Title of Invention	A METHOD FOR DETECTION OF DEFECTS DURING WELDING BY ULTRASONIC TESTING
Abstract	The invention relates to a method of on-line detection and control of defects forming in an object during a welding operation, comprising the steps of providing an ultrasonic testing system having multiple transducers (6,7,8),the transducers (6,7,8) being movable in correspondence with the movement of a welding torch; transmitting a first ultrasonic sound wave (4) via a first transducer (6) directed to an unwelded area (9) of the object; transmitting a second ultrasonic sound wave (4) via a second transducer (7) directed to a molten pool (10); transmitting a third ultrasonic sound wave (4) via a third transducer (8) to a just-solidified part (11) of the weld; capturing the sound waves reflected from the three different areas (9,10,11) in the respective transducers (6,7,8) from which the ultrasound waves (4) were initially transmitted, the reflected signals representing the defects or discontinuities prevailing or developing in the corresponding areas (9,10,11); characterized by comprising converting the captured sound signals into electric signals and displaying the electric signals in respective display devices (13,14,15), the display devices (13,14,15) each having echo indicators (12,16,17); comparing the electric signals with the echo indicators (12,16,17) in the display devices (13,14,15) to determine the magnitude of defects or discontinuities; and adjusting the welding parameters corresponding to the detected defects to avoid formation of further defects, wherein a positional value (W2) of the echo-indicator (17) at the display device (15) if greater than that (WI) of the echo-indicator (12) at the display device (13), the resultant weld is considered to be defect-free.

Title of Invention

A METHOD FOR DETECTION OF DEFECTS DURING WELDING BY ULTRASONIC TESTING

Abstract

The invention relates to a method of on-line detection and control of defects forming in an object during a welding operation, comprising the steps of providing an ultrasonic testing system having multiple transducers (6,7,8),the transducers (6,7,8) being movable in correspondence with the movement of a welding torch; transmitting a first ultrasonic sound wave (4) via a first transducer (6) directed to an unwelded area (9) of the object; transmitting a second ultrasonic sound wave (4) via a second transducer (7) directed to a molten pool (10); transmitting a third ultrasonic sound wave (4) via a third transducer (8) to a just-solidified part (11) of the weld; capturing the sound waves reflected from the three different areas (9,10,11) in the respective transducers (6,7,8) from which the ultrasound waves (4) were initially transmitted, the reflected signals representing the defects or discontinuities prevailing or developing in the corresponding areas (9,10,11); characterized by comprising converting the captured sound signals into electric signals and displaying the electric signals in respective display devices (13,14,15), the display devices (13,14,15) each having echo indicators (12,16,17); comparing the electric signals with the echo indicators (12,16,17) in the display devices (13,14,15) to determine the magnitude of defects or discontinuities; and adjusting the welding parameters corresponding to the detected defects to avoid formation of further defects, wherein a positional value (W2) of the echo-indicator (17) at the display device (15) if greater than that (WI) of the echo-indicator (12) at the display device (13), the resultant weld is considered to be defect-free.

Full Text	FIELD OF INVENTION The invention relates to a system for testing a weld to detect the post-weld defects using an ultrasonic test device. More particularly, the invention relates to a system and method of on-line detection of defects-forming in a welding operation and allow adjustment of the operational parameters for avoidance of further development of defects. BACKGROUND OF INVENTION Ultrasonic testing is a well-established non-destructive testing method for evaluating the quality of raw material, semi-finished and finished products. The method is well established for testing a weld when the welding operation is completed fully. According to the prior art testing method, after completion of the welding operation, a transducer of the ultrasonic testing device, is moved over the object with full contact. The ultrasound generated through the transducer of the device is transmitted into the object at an angular or at a direction normal to the job-surface. If there remains any discontinuity in the welded object, the ultrasound is reflected from the discontinuity which acts as the reflection medium. The reflected ultrasound waves is picked up by the same transducer, and the acoustic signals are converted to electrical signals. The acquired electric signal is amplified by an amplifier and displayed in a display means for example, a cathode ray tube or an LCD screen. Thus, the presence of the signal indicates the presence of the discontinuity. The transducer is then moved laterally in a to-and-fro manner to identify the location of the discontinuity in the weld. The existing testing method is conducted when the weld is fully completed and at ambient temperature. US 6125 705 discloses a weld-test method which utilizes at least two transducers for detecting the weld defects in the partially or fully welded condition. The transducers are placed on either side of the weld and tested after the welding is completed. The testing also requires that the probes be moved laterally or front or back. The proposed patent employs three transducers and are positioned so that the first acquires signal from the unwelded area, the second acquires signal from the weld pool, the third from partially completed weld region simultaneously and displayed either simultaneously superimposed and / or individually displayed for interpretation manually. Patent US 6532820 describes a methodology wherein ultrasonic testing is conducted from both sides of the weld and combines with the information from position sensors to build up an image of the defect in a weld. US2001052264 discloses a testing method in which the transducer is moved in a lateral way using a motorized system and studying the weld for flaws. US4712722 discloses a system for studying weld slightly behind the molten pool. The reflected signals are anlysed using computer based digital pattern recognition techniques. US 6125705 describes a method for UT of a weld from both sides slightly behind the weld molten pool. The reflected signals from both sides are analysed and flaws identified. If the flaws are beyond acceptable levels then the feed back is provided to the welding machine to stop the weld. -S- However, none of the existing art provides a system and method of on-line detection of defect-forming so as to correspondingly control the welding parameters to eliminate the further defects. SUMMARY OF INVENTION The present invention provides a system and method for testing the weld during welding. The formation of the defects can be identified as and when the defect is formed and can be used for providing feedback to control the weld parameter to avoid continuance of the defect formation. It can allow the repair of the defect as soon as it starts forming without waiting for the weld to be completed fully. It eliminates the requirement for weld profile smoothening for easier interpretation of signals during the post weld testing. The method can be used for identifying vertical defects in narrow gap welding processes, lack of penetration at the root in the single and double sided welding process. This method can further be also applied when the weld is not in progress, particular in the case of double sided joints where the root is to be back gouged, or back grounded, the confirmation of the removal of defects in the root pass is ensured. The present invention uses multiple transducers, preferably three, so that each transducer is injecting the sound at different parts of the weld. The sound reflected from the welded area, weld molten area, weld molten pool, and the unwelded area from the prior weld bead reflections from the bead or a defect is received in the same transducers. The method is especially applicable for the narrow gap welding processes for finding lack of fusion defects as and when they are formed. The method is also applicable for the double sided weld for detecting the lack of penetration in the root. The method is further applicable for the single sided weld for detecting the lack of penetration in the root. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Figure 1 - shows a prior art method of testing a weld after the weld is completed. Figure 2 - shows the arrangement for testing the weld during welding operation according to the present invention. Figure 3 - shows the probe position, sound path and the echo pattern according to the invention. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF INVENTION As shown in figure 1, the transducer (1) is moved over the object (2) with full contact, so that the ultrasound (4) generated by the transducer is transmitted into the object at an angle or normal to the job surface. The discontinuity (3), if present, acts as a reflection medium and the reflected ultrasound is picked up by the same transducer (1) and the sound is converted to an electric signal. The electrical signal so obtained is amplified by an amplifier and the signal is displayed in a display device-usually a cathode ray tube or an LCD screen. Thus, the presence of the signal indicates the presence of the discontinuity. The transducer is moved in a to-and-fro lateral direction (5) and checked if a defect is present at any part of the weld (6). The method is applicable for all the fusion welded objects, and herein illustrated with an example of a plate (1). The method comprises injecting ultrasonic sound waves (4) into the weldment using multiple transducers (6, 7, 8). The first transducer (6) directs the sound from a first probe in the unwelded portion (9) of the weld (6), the sound from a second probe via a second transducers (7) is directed at the molten pool (10), and sound from a third transducer (8) is directed towards a solidified area (11). The system is shown in figure 2. The system is moved along with the welding torch such that the above activities of the transducers (6, 7, 8) is maintained. When the welding is started, the first transducer (6) injects an ultrasound (4) towards the unwelded area (9) and that unwelded surface (9) reflects the ultrasound (4) and a first display device (13) of the system indicates that the position of the echo in the unmelted area before the start of welding. At the same time, the second transducer (7) injects an ultrasound (4) toward the molten pool (10) and a second display (14) indicates the nature of sound reflected. The third transducer (8) injects an ultrasound (4) towards the area which has just solidified (11). A third display (15) displays the echo, and from the display, the nature and the position of the reflector can be assessed. If the defects are being formed then it can be deduced from the display. As shown in figure 3, if the position of the echo indications (12) in display (15) is W2, then (W2 - Wl) should be positive value to indicate a good weld. The nature of echo (16) in display (14) indicates if a defects is being formed. The pattern of the echo (17) indicates the presence or absence of any defect. The system is periodically and suitably cooled and shielded to ensure that the transducers (6, 7, 8) are not heated up. Figures 3(a), 3(b), 3(c) shows the beam path and echo pattern (16) when the transducer (7) respectively inject sound before the molten pool (10) before the weld is undertaken, before the weld zone and after the weld is solidified. We Claim: 1. A method of on-line detection and control of defects forming in an object during a welding operation, comprising the steps of: - providing an ultrasonic testing system having multiple transducers (6,7,8),the transducers (6,7,8) being movable in correspondence with the movement of a welding torch; - transmitting a first ultrasonic sound wave (4) via a first transducer (6) directed to an unwelded area (9) of the object; - transmitting a second ultrasonic sound wave (4) via a second transducer (7) directed to a molten pool (10); - transmitting a third ultrasonic sound wave (4) via a third transducer (8) to a just-solidified part (11) of the weld; - capturing the sound waves reflected from the three different areas (9,10,11) in the respective transducers (6,7,8) from which the ultrasound waves (4) were initially transmitted, the reflected signals representing the defects or discontinuities prevailing or developing in the corresponding areas (9,10,11); characterized by comprising: - converting the captured sound signals into electric signals and displaying the electric signals in respective display devices (13,14,15), the display devices (13,14,15) each having echo indicators (12,16,17); - comparing the electric signals with the echo indicators (12,16,17) in the display devices (13,14,15) to determine the magnitude of defects or discontinuities; and - adjusting the welding parameters corresponding to the detected defects to avoid formation of further defects, wherein a positional value (W2) of the echo-indicator (17) at the display device (15) if greater than that (WI) of the echo-indicator (12) at the display device (13), the resultant weld is considered to be defect-free. 2. The method as claimed in claim 1, wherein the transducers (6,7,8) are periodically cooled during the on-line testing to avoid heating. 3. An ultrasonic testing system for carrying out the method as claimed in claims 1 and 2, comprising: - a plurality of transducers (6,7,8) capable of orientation and axial movement at different directions and transmitting ultrasonic sound wave (4), the transducers (6,7,8) being enabled to receive back the ultrasonic sound wave (4) when reflected from an object; and - a plurality of display devices (13,14,15) operably connected to the respective transducers (6,7,8) for indicating the reflected-echo parameters (12,16,17) of the ultrasonic sound signal (4) when converted from electric signals. ABSTRACT TITLE: A METHOD FOR DETECTION OF DEFECTS DURING WELDING BY ULTRASONIC TESTING The invention relates to a method of on-line detection and control of defects forming in an object during a welding operation, comprising the steps of providing an ultrasonic testing system having multiple transducers (6,7,8),the transducers (6,7,8) being movable in correspondence with the movement of a welding torch; transmitting a first ultrasonic sound wave (4) via a first transducer (6) directed to an unwelded area (9) of the object; transmitting a second ultrasonic sound wave (4) via a second transducer (7) directed to a molten pool (10); transmitting a third ultrasonic sound wave (4) via a third transducer (8) to a just-solidified part (11) of the weld; capturing the sound waves reflected from the three different areas (9,10,11) in the respective transducers (6,7,8) from which the ultrasound waves (4) were initially transmitted, the reflected signals representing the defects or discontinuities prevailing or developing in the corresponding areas (9,10,11); characterized by comprising converting the captured sound signals into electric signals and displaying the electric signals in respective display devices (13,14,15), the display devices (13,14,15) each having echo indicators (12,16,17); comparing the electric signals with the echo indicators (12,16,17) in the display devices (13,14,15) to determine the magnitude of defects or discontinuities; and adjusting the welding parameters corresponding to the detected defects to avoid formation of further defects, wherein a positional value (W2) of the echo-indicator (17) at the display device (15) if greater than that (WI) of the echo-indicator (12) at the display device (13), the resultant weld is considered to be defect-free.

Full Text

FIELD OF INVENTION
The invention relates to a system for testing a weld to detect the post-weld
defects using an ultrasonic test device. More particularly, the invention relates to
a system and method of on-line detection of defects-forming in a welding
operation and allow adjustment of the operational parameters for avoidance of
further development of defects.
BACKGROUND OF INVENTION
Ultrasonic testing is a well-established non-destructive testing method for
evaluating the quality of raw material, semi-finished and finished products.
The method is well established for testing a weld when the welding operation is
completed fully. According to the prior art testing method, after completion of
the welding operation, a transducer of the ultrasonic testing device, is moved
over the object with full contact. The ultrasound generated through the
transducer of the device is transmitted into the object at an angular or at a
direction normal to the job-surface. If there remains any discontinuity in the
welded object, the ultrasound is reflected from the discontinuity which acts as
the reflection medium. The reflected ultrasound waves is picked up by the same
transducer, and the acoustic signals are converted to electrical signals. The
acquired electric signal is amplified by an amplifier and displayed in a display
means for example, a cathode ray tube or an LCD screen. Thus, the presence of
the signal indicates the presence of the discontinuity. The transducer is then
moved laterally in a to-and-fro manner to identify the location of the
discontinuity in the weld.

The existing testing method is conducted when the weld is fully completed and
at ambient temperature.
US 6125 705 discloses a weld-test method which utilizes at least two transducers
for detecting the weld defects in the partially or fully welded condition. The
transducers are placed on either side of the weld and tested after the welding is
completed. The testing also requires that the probes be moved laterally or front
or back. The proposed patent employs three transducers and are positioned so
that the first acquires signal from the unwelded area, the second acquires signal
from the weld pool, the third from partially completed weld region
simultaneously and displayed either simultaneously superimposed and / or
individually displayed for interpretation manually.
Patent US 6532820 describes a methodology wherein ultrasonic testing is
conducted from both sides of the weld and combines with the information from
position sensors to build up an image of the defect in a weld.
US2001052264 discloses a testing method in which the transducer is moved in a
lateral way using a motorized system and studying the weld for flaws.
US4712722 discloses a system for studying weld slightly behind the molten pool.
The reflected signals are anlysed using computer based digital pattern
recognition techniques.
US 6125705 describes a method for UT of a weld from both sides slightly behind
the weld molten pool. The reflected signals from both sides are analysed and
flaws identified. If the flaws are beyond acceptable levels then the feed back is
provided to the welding machine to stop the weld.
-S-

However, none of the existing art provides a system and method of on-line
detection of defect-forming so as to correspondingly control the welding
parameters to eliminate the further defects.
SUMMARY OF INVENTION
The present invention provides a system and method for testing the weld during
welding. The formation of the defects can be identified as and when the defect is
formed and can be used for providing feedback to control the weld parameter to
avoid continuance of the defect formation. It can allow the repair of the defect
as soon as it starts forming without waiting for the weld to be completed fully. It
eliminates the requirement for weld profile smoothening for easier interpretation
of signals during the post weld testing.
The method can be used for identifying vertical defects in narrow gap welding
processes, lack of penetration at the root in the single and double sided welding
process.
This method can further be also applied when the weld is not in progress,
particular in the case of double sided joints where the root is to be back gouged,
or back grounded, the confirmation of the removal of defects in the root pass is
ensured.
The present invention uses multiple transducers, preferably three, so that each
transducer is injecting the sound at different parts of the weld.

The sound reflected from the welded area, weld molten area, weld molten pool,
and the unwelded area from the prior weld bead reflections from the bead or a
defect is received in the same transducers.
The method is especially applicable for the narrow gap welding processes for
finding lack of fusion defects as and when they are formed.
The method is also applicable for the double sided weld for detecting the lack of
penetration in the root. The method is further applicable for the single sided
weld for detecting the lack of penetration in the root.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 - shows a prior art method of testing a weld after the weld is
completed.
Figure 2 - shows the arrangement for testing the weld during welding operation
according to the present invention.
Figure 3 - shows the probe position, sound path and the echo pattern according
to the invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF
INVENTION
As shown in figure 1, the transducer (1) is moved over the object (2) with full

contact, so that the ultrasound (4) generated by the transducer is transmitted
into the object at an angle or normal to the job surface. The discontinuity (3), if
present, acts as a reflection medium and the reflected ultrasound is picked up by
the same transducer (1) and the sound is converted to an electric signal. The
electrical signal so obtained is amplified by an amplifier and the signal is
displayed in a display device-usually a cathode ray tube or an LCD screen. Thus,
the presence of the signal indicates the presence of the discontinuity. The
transducer is moved in a to-and-fro lateral direction (5) and checked if a defect is
present at any part of the weld (6).
The method is applicable for all the fusion welded objects, and herein illustrated
with an example of a plate (1). The method comprises injecting ultrasonic sound
waves (4) into the weldment using multiple transducers (6, 7, 8). The first
transducer (6) directs the sound from a first probe in the unwelded portion (9) of
the weld (6), the sound from a second probe via a second transducers (7) is
directed at the molten pool (10), and sound from a third transducer (8) is
directed towards a solidified area (11). The system is shown in figure 2.
The system is moved along with the welding torch such that the above activities
of the transducers (6, 7, 8) is maintained.
When the welding is started, the first transducer (6) injects an ultrasound (4)
towards the unwelded area (9) and that unwelded surface (9) reflects the
ultrasound (4) and a first display device (13) of the system indicates that the
position of the echo in the unmelted area before the start of welding.

At the same time, the second transducer (7) injects an ultrasound (4) toward the
molten pool (10) and a second display (14) indicates the nature of sound
reflected.
The third transducer (8) injects an ultrasound (4) towards the area which has
just solidified (11). A third display (15) displays the echo, and from the display,
the nature and the position of the reflector can be assessed. If the defects are
being formed then it can be deduced from the display.
As shown in figure 3, if the position of the echo indications (12) in display (15) is
W2, then (W2 - Wl) should be positive value to indicate a good weld. The
nature of echo (16) in display (14) indicates if a defects is being formed. The
pattern of the echo (17) indicates the presence or absence of any defect.
The system is periodically and suitably cooled and shielded to ensure that the
transducers (6, 7, 8) are not heated up.
Figures 3(a), 3(b), 3(c) shows the beam path and echo pattern (16) when the
transducer (7) respectively inject sound before the molten pool (10) before the
weld is undertaken, before the weld zone and after the weld is solidified.

We Claim:
1. A method of on-line detection and control of defects forming in an object
during a welding operation, comprising the steps of:
- providing an ultrasonic testing system having multiple transducers
(6,7,8),the transducers (6,7,8) being movable in correspondence with the
movement of a welding torch;
- transmitting a first ultrasonic sound wave (4) via a first transducer (6)
directed to an unwelded area (9) of the object;
- transmitting a second ultrasonic sound wave (4) via a second transducer
(7) directed to a molten pool (10);
- transmitting a third ultrasonic sound wave (4) via a third transducer (8) to
a just-solidified part (11) of the weld;
- capturing the sound waves reflected from the three different areas
(9,10,11) in the respective transducers (6,7,8) from which the ultrasound
waves (4) were initially transmitted, the reflected signals representing the
defects or discontinuities prevailing or developing in the corresponding
areas (9,10,11); characterized by comprising:
- converting the captured sound signals into electric signals and displaying
the electric signals in respective display devices (13,14,15), the display
devices (13,14,15) each having echo indicators (12,16,17);

- comparing the electric signals with the echo indicators (12,16,17) in the
display devices (13,14,15) to determine the magnitude of defects or
discontinuities; and
- adjusting the welding parameters corresponding to the detected defects
to avoid formation of further defects, wherein a positional value (W2) of
the echo-indicator (17) at the display device (15) if greater than that (WI)
of the echo-indicator (12) at the display device (13), the resultant weld is
considered to be defect-free.

2. The method as claimed in claim 1, wherein the transducers (6,7,8) are
periodically cooled during the on-line testing to avoid heating.
3. An ultrasonic testing system for carrying out the method as claimed in
claims 1 and 2, comprising:
- a plurality of transducers (6,7,8) capable of orientation and axial
movement at different directions and transmitting ultrasonic sound wave
(4), the transducers (6,7,8) being enabled to receive back the ultrasonic
sound wave (4) when reflected from an object; and

- a plurality of display devices (13,14,15) operably connected to the
respective transducers (6,7,8) for indicating the reflected-echo parameters
(12,16,17) of the ultrasonic sound signal (4) when converted from
electric signals.

ABSTRACT

TITLE: A METHOD FOR DETECTION OF DEFECTS DURING WELDING BY
ULTRASONIC TESTING
The invention relates to a method of on-line detection and control of defects
forming in an object during a welding operation, comprising the steps of
providing an ultrasonic testing system having multiple transducers (6,7,8),the
transducers (6,7,8) being movable in correspondence with the movement of a
welding torch; transmitting a first ultrasonic sound wave (4) via a first transducer
(6) directed to an unwelded area (9) of the object; transmitting a second
ultrasonic sound wave (4) via a second transducer (7) directed to a molten pool
(10); transmitting a third ultrasonic sound wave (4) via a third transducer (8) to
a just-solidified part (11) of the weld; capturing the sound waves reflected from
the three different areas (9,10,11) in the respective transducers (6,7,8) from
which the ultrasound waves (4) were initially transmitted, the reflected signals
representing the defects or discontinuities prevailing or developing in the
corresponding areas (9,10,11); characterized by comprising converting the
captured sound signals into electric signals and displaying the electric signals in
respective display devices (13,14,15), the display devices (13,14,15) each having
echo indicators (12,16,17); comparing the electric signals with the echo
indicators (12,16,17) in the display devices (13,14,15) to determine the
magnitude of defects or discontinuities; and adjusting the welding parameters
corresponding to the detected defects to avoid formation of further defects,
wherein a positional value (W2) of the echo-indicator (17) at the display device
(15) if greater than that (WI) of the echo-indicator (12) at the display device
(13), the resultant weld is considered to be defect-free.

Documents:

00373-kol-2007 correspondence-1.1.pdf

00373-kol-2007 form-18.pdf

0373-kol-2007 abstract.pdf

0373-kol-2007 assignment.pdf

0373-kol-2007 claims.pdf

0373-kol-2007 correspondence others.pdf

0373-kol-2007 description(complete).pdf

0373-kol-2007 drawings.pdf

0373-kol-2007 form-1.pdf

0373-kol-2007 form-2.pdf

0373-kol-2007 form-3.pdf

373-KOL-2007-(19-03-2012)-CORRESPONDENCE.pdf

373-KOL-2007-(24-01-2013)-ABSTRACT.pdf

373-KOL-2007-(24-01-2013)-CLAIMS.pdf

373-KOL-2007-(24-01-2013)-CORRESPONDENCE.pdf

373-KOL-2007-(24-01-2013)-PA.pdf

373-KOL-2007-ABSTRACT.pdf

373-KOL-2007-AMANDED CLAIMS.pdf

373-KOL-2007-DESCRIPTION (COMPLETE)-1.1.pdf

373-KOL-2007-DRAWINGS.pdf

373-KOL-2007-EXAMINATION REPORT REPLY RECIEVED.pdf

373-KOL-2007-FORM 1-1.1.pdf

373-KOL-2007-FORM 2-1.1.pdf

373-KOL-2007-FORM 3-1.1.pdf

373-KOL-2007-OTHERS.pdf

373-KOL-2007-PA.pdf

373KOL-2007-CANCELLED COPY.pdf

373KOL-2007-CORRESPONDENCE.pdf

373KOL-2007-EXAMINATION REPORT.pdf

373KOL-2007-FORM 18.pdf

373KOL-2007-GPA.pdf

373KOL-2007-GRANTED-ABSTRACT.pdf

373KOL-2007-GRANTED-CLAIMS.pdf

373KOL-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

373KOL-2007-GRANTED-DRAWINGS.pdf

373KOL-2007-GRANTED-FORM 1.pdf

373KOL-2007-GRANTED-FORM 2.pdf

373KOL-2007-GRANTED-FORM 3.pdf

373KOL-2007-GRANTED-SPECIFICATION-COMPLETE.pdf

373KOL-2007-REPLY TO EXAMINATION REPORT.pdf

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Patent Number

255668

Indian Patent Application Number

373/KOL/2007

PG Journal Number

11/2013

Publication Date

15-Mar-2013

Grant Date

13-Mar-2013

Date of Filing

13-Mar-2007

Name of Patentee

BHARAT HEAVY ELECTRICALS LIMITED

Applicant Address

REGIONAL OPERATIONS DIVISION(ROD), PLOT:9/1, DJ BLOCK, 3RD FLOOR, KARUNAMOYEE, SALT LAKE CITY, KOLKATA-700091, INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	SETHURAMA SRINIVASA ANANTHAN	WELDING RESEARCH INSTITUTE, BHARAT HEAVY ELECTRICALS LIMITED, TIRUCHIRAPPALLI-620 014
2	SRINIVASAN SURESH	WELDING RESEARCH INSTITUTE, BHARAT HEAVY ELECTRICALS LIMITED, TIRUCHIRAPPALLI-620 014
3	GANAPATHY UMASHANKER	WELDING RESEARCH INSTITUTE, BHARAT HEAVY ELECTRICALS LIMITED, TIRUCHIRAPPALLI-620 014
4	NAGAMUTHU DHANASEKARAN	WELDING RESEARCH INSTITUTE, BHARAT HEAVY ELECTRICALS LIMITED, TIRUCHIRAPPALLI-620 014

PCT International Classification Number

G01N3/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA