FIELD OF THE INVENTION
The Invention relates to manufacturing of water wall panels used in High
Pressure Boiler. The invention particularly relates to chamfering operation at the
end of the tubes. More particularly, the invention relates to chamfering operation
for the terminal ends having different angles for the field welding with the
furnace upper front outlet header at site.
BACKGROUND OF THE INVENTION
In Boilers, water wall panels are one of the important components. The water
wall panel comprises of straight panel as well as terminal bend end panels (Fig-
1) which will be welded with the furnace upper front outlet header at site.
In the conventional method of manufacturing, individual bend tubes are edge
prepared on both the ends. One end of the bend tubes are welded to the water
wall panel and other end is left for field welding with the furnace upper front
outlet header. But in this method many a time deviation occurs because of actual
height required is less than the required height.
Due to the difficulty in the above method, water wall panels are manufactured
with required bend so that one welding operation is avoided. The terminal end of
the bend is alone to be chamfered for site welding. For this method the portable
chamfering machine is lifted with crane and chamfering operation is carried out.
Again in this method, it is not possible to prepare the chamfering operation for
the terminal ends having different angles which is required to be connected with
furnace upper front outlet header at site.
The following are the drawbacks in the above processes :-

Cycle time is more, Requirement of more man power and machining speed is
slow.
The positions are also difficult with more tools setting time.
Due to the above facts, the finishing of the chamfering surface is also not
satisfactory.
Hence it was necessary to develop a method and device for chamfering
operation of the terminal end of the tubes having different angles.
OBJECTS OF THE INVENTION
An object of the present invention is to develop a device and method for
chamfering of taper terminal ends of water wall panels used in high pressure
boilers that can perform chamfering of terminal ends at different angles in a
mass production in an easy manner and in quick time.
SUMMARY OF THE INVENTION
Accordingly the conventional chamfering machine is fitted with the developed
fixture. The two ends of the proposed device is fixed with the top and bottom
portion of the chamfering machine through nuts and bolts. To do chamfering of
terminal bend end of water wall panels, there is a need to tilt the chamfering
machine to the desired angle either 45o, 60o or 90o. For that as mentioned
above the conventional method is not suitable due to more man power, Quality
of chamfering is also not satisfactory and unsafe. The developed device having 3
slings are welded with the curved strips.
The purpose of the 3 slings is to give required angle to chamfering machine. To
chamfer the terminal bend end of the water wall panels, C –clamp is clamped to
the hole of the respective slings .The hook of the crane chain is inserted in the

respective C –clamp and chain to be lifted suitably up to the height of the bend
end chamfering portion.
After setting the desired angle, the fit up devices required for chamfering is fitted
with the chamfering machine. Then the chamfering machine is clamped with the
tube and chamfering is under process. After finishing of the chamfering to the
required length, the similar process can be carried out for the other tubes also.
Due to the new method, the engagement of man power is less. Also the quality
of the chamfering is good.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig 1 – Shows the water wall panels with inclined tubes for edge preparation at
the end of tubes for field welding with furnace upper front outlet header.
Fig 2 – Shows the conventional edge preparation machine with developed
device for chamfering at different angles.
Fig 3 –Shows the developed device for chamfering at different angles of the
tubes in the water wall panels.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
PRESENT INVENTION
The set up (12) shown in figure 2 comprises of existing chamfering machine (10)
with the developed fixture (11) shown in fig 3.
The Fixture (11) comprises of three plates which will give the required angle 45o,
60o or 90o to the chamfering. The fixture as shown in (fig 3), will be attached
with the chamfering machine shown in (10) (fig 2).The top portion (1) of the
fixture (11) will be fixed with the top portion of the conventional chamfering
machine (10). Referring to Figure 3, The bottom portion of the fixture (11)
comprising strips (5,6) will be fixed with the bottom portion of the conventional
chamfering machine (10).

The fixture (11) comprises bottom strips (5 and 6) welded with the curved strip
(8 and 9).The curved strip (8 and 9) is of radius 450mm approximate and width
of 850mm. First the sling (4) is welded in horizontal position and the other two
slings are positioned and welded by calculating the arc length obtained by
multiplying the radius of the curve strip and angle in radians (for 60 degree and
45 degree respectively). The Sling (4) will be welded with curved strip (8 and 9).
The purpose of sling (4) is to tilt the chamfering machine to 90o. Sling (3) is
welded with the curved strip (8 and 9). The purpose of sling (3) is to tilt the
chamfering machine to 60o. Sling (2) is welded with the curved Strip (8 and 9).
The purpose of sling (2) is to tilt the chamfering machine to 45o . The slings (2,
3, and 4) are provided with holes, each hole having radius of 25mm. The
purpose of holes is to hold the device by the C- clamp (not shown) which in turn
is tied with the hook of chain of crane. The metal strip (1) having 3 holes of
radius 12mm. The strip (1) will be attached with the top portion of the
chamfering machine (10) .The portion (5, 6, and 7) will be attached with the
bottom portion of the chamfering machine (10).
To do chamfering 90o bend portion of the panel, the chain (not shown) is to be
fitted with the C-clamp (not shown) which is put in the hole of the sling (4) and
lifted suitably.
To do chamfering 60o bend portion of the panel, the chain (not shown) is to be
fitted with the C-clamp (not shown) which is put in the hole of the sling (3) and
lifted suitably.
To do chamfering 45o bend portion of the panel, the chain (not shown) is to be
fitted with the C-clamp (not shown) which is put in the hole of the sling (2) and
lifted suitably.

WE CLAIM :
1. A chamfering device for taper terminal ends of water wall panel
comprising :
- a pair of strips (8,9) curved with a radius of 450 mm and width of 850
mm;
- the said strips (8,9) welded with bottom strips (5,6) at one end;
- a strip (1) welded at the second end of the curved strips (8,9);
- the said strip (1) provided with holes for clamping with top portion of a
chamfering machine (10);
- the free end of bottom strips (5,6) are welded with plurality of cross
plates placed transversely for strengthening purpose;
- the outer ends of bottom stripes (5,6) provided with holes for clamping
with the bottom portion of the chamfering machine (10); wherein
- the curved strips (8,9) disposed with 3 slings (2,3,4) at particular positions
for giving the required angle of 450, 600 and 900 when the machine (10) is
suspended along with the device from the sling in the crane after being
tied in the holes provided in the slings (2,3,4).

2. The device as claimed in claim 1 wherein the slings (2,3,4) are provided
with holes for fixing with c-clamp.
3. A method of chamfering of the terminal end of bend tubes of water wall
panels having of 450, 600 and 900 inclination by lifting the chamfering
machine with the c-clamp placed in the holes of sling (2) and then
performing the chamfering operation for 450;

unloading the machine from the sling (2) and lifting the machine with the
c-clamp placed in the holes of sling (3) for performing chamfering
operation for 600 inclination ; unloading the machine from sling (3) and
the lifting the machine with the c-clamp placed in the hole of sling (4) for
performing chamfering operation for 900 inclination.