FIELD OF INVENTION
The present invention relates to a method of profile machining in high thickness
pipe materials to fabricate tees, shorter arm elbows and shorter length straight pipe
employed in high pressure steam generators.
BACKGROUND OF THE OPERATION
During manufacturing of Tees for high pressure steam generators the edges of the
Tees are to be made to the standard profile for better weld deposition during welding. The
profile can be varied according to the material composition and thickness of the Tees.
Generally the profile machining can be done in the horizontal boring machine. The
fixing of Tees in the horizontal boring is time consuming and all the three faces are to be
made profile machining. The limitation in the depth of cut is also only 3.5mm whereas the
thickness of the Tees varies between 32 and 90mm with outside diameter varying from
273mm to 550mm depending on the components required in the high pressure steam
generators.
There are profile cutting machines available where the depth of cut is maximum 8 mm
and the time required is only one fourth than that of horizontal boring machine. Such
machines are named as SAFOP machines where we can get better quality of profile machining
than horizontal boring machine. Therefore we need a device and method of holding the tees,
shorter arm elbows, shorter length of straight pipes other than the conventional methods of
holding the job fixing in the special machines.

OBJECTS OF THE INVENTION
Therefore, it is an object of the invention to propose a method of profile machining in
high thickness pipe materials to fabricate tees, shorter arm elbows, shorter length
straight pipe employed in high pressure steam generator which is capable of
eliminating the time consuming method of prior art and increase productivity.
Another object of the invention is to propose a method of profile machining in
high thickness pipe materials to fabricate tees, shorter arm elbows, shorter length
straight pipe employed in high pressure steam generator with a device for holding the
job so that accurate profile can be machined for better welding.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 : Shows vertical clamping plate according to the invention.
Fig. 2 : Shows connecting 'V' blocks according to the invention.
Fig. 3 : Shows inside 'V' blocks according to the invention.
Fig. 4 : Shows 'V' clamps according to the invention.
Fig. 5 : Shows an isometric view of a holding device with 'elbow' as per
invention.
Fig. 6 : Shows the assembly of components with 'equal tee' as per
invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Accordingly, there is provided a method of profile machining in high thickness pipe
materials to fabricate tees, shorter arm elbow, shorter length straight pipe employed in
high pressure steam generators, the method as shown in Fig. 5 and 6 comprising the steps
of : placing the tee vertically in between vertical plates (01) by means of V blocks (03)
conveniently provided inside the vertical plates (01) and in between tee and vertical plate
so that the vertical and horizontal movements are arrested. There are drilled holes
available made by experimentation to suit different diameters of tee varying from 273mm
to 550mm and the fasteners are used to tightened the V blocks (03) with vertical plates
(01). The connecting 'V' blocks (02) are provided outside the vertical plate with fasteners
to connect the entire assembly in the two opposite jaws of profile machine (not shown).
According to the present invention, the machining operation is carried out in two
stages. In the first stage the work piece (05) referring to figure 5 one side profile
machining is carried out by placing the entire assembly in between the jaws of profile
cutting machine.
The invention relates to a method of profile machining on the both ends of the elbows,
tees and shorter length of low alloy steel pipes having high thickness used for high
pressure and ultra high pressure steam generators. The novel holding method comprises
the steps of fixing the work piece (07,05) in between vertical clamping plates (01) and 'V'
blocks (03) and clamping the work piece with universal 'V' clamps (03) both horizontal and
vertical directions, whereas the whole assembly is fixed in the profile cutting machine jaw
by external universal 'V' blocks (02) which perfectly seats in the machine jaw and tightened
by 'L' clamps (04) through four numbers of circular rods (08) attached to the external 'V'
blocks (02). The job can be easily dismantled to machine the other end to complete the

operation. Now the work piece is ready for welding. The horizontal distance between
vertical clamping plates (01) is decided according to the outside diameter in the range of
273mm to 550mm with thickness variation of 32 to 90mm.
In the case of equal tee (07), referring to the figure 6, the machining operation is
carried out in three stages. Method of fixing and dismantling are one and the same as done
for elbow (05) as described above.
Figure 1 shows the clamping plate (01), having drill holes with various dimensions as
shown so as to fix the various radii of tees and elbows.
Figure 2 shows the connecting 'V' blocks. There are four numbers of this , where
necessary holes are provided to fit on the machine as well as on the vertical clamping plate
(01).
Figure 3 shows the six numbers of 'V' blocks attached to the vertical clamping plate
(01) and the important feature of this block is the possibility of rotating the 'V' block 360
degree and clamped according to the work piece location.
Figure 4 shows; four no. of these 'L' clamps (04) interconnects the entire assembly
shown in figure 5 to machine jaw (not shown).
Figure 5 and 6 shows the work piece (05) and (07) in position which is ready for
machining operation. All the degrees of freedom are arrested by fixing the 'V' blocks (03)
intact with job (05 or 07) and the vertical clamping plate (01) and these are tightened by
fasteners (06) where as the external 'V' blocks (02) perfectly fixed on the machine jaws
(not shown) and the 'L' clamp (04) is used to interconnect the invented device with
machine jaw and profile machining operation can be carried out easily with more depth of
cut up to 8mm instead of 3.5mm in the conventional machine and the machining operation
time can be substantially reduced to 2 hours instead of 8 hours per side.

We Claim:
1. A method of profile machining in high thickness pipe materials to fabricate tees, shorter
arm elbows, shorter length straight pipe employed in high pressure steam generators, the said
method comprising the steps of;
placing the equal tee (07) or elbow (05) in any position in between the vertical
clamping plates (01) and 'V' blocks (03);
clamping the work piece with universal 'V' clamps (03) both horizontal and vertical
directions tightening the work piece with alien screws (06);
fixing the work piece assembly in the profile cutting machine jaw by external universal
'V' blocks (02) seating perfectly in the machine jaw; wherein the assembly is tightened by L
clamps (04) through horizontal circular rods (08) attached to the external 'V' blocks (02) to
make the work piece ready for machining when the machining operation is carried out with a
depth of cut of 8mm.
2. A method as claimed in claim 1, wherein six numbers of 'V' blocks (03) attached to the
vertical clamping plate (01) is rotatable for 360 degrees to facilitate clamping of the work
piece according to the location.
3. A method as claimed in claim 1, wherein the machining operation is carried out for
different diameters of tee varying from 273mm to 550mm with thickness variation of 32 to
90mm.
4. A method as claimed in claim 1, wherein four numbers of 'L' clamps (04) are employed
to interconnect the entire assembly.

ABSTRACT

The invention relates to a method of profile machining on the both ends of the elbows,
tees and shorter length of low alloy steel pipes having high thickness used for high pressure
and ultra high pressure steam generators. The novel holding method comprises the steps of
fixing the work piece (07,05) in between vertical clamping plates (01) and 'V' blocks (03) and
clamping the work piece with universal 'V' clamps (03) both horizontal and vertical directions,
whereas the whole assembly is fixed in the profile cutting machine jaw by external universal
'V' blocks (02) which perfectly seats in the machine jaw and tightened by 'L' clamps (04)
through four numbers of circular rods (08) attached to the external 'V' blocks (02). The job
can be easily dismantled to machine the other end to complete the operation. Now the work
piece is ready for welding. The horizontal distance between vertical clamping plates (01) is
decided according to the outside diameter in the range of 273mm to 550mm with thickness
variation of 32 to 90mm .