FIELD OF THE INVENTION

This present invention relates to a device for inserting a threaded insert in a threaded
hole of valve casing of supercritical steam turbine governing system.
BACKGROUND OF THE INVENTION
Steam turbine governing system consists of various valve casings which are very critical
components as the steam flows through these valve casings to different steam turbine
cylinders. Measurement inserts are usually fitted inside the threaded holes of valve
casing for measurement of different operating parameters such as pressure,
temperature and other process parameters. Due to high operating parameters of steam
turbine and repetitive opening and tightening of the measurement inserts, the threaded
hole in the valve casings tend to get damaged.
A threaded insert is a coiled helix; in general it's a coiled spring having a special tang at
end. The threaded insert is inserted in a threaded hole of the valve casing of
supercritical steam turbine governing system to prevent the damage of the threaded
holes during repeated tightening/untightening of the measurement inserts.

OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose a device for inserting a
threaded insert in a valve casing of supercritical steam turbine governing system.
Another object of the present invention is to propose a device for inserting a threaded
insert in a valve casing of supercritical steam turbine governing system, which is
enabled to securely hold and guide the threaded insert for inserting in the valve casing.
A still another object of the present invention is to propose a device for inserting a
threaded insert in a valve casing of supercritical steam turbine governing system, which
is portable and light in weight and rigid enough to sustain the loads.
A further object of the present invention is to propose a device for inserting a threaded
insert in a valve casing of supercritical steam turbine governing system, which securely
tightens the threaded insert inside the threaded hole of he valve casing and can be
removed easily.
SUMMARY OF THE INVENTION
The device of the invention is capable to hold securely he threaded insert end and then
rotated in such a manner that threaded inset expands towards its longitudinal axis.
Continuous rotation of the device in this manner guides and finally tightens the
threaded insert inside the threaded hole.

BRIEF DESCRIPION OF THE ACCOMPANYING DRAWINGS
Figure 1 - shows the device of the invention.
Figure 2 - shows a threaded insert for inserting into a valve casing.
Figure 3 - shows the threaded insert with the device.
Figure 4 - shows the device with the measurement insert.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 shows the device for inserting a threaded insert in valve casing of steam
turbine governing system according to the present invention which comprises :-
a Handle (1); and
a Device body (2) having a guide groove and a slot.
The body (2) of the device has a diameter D1, guide groove diameter D2, guiding
length L1 and shank diameter D3. On diameter D1 there is a slot width H1 and depth
H2 to firmly secure the tang of the threaded insert. Handle (1) having diameter D5 is
attached to the body (2) by a though hole D4 and can easily slide in the hole. The
handle is provided in such a manner that the device can be easily rotated by hand.

Figure 2 shows a threaded insert which is to be inserted and tightened inside a
threaded hole (H3) of the valve casing. It has outer diameter D7, minor diameter D6
and overall length 12. The threaded insert also has a tang, and a notch at the end to
break the tang after it is fully tightened. Also shown a measurement insert having guide
diameter D8 which guides inside the threaded insert.
Figure 3 shows the assembly of the threaded insert and the device such that the device
is rotated and guides the threaded insert inside the threaded hole of the valve casing
according to the embodiment of the present invention.
Figure 4 shows the measurement insert and threaded insert assembled inside the
threaded hole of the valve casing.
The threaded insert (see figure 2) having outer diameter D7 and minor diameter D6 is
assembled with the device (see figure 3) such that the groove diameter D2 on the
device guides and securely hold the outer diameter D7 of the threaded insert. A slot
having width H1 and height H2 is provided in the bottom of the device to capture and
securely hold the tang of the threaded insert. Its main function is to provide the
required torque to the threaded insert during insertion inside the threaded hole H3. Slot
height H2 is kept greater than the difference of L1 and L2 to initially accommodate the
threaded insert on the device body.
The complete assembly is then placed and aligned to the centre axis of threaded hole
H3 of the valve casing (see Figure 3) and then the device is rotated through the handle
(1) such that when it is rotated, the threaded insert expands longitudinally and gets
tightened inside the threaded hole.

During tightening of the threaded insert, the threaded insert expands towards its
longitudinal axis and the inner diameter of the threaded insert contracts, so diameter
D1 of device should be less than the minor diameter D6 of the threaded insert.
When the threaded insert reaches to bottom of the threaded hole H3 of depth L3 (see
Figure 3), the tang of the threaded insert (see Figure 3) is broken by a pliar and the
threaded insert gets properly tightened inside the threaded hole (3) and the device is
taken out.

WE CLAIM :
1. A device for inserting a threaded insert in a valve casing of supercritical steam
turbine governing system, the valve casing having a threaded hole H3 in which
the threaded insert being inserted, the measurement insert having a guide
diameter D8 which guides the threaded insert inside the threaded hole H3, the
threaded insert having an outer diameter D7, a minor diameter D6, an overall
length L2, a tang, and a notch at the end of the insert to break the tang after the
threaded insert is fully tightened inside the threaded hole H3, the device
comprising :
a body (2) having a body diameter D1, a guide groove diameter D2, a
guiding length L1, a shank diameter D3, wherein the body (2) comprising
a slot having width H1 and depth H2 to firmly secure the tang of the
threaded insert; and
a handle (1) having a diameter D5 slidably attached to the body (1) by a
through hole D4.
wherein the device is assembled with the threaded insert such that the groove diameter
D2 securely hold the outer diameter D7 of the threaded insert, wherein he slot of the
device holds the tang to provide required torque upon rotating the handle (1) which
allows the threaded insert to longitudinally expand and gets tightened inside the threaded
hole H3.

2. The device as claimed in claim 1, wherein he body diameter D1 of the device is
less than the minor diameter D6 of the threaded insert.
3. The device as claimed in claim 1, wherein the device body and the handle
is made of hardened and tempered steel.
4. The device as claimed in any of the preceding claims wherein the device is
portable.