FIELD OF INVENTION:
The present invention generally relates to rigid and uniform clamping of
guide blade carriers during stress relieving in furnace.
More particularly, the present invention relates to development of universal
fixture for rigid and uniform clamping of varieties of guide blade carriers
during stress relieving in furnace to prevent any distortion, thus enhancing
improvement in quality.
BACKGROUND OF THE INVENTION:
Guide blade carriers are part of low pressure (LP) module of steam turbines
which consists of outer ring, inner ring and guide blades welded together.
The function of guide blade carriers is to give proper direction to steam
during operation of steam turbines. After welding there is requirement of
stress relieving at temperature of around 650 degrees centigrade in
furnace. So clamping of these carriers should be rigid enough to prevent
any distortion at high temperatures. At present there is no proper fixture
for clamping the guide blade carriers, stress relieving is done by simply
keeping the guide blade carriers on base plate and using simple clamps. In
absence of proper clamping arrangement, this result in distortion of job and
hence rework is required which is time consuming.

OBJECT OF THE INVENTION:
An object of the present invention is to provide a rigid universal
fixture for clamping of guide blade carriers of low pressure
steam turbine during stress relieving which eliminates the
disadvantages of the prior art.
Another object of the invention is to provide a universal
fixture for clamping of guide blade carries of low pressure
steam turbine during stress relieving which can
accommodate the different varieties of guide blade carrier.
An yet another object of the invention is to provide a
universal fixture for clamping of guide blade carriers of low -
pressure steam turbine during stress relieving which
enhances quality improvement by accurate alignment, rigid
clamping and prevention of rejection.
A further objection of the invention is to provide a universal
fixture for clamping of guide blade carriers of low pressure
steam turbine during stress relieving which reduces the
setting and clamping time of guide blade carriers before
stress relieving.

SUMMARY OF THE INVENTION:
Accordingly, there is provided a universal fixture (1) for clamping of guide blade
Carrier (17) of Low Pressure Steam Turbine during stress relieving in furnace
comprising mainly:
a) Base plate (7)
b) C-clamp & bolt (welded) (2)
c) Clamp (3)
d) Block & bolt (welded) (4)
e) Hexagonal Nut (5)
f) Locking Nut (6)
Guide blade carriers (17) are positioned on base plate (7) such that it is uniformly
clamped at 8 positions equally distributed by 16 no.'s each of (8 on one side)
of clamps (3), C-clamp & bolt (welded) (2) & block & bolt (welded) (4) on both
outer diameter and inner diameter of guide blade carriers respectively and
then locked by hexagonal nut (5) & locking nut (6).
C-clamp & bolt (welded) (2) and block & bolt (welded) (4) can be moved along the
frame to accommodate different sizes of guide blade carriers.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Fig.l (a) (see sheet no.l) shows universal fixture (1) for stress
relieving of guide blade carrier (17) of Low Pressure Steam Turbine
according to present invention.
Fig. 1(b) (see sheet no.2) shows section-AA of fig.l (a) with base
plate (7), C-clamp & bolts (welded) (2), clamps (3), block & bolts
(welded) (4), hexagonal nuts (5) and locking nuts (6). Diameter D3
& diameter D4 are outer diameter & inner diameter of guide blade
carrier (17) respectively.
Fig.2(a) (see sheet no.3) shows of universal fixture (1) for stress
relieving shown in fig.l (a) & fig.l (b) which is a fabricated structure
(1) comprising of base plate (7), plurality of I-beams (8), plurality of
I-beams (9), and 4 no.'s of lifting lugs (10) according to embodiment
of present invention.
Fig. 2(b) (see sheet no.4) shows the Section -BB & Section -CC of
Fig. 2(a) according to present invention.

Fig.3(a) (see sheet no.5) shows C-clamp & bolt (welded) (2) which
comprises of c- clamp (13) and threaded headless bolt (14) having
diameter HI welded together . The depth of c- clamp (13) is T3 and
width T4 according to an embodiment of the present invention.
Fig. 3(b) (see sheet no.5) shows block & bolt (welded) (4) which
comprises of a rectangular block (15) and threaded headless bolt (16)
having threaded diameter H3 welded together according to present
invention.
Fig.4(a) & Fig.4(b) (see sheet no.6) shows Clamp (3) having hole H4
and Lifting lug (10) having lifting hole H5 according to an embodiment
of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE PRESENT
INVENTION:
Fig.l (a) (see sheet no.l) & Fig.l (b) (see sheet no.2) shows the universal
fixture (1) which comprises of a base plate (7). Outer diameter Dl & Inner
Diameter D2 of base plate (7) are selected in such a way to accommodate
various guide blade carriers having different outer & inner diameters D3 & D4
respectively.
16 no.'s of c-clamp & bolt (welded) (2) are guided with plurality of I-beams (8)
so that they can be moved and adjusted according to different diameters of
guide blade carriers. Dimensions T3 & T4 (refer sheet no. 5) are selected in
such that they can accommodate the dimensions Tl & T2 (refer sheet no. 4)
respectively.
Guide blade carrier is rested on top plate (11) of universal fixture (1) and are
tightened by 16 no.'s (8 each side) of C-clamp & bolt (welded) (2) & clamps (3)
with holes "HI" & H4 through plurality of hexagonal nuts (5) on both outer
diameter and inner diameter. Then the 16 no.'s of clamps(3) are being
supported by equal no.'s of block & bolt (welded) (4) and locked by plurality of
locking nuts (6) with holes H3 & H4.
After proper tightening and alignment of guide blade carrier on fixture is done,
the whole system is then inserted inside the furnace for stress relieving
Fig.2(a) (see sheet no.3) shows universal fixture (1) for stress relieving shown
in fig.l (a) & fig.l (b) which is a fabricated structure comprising of

base plate (7) having outer diameter Dl & inner diameter D2, plurality of I-
beams (8), plurality of I-beams (9) and 4 no.'s of Lifting lugs (10) according to
embodiment of present invention.
Fig. 2(b) (see sheet no.4) shows the Section -BB & Section -CC of Fig. 2(a) . In
Section -BB top plates (11) are welded on top of plurality of I-beams (8) having
width Tl and total thickness T2. Top plates (11) provide the accurate machined
surface for resting of guide blade carriers (17). In Section-CC plates (12) are
welded on top of plurality of I-beams (8&9) at their ends.
Fig.3(a) (see sheet no.5) shows C-clamp & bolt (welded) (2) which comprises
of C- clamp (13) and threaded headless bolt (14) having diameter HI welded
together . The depth of C- clamp (13) is T3 and width T4 according to an
embodiment of the present invention. Depth T3 & T4 should be carefully
chosen to accommodate Tl & T2 respectively. Also total length & threaded
length of c-clamp & bolt (welded) (2) are chosen to accommodate different
heights of guide blade carriers accordingly.
Fig.3 (b) (see sheet no.5) shows block & bolt (welded) (4) which comprises of a
rectangular block (15) and threaded headless bolt (16) welded together having
threaded diameter H3 according to present invention. Total length & threaded
length of block & bolt (welded) (4) are chosen to accommodate different
heights of guide blade carriers accordingly.

Fig.4(a) & Fig.4(b) (see sheet no.6) shows clamp (3) having hole H4 and
Lifting lug (10) having lifting hole H5 according to an embodiment of the
present invention.

We Claim:
1. A universal fixture (1) for clamping of guide blade carrier (17) of low pressure
steam turbine during stress relieving comprises:
a base plate (7);
a plurality of I-beams (8) directed diametrically in outward direction and I- beams (9)
in circumferential direction welded on to the base plate (7); a plurality of plates (11)
welded over I beams (8) having machined surface on top for resting of guide blade
carrier (17);
a plurality of plates (12) welded over I-beams (9) arranged in the circumferential
direction;
a combination of C-clamp and bolt (2), clamp (3) and block and bolt (4) mounted on
the I-beam shoulder, characterized in that,
the inner dimension of C-clamp in C-clamp and bolt (2) and the outer dimension of I-
beam shoulder (8) are such that the C-clamp and Bolt (2) can slide over I block
shoulder (8) according to various sizes of guide blade carrier (17) for holding the job
with the help of combination of C-clamp and bolt (2), block and bolt (4) and clamp-3
where the hexagonal nut (5) and locking nut (6) grips the job rigidly at required
height.
2. The device as claimed in claim 1 wherein the distribution of I-beams (8) and (9)
are arranged and welded in a manner to give rigidity during clamping to avoid any
type of distortion during stress relieving.
3. The device as claimed in claim 1 wherein the C-clamp (13) is welded to bolt (14)
to form C-clamp and bolt (2).
4. The device as claimed in claim 1 wherein the block (15) is welded to bolt (16) to
form block and bolt (4).

5. The device as claimed in claim 1 wherein the base plate (7), C-clamp a bolt
(welded) 2 and block a bolt (welded) 4 are designed suitably to accommodate
different sizes of guide blade carrier (17).
6. The device as claimed in claim 1 wherein the hexagonal nut (5), locking nut (6),
C-clamp (13), bolt (14), block (15) and bolt (16) are made of high temperature alloy
steel to prevent any distortion.
7. The device as claimed in claim 1 wherein the frame (1) is suitably designed
according to the dimension of the furnace.
8. The device as claimed in claim 1 wherein the lifting lug (10) is designed to bear
the weight the fixture and guide blade carriers.

ABSTRACT

1. A universal fixture (1) for clamping of guide blade carrier (17) of low pressure steam turbine during stress relieving comprises: a base plate (7); a plurality of I-beams (8) directed diametrically in outward direction and I- beams (9) in circumferential direction welded on to the base plate (7); a plurality of plates (11)
welded over I beams (8) having machined surface on top for resting of guide blade carrier (17);
a plurality of plates (12) welded over I-beams (9) arranged in the circumferential direction;
a combination of C-clamp and bolt (2), clamp (3) and block and bolt (4) mounted on the I-beam shoulder, characterized in that, the inner dimension of C-clamp in C-clamp and bolt (2) and the outer dimension of I- beam shoulder (8) are such that the C-clamp and Bolt (2) can slide over I block shoulder (8) according to various sizes of guide blade carrier (17) for holding the job with the help of combination of C-clamp and bolt (2), block and bolt (4) and clamp-3
where the hexagonal nut (5) and locking nut (6) grips the job rigidly at required height.