FIELD OF INVENTION
The present invention relates to a method of manufacturing header
pipes/links for boilers with counter weight assembly fixed on the pipe for uniform
rotation during sub merged Arc Welding process.
BACKGROUND OF THE INVENTION
In the manufacturing of super heaters for high pressure boilers, the
outside diameter of the pipe is 508mm with thickness 70mm and other pipes
having outside diameter 558mm having thickness 70mm. The other ranges are
dia 660 x 40mm and dia 711x47mm. These pipes are SA 335 P91 materials.
Different kind of "links" (Joining of straight pipe with bend pipes) are to be
made with same diameter and same thickness of the pipes to form inlet and
outlet of super heaters for high pressure and ultra high pressure boilers. The
joints are to be made with a suitable welding process. While connecting two
pieces in auto welding machine will not be a problem but the third piece
connection in the auto welding machine creates jerking and sudden fall down of
work pieces due to imbalance and thereby the welding is not proper and causes
defects like gouging and grinding the weldment already made and again the
welding process is to be carried out. The weight of the link varies from 2 tons to
maximum of 5 ton per assembly to be handled with crane only. Hence this
problem needs to be sorted out by inventing a new method of fixing the job
while welding. Alternatively the manual weld substantially involves more time to
complete the job and involves a lot of material handling. The weld quality is also
not upto the standard. Hence there is a need to find a new method of handling
the work piece to do the jobs as shown in Figure 1.

PRIOR ART:
US8523226B2
Disclosed is a counterweight which is filled with a heavy weight concrete
containing, instead of currently used iron ores, a heavy-weight aggregate that
scarcely causes the material segregation from cement paste and which can be
produced at a low cost and is effectively enhanced in the filling factor of heavy-
weight concrete into a case. A counterweight 6 comprises a case 62 and heavy-
weight filled therein, wherein the heavy-weight concrete contains a heavy weight
fine aggregate containing 20 mass % or more or aggregate particles having
particle diameters of less than 0.15mm and 20 mass % or more of aggregate
particles having particle diameters of 2.5mm to less than 5mm.
JP2013147336
When renewal of an elevator, a new form of balancing weight is small
even if the existing weight blocks to reuse the existing weight blocks.
The weight of the elevator, and a pair of left and right vertical frame
comprising a pair of upper and lower horizontal frame and frame balancing
weight, either of a pair of horizontal frame rotatably coupled to the balancing
weight and sheave, the lateral width of the frame is formed with a width,
balancing weight loaded on the inside of the frame 1 and the second weight
block , the second weight block 1 formed with a width smaller than the width,
and a balance weight of the second weight block 1 on the inside of the frame 2
and the second weight block, the width of the first and second weight blocks 21
of the weight of a dimension corresponding to the difference in the width of the

block are formed, respectively, on a pair of vertical frames are connected, the
second weight block 2 of a balance weight fixed to the inside of a frame and a
pair of fixing, is provided.
Search conducted and it has been found that above inventions are not
relevant to this patent application even though counter weight has played a role.
OBJECTS OF THE INVENTION
Therefore, it is an object of the invention to propose a method of
manufacturing header pipes/links for boilers with counter weight assembly (W)
fixed on the pipe for uniform rotation during sub merged Arc Welding process
which is capable of providing an uniform rotation of the pipe during welding.
Another object of the invention is to propose a method of manufacturing
header pipes/links for boilers with counter weight assembly (W) fixed on the pipe
for uniform rotation during sub merged Arc Welding process which is capable of
arresting jerking during welding to result smooth and defect free welding.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 : Shows the different links / header pipes assembly according to the
invention.
Fig. 2 : Shows the counter weight assembly as per invention.
Fig.3 : A typical link with counter weight in a particular position in
accordance with the invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
Accordingly, there is provided a counter weight (W) which is fixed on the
longer arm side of the pipe with left-right combination. This method is having
counter weight assembly (W) comprising of heavy thickness of pipe (01),
solid block (02), difference plate, spring washer (09) with necessary clamps
(07) and lifting hook (03) with holes for hoisting purpose. The assembly is
also having suitable clamps and fasteners. By calculating the weight of the
job on the rotor body of the welding machine, suitable solid block (02) and
heavy thickness pipes (01) are added together by conventional welding
process and inserted in the longer arm of the job which is to be inserted and
clamped with necessary clamps and fasteners so that uniform rotation is
achieved without jerking and fallout to carry out complete welding process.
According to the present invention, the welding operation is carried out
with uniform rotation for the work piece. The required counter weight is
found by calculating the weight of the job which is to be fixed on the rotor
part. The necessary heavy thickness pipe (01) and solid block (02) are
selected based on the weight of the job arrived.
The distance of the counter weight (W) is determined based on the
experiments and settings and it has been found that 1.5D from the joint of
the work piece is suitable where D is the outside diameter of the pipe in
millimeter and the position is 180deg opposite to the joint. In the case of the
higher thickness of the pipes, the horizontal distance of 1.5 D shall not be
less than 1.5 metre so that the welding torch will not be a hindrance to the
counterweight. Now the uniform rotation is confirmed and the auto welding is
carried out without any rework and rejection.

Figure 1 shows the combination of links/header pipes as detailed below:
(a) Two elbows with three straight pipes.
(b) Two 45deg bends with two straight pipes.
(c) Two elbows with two straight pipes.
(d) Two elbows, three straight pipes, one equal tee and one reducer.
(e) One straight pipe, one elbow and one reducer.
Figure 2 shows the assembly which is going to be fixed on the work piece
(11) is explained below:
Heavy thickness pipe (01) is welded with solid block (02). The lifting hook
(03) is welded with solid block (02) and the hole (04) is provided in the lifting
hook (03) to handle the counter weight assembly (W).
To provide strength and stiffness necessary stiffener plates (05) are
welded to the heavy thickness pipe (01).
The top clamp (06) is welded with heavy thickness pipe (01) and stiffness
plates (05).
The radius of the top clamp (06) and bottom clamp (07) are so designed
to suit the various diameter of the super heater links out side diameter from
508 mm to 711 mm.
The top clamp (06) and bottom clamp (07) are positioned by means of
bolt (10) and nut (08) and spring washer (09).
The spring washer (09) endures the tightness of the assembly during
rotation and heating involved in the process.
Referring to figure 2 and 3 the above said assembly is fixed on the work
piece (11) and the top clamp (06) and the bottom clamp (07) is connected
and positioned by means of hexagonal bolt (10), nut (08) and the spring

washer (09) is used in between nut (08) and top clamp (07) to ensure the
tightness during pre heating and welding time. This spring washer (09)
ensures the safety of the assembly during the SAW process welding. The
already connected portion of other work pieces (12) and (13) are inserted in
the rotor assembly. The work pieces (11), (12) & (13) are uniformly rotated
without jerking and SAW process is carried out automatically to connect the
elbow (15) and straight pipe (14). After successful completion of joint (16)
and the counter weight assembly is shifted to near the joint (17) and the full
weld is completed for the joint (17).
In the similar manner, the work piece (b), (c), (d) and (e) of Figure 1
are completed with this counter weight device for smooth welding of joints.

We Claim:
1. A method of manufacturing header pipes/links for boilers with counter weight
assembly (W) fixed on the pipe for uniform rotation during sub merged Arc Welding
process, the said method comprising;
welding a heavy thickness pipe (01) with a solid block (02);
welding welded pipe (01) and block (02) with lifting hook (03) having lifting hole
(04) to handle the counter weight assembly (W);
welding a plurality of stiffener plates (05) to the heavy thickness pipe (01) to
provide strength and stiffness necessary;
welding top clamp (06) with heavy thickness pipe (01) and stiffener plate (05);
fixing the above assembly on the workpiece (11);
clamping the workpiece (11) with bottom clamp (07) and top clamp (06) by
means of hexagonal bolt (10), nut (08) and spring washer (09) ensuring the tightness
and safety during preheating and welding time; wherein already connected portion of
otherwork pieces (12) and (13) are inserted in the rotor assembly when the work pieces
(11),(12) and (13) are uniformly rotated without jerking while the welding is carried out
automatically to connect the elbow (15) and straight pipe (14) wherein the counter
weight assembly (W) is shifted to joint (17) after completion of joint (16) to weld joint
(17) full and complete when the workpieces (b),(c),(d) and (e) are completed with this
counter weight device for smooth welding of joints.
2. The method as claimed in claim 1, wherein the radius of the top clamp (06) and
bottom clamp (07) are made to suit the various diameter of the super heater links
outside diameter from 508mm to 711mm.
3. The method as claimed in claim 1, wherein the distance of the counter weight is
maintained at 1.5D from the joint of the work piece where D is the outside diameter of
the pipe and is positioned at 180 degree opposite to the joint.

ABSTRACT

A method of welding links (super heater pipes) in submerged Arc welding
automatic machine using counter weight assembly comprises of welding a heavy
thickness pipe (01) with a solid block (02) and welding the pipe (01) and block
(02) with lifting hook (03) having lifting hole (04) to handle counter weight
assembly. A plurality of stiffener plates (05) are welded to the heavy thickness
pipe (01) to provide strength and stiffness. The top clamp (06) is welded with
heavy thickness pipe (01) and stiffness plate (05). The above assembly is fixed
on the workpiece (11) and clamped with hexagonal bolt (10), nut (08) and
spring washer (09). The already connected portion of other workpieces (12) and
(13) are then uniformly rotated without jerking when the welding is carried out
automatically to connect elbow (15) and straight pipe (14). After necessary
completion of joint 16, the counter weight assembly is shifted near to the joint
17 to perform the welding. Accordingly, the work pieces (b), (c), (d) and (e) are
completed with this counter weight device for smooth welding of joints.