present invention to provide a method of manufacturing
seal band, which is safe, rapid and environment friendly.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
It is to be noted, however, that the appended drawings illustrate only typical
embodiments of the present subject matter and are therefore not to be
considered for limiting of its scope, for the invention may admit to other equally
effective embodiments. The detailed description is described with reference to
the accompanying figures. Some embodiments of system or methods in
accordance with embodiments of the present subject matter are now described,
by way of example, and with reference to the accompanying figures, in which:
Figure 1 illustrates assembly of seal band (Item No.-2) with Refractory Box at
site.
Figure 2 illustrates prior method seal band (Item No.-2) picture.
Figure 3 illustrates proposed method of making seal band.
Figure 4 illustrates Detailed drilling.
Figure 5 illustrates Seal band (Item No.-2) after gas cutting at the center.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
The present subject matter relates to a method of manufacturing a seal band
which is to be used for the back pass panels of high pressure and high
temperature steam generator.
The refractory boxes are generally welded on this seal band for checking any
leakage of the flue gas from the furnace to the outside.
According to one of the embodiment of the present invention, Fig. 1 shows the
ultimate two distinct seal bands.

However, the sealing material is shown is Fig. 2, where first the width of the plate
has been calculated for making two seal bands. The straight portion of the seal
bands (as shown in Fig. 2) is X mm and the hole radius is Y mm, then the width
of the plate will be (2X+2Y) mm. The length has decided as per the pitch
requirement. After that the plate has been marked for bending at distance X from
the edge both sides. The bending has been done in Press brake for the required
corner radius from both sides. After that it has been matched with template for
shape verification. Then this plate became in the shape as shown in Fig. 2.
After giving the appropriate shape to the plate, marking is processed as per the
pitch requirement and then it is subjected to drilling (as illustrated in Fig. 3).
The gas cutting has been done as per the marking of the center line of all holes
and two seal band is obtained as a result of it (as shown in Fig. 1).
Those seal bands have uniform profile for the entire length. The each band is
shown in Fig. 4.
The non-limiting advantages of the present invention :
i) The method facilitates in reduction of the total time required of welding of the
seal band to the panel to one shift.
ii) The cycle time is also reduced to more than half because of the method as
claimed hereinafter.
iii) The method also eliminated the difficulties in welding process.

WE CLAIM:
1. A method for manufacturing seal bands required for back pass panels of high
pressure and high temperature steam generator comprises the steps of :
i) calculating of the width for making two seal bands;
ii) fixing of the length as per the pitch requirement and marking of the late
for bending at a specific distance from the edge of both sides;
iii) matching with template for shape verification and after that marking
as per the pitch requirement, drilling is processed;
iv) after drilling, the plate is subjected to gas cutting through marking the
center line of all holes characterized in that, two seal band has been obtained
simultaneously at the same time which has uniform profile for the entire length.
2. The method for manufacturing seal bands required for steam generator,
wherein the bending has performed with press brake for the required corner
radius from both sides.
3. The method for manufacturing seal bands required for steam generator,
wherein the straight portion of the seal bands (Item No.-2) is X mm and the hole
radius is Y mm, then the width of the plate will be (2X+2Y) mm.