FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)

TITLE OF THE INVENTION

“WELDING OF PIPES PERPENDICULALY TO ONE ANOTHER”

APPLICANTS:

Name Nationality Address
BHARAT HEAVY ELECTRICALS LIMITED Indian BHEL HOUSE, SIRI FORT, NEW DELHI – 110049, INDIA., with one of its manufacturing units at
High Pressure Boiler Plant, Tiruchirapalli - 620014, Tamil Nadu

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:-
TECHNICAL FIELD

[001] Embodiments generally relate to the field of welding, and more specifically embodiments relate to the field of welding pipes substantially perpendicularly to each other.
BACKGROUND
[002] Two pipes are welded substantially perpendicular to each other when one end of a pipe (hereinafter referred to as tail pipe) is welded perpendicularly to a second pipe (hereinafter referred to as head pipe) when the head pipe and tail pipe are configured perpendicularly to each other. Such welding is generally carried out using a process called Shielded Manual Arc Welding (SMAW) process.
[003] In SMAW process the head pipe is drilled such that diameter of the drill is equal to the internal diameter of the tail pipe. Further, edge of the drilled hole in the head pipe and the edge of one end which will be welded to the head pipe are prepared as per existing standards. Subsequently, after drilling and preparation of edges, the tail pipe and the head pipe are positioned perpendicularly to one another. In SMAW process electrode that is coated with flux is used for welding. During the welding process the electrode melts and the flux coating is disintegrated, thereby producing vapour that protects the area that is welded from atmospheric gases. Additionally, the flux provides molten slag which protects the weld from contamination as it solidifies. After the slag is hardened, the slag is chipped away to reveal the finished weld.
[004] In the SMAW process as the welding progresses, the electrode melts, thereby, reducing the length of the electrode. After the length is reduced to a certain extent, the welder discards the remaining electrode and mounts a new electrode stick into the electrode holder. Further, the length of the electrode that is discarded varies based on the welder. In the SMAW process substantial amount of electrode is wasted as the same is discarded, thereby making the process expensive. Further, the discarded electrodes contribute to environmental pollution. In the SMAW process the welder spends substantial amount of time in removing the electrode to discard the same and mounting a new electrode in the electrode holder. Hence, a substantial amount of time is wasted in removing and mounting the electrode, thereby making the SMAW process inefficient.
[005] In SMAW process, the weld quality depends on the skill of the welder. Hence, in order to ensure weld of high quality, highly skilled welders are required. Further, the SMAW process is highly labour intensive. SMAW process being highly labour intensive and since highly skilled labour are required, leads to increase in the cost of welding. Further, the SMAW process being labour intensive is also time consuming.
[006] Additionally, in the SMAW process under cut and lack of fusion are revealed only after completion of welding. Therefore, in cases where under cuts and lack of fusion exit, the time and money spent in welding are wasted.
OBJECT OF INVENTION
[007] An object is to provide a method for welding together a head pipe and a tail pipe substantially perpendicular to each other.
[008] Another object is to provide a system for welding together a head pipe and a tail pipe substantially perpendicular to each other
STATEMENT OF INVENTION
[009] An embodiment herein provides a method for welding together a head pipe and a tail pipe substantially perpendicular to each other. The method includes preparing edge of the tail pipe and edge of the head pipe for welding. Further, configuring the tail pipe and the head pipe substantially perpendicular to each other, wherein the prepared edge of the tail pipe and the prepared edge of the head pipe interface with each other, thereby defining a profile. The configured head pipe and the tail pipe are rotated simultaneously. While the head pipe and the tail pipe are rotated, the profile defined by the edge of the tail pipe and the edge of the head pipe are welded.
[0010] An embodiment herein provides a system for welding together a head pipe and a tail pipe substantially perpendicular to each other. The system includes an electrode feeding mechanism. The electrode feeding mechanism comprises an electrode feed motor, wheels, a feeding unit and an adjustment mechanism. The electrode feed motor feeds electrode that will be used for welding the head pipe and the tail pipe which are configured perpendicularly to each other. The electrode fed by the electrode feed motor is moved by the wheels which rotate. The electrode moved by the wheels is received by the feeding unit and provides the electrode for welding the head pipe and the tail pipe. The adjustment mechanism is configured to move the feeding mechanism to enable movement of feeding unit in accordance with a profile defined by a prepared edge of the head pipe and a prepared edge of the tail pipe, thereby enabling the welding of head pipe and tail pipe perpendicularly to each other.
[0011] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF FIGURES
[0012] This invention is illustrated in the accompanying drawings, through out which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0013] FIG. 1a illustrates two pipes welded in T configuration, in accordance with an embodiment;
[0014] FIG. 1b illustrates two pipes welded in T configuration, in accordance with an embodiment;
[0015] FIG. 1c illustrates pipes welded in T configuration, in accordance with an embodiment;
[0016] FIG. 2 illustrates head pipe and tail pipe whose edges are prepared, in accordance with an embodiment;
[0017] FIG. 3 illustrates head pipe and tail pipe being configured in a T configuration, in accordance with an embodiment;
[0018] FIG. 4 illustrates an assembly mounted onto a positioner assembly, in accordance with an embodiment;
[0019] FIG. 5 illustrates a system for welding the head pipe and the tail pipe while the assembly formed by the head pipe and the tail pipe is rotated, in accordance with an embodiment; and
[0020] FIG. 6 illustrates an adjustment mechanism which enables movement of feeding mechanism, in accordance with an embodiment.
DETAILED DESCRIPTION
[0021] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0022] The embodiments herein disclose welding pipes in T configuration. Referring now to the drawings, and more particularly to FIGS. 1 through 6, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0023] Embodiments enable welding of two pipes in a configuration in which the pipes are substantially perpendicular to each other. The configuration in which the pipes a welded substantially perpendicular to each other is referred to as T configuration. Further, the portion at which the two pipes interface and are welded to form a joint thereby forming the T configuration is referred to as T joint. FIG. 1a illustrates two pipes welded in T configuration 100, in accordance with an embodiment. In FIG. 1a T configuration is formed by welding head pipe 102 and tail pipe 104 together. It may be noted that a T configuration may refer to two or more pipes configured in ways other than the one illustrated in FIG. 1a. Another configuration of two pipes welded together to form a T configuration is illustrated in FIG. 1b. In FIG. 1b one end of head pipe 102 and one end of tail pipe 104 are welded together to form T configuration. In another embodiment, as illustrated in FIG. 1c tail pipe 104 and second tail pipe 106 are welded to head pipe 102 to form T configuration. It light of the foregoing, it will be clear to a person skilled in the art that more than one tail pipe can be welded to a head pipe to form T configuration.
[0024] In an embodiment, to form T configuration 100, edges of the head pipe 102 and tail pipe 104 are prepared, wherein the prepared edge of head pipe 102 interfaces with prepared edge of tail pipe 104. FIG. 2 illustrates head pipe 102 and tail pipe 104 whose edges are prepared, in accordance with an embodiment. To prepare edge in head pipe 102, a hole is drilled through the surface of the head pipe 102. In an embodiment, the diameter of the drilled hole is substantially equal to the internal diameter of the tail pipe 104, wherein the tail pipe 104 is a hollow pipe. Subsequent to drilling, the edge formed as a result of drilling is prepared as per established standards. Further, one end of the tail pipe 104 which interfaces with the head pipe 102 is prepared as per established standards to define an edge.
[0025] The head pipe 102 and the tail pipe 104 whose edges are prepared for welding are mounted on fixtures in such a way that the head pipe 102 and tail pipe 104 define a T configuration. FIG. 3 illustrates head pipe 102 and tail pipe 104 being configured in a T configuration, in accordance with an embodiment. In FIG. 3 head pipe 102 is mounted on a block 300 whose surface defines a V shaped curvature in which the head pipe 102 is accommodated. The head pipe 102 which is mounted on V block 300 is parallel to the ground, whereas the tail pipe 104 is held by a fixture (not shown) perpendicularly to head pipe 102 while maintaining a gap with the head pipe 102. In an embodiment, the gap which may be referred to as root gap is in the range of 3mm to 4mm. In an embodiment, tack welding is carried out on head pipe 102 and tail pipe 104 to ensure perpendicularity is maintained between head pipe 102 and tail pipe 104, the tack welding is facilitated by tack welding supports 302. In an embodiment, tack welding is carried out using Tungsten Inert Gas (TIG) welding process. The head pipe 102 and the tail pipe 104 which are now configured in T configuration under goes root welding at the root gap between head pipe 102 and tail pipe 104, thereby forming an assembly in which head pipe 102 is attached to tail pipe 104 in T configuration.
[0026] The assembly in which the head pipe 102 is attached to tail pipe 104 in T configuration is made to rotate while the T joint is further welded. In an embodiment, rotation of the assembly is enabled by mounting the assembly onto a positioner assembly. FIG. 4 illustrates the assembly mounted onto a positioner assembly 402, in accordance with an embodiment. The positioner assembly 402 comprises four screws which are equally spaced. The four screws can be simultaneously tightened or loosened. Tightening of the screws enables engagement of tail pipe 104 with the positioner assembly 402. The positioner assembly engages with tail pipe 104 at the free end of the tail pipe 402. Further, the positioner assembly is capable of rotating the tail pipe 102 using a motor (not shown) along the longitudinal axis 404 of the tail pipe 104. Since, the head pipe 102 is connected to the tail pipe 104 as a result of root welding, the head pipe 102 also rotates when the tail pipe is rotated. In an embodiment, the tail pipe 104 is further supported by a roller assembly 406, which further facilitates rotation of the tail pipe 104 along with providing support to the tail pipe 104. As the assembly is rotated, the head pipe 102 and the tail pipe 104 are welded together along a profile defined by the prepared edges of the head pipe and the tail pipe.
[0027] FIG. 5 illustrates a system 500 for welding the head pipe 102 and the tail pipe 104 while the assembly formed by the head pipe 102 and the tail pipe 104 is rotated, in accordance with an embodiment. System 500 comprises an electrode feeding mechanism 502 comprising an electrode feed motor 504, electrode 506, rotating wheel 508 and feeding unit 510. The electrode feeding mechanism 502 feeds electrode 506 that will be used for welding the profile defined by the head pipe 102 and tail pipe 104. The electrode feed motor 504 supplies electrode 506 that is wound on a spool (not shown) to the rotating wheels 508. The electrode 506 which is passed between the rotating wheels 508 is supplied to the feeding unit 510 as a result of rotation of adjacent rotating wheels 508 in opposite directions while the electrode is in contact with the surface of the rotating wheels 508. The electrode 506 received by the feeding unit 510 is used to weld the profile defined by the head pipe 102 and the tail pipe 104 together. The welding is carried out when the assembly is rotated along the axis 404. In an embodiment, the electrode feeding mechanism 502 is moved thereby enabling feeding unit 510 to move in accordance with the profile defined by the head pipe 102 and tile pipe 104.
[0028] FIG. 6 illustrates an adjustment mechanism 600 which enables movement of feeding mechanism 502, in accordance with an embodiment. The adjustment mechanism 600 comprises of first screw 602 and a second screw 604. Further, the feed mechanism is engaged with the second screw 604 using a coupling assembly 606. The first screw 602 is configured to be rotated to enable movement of the first screw along first axis 608, and the second screw 602 is configured to be rotated to enable movement of the second screw along second axis 610. Additionally, the first screw 602 and the second screw 604 are configured in such a way that movement of the first screw 602 along the first axis 608 enables the movement of screw 604 along the same first axis 608. Further, the feeding mechanism 502 is coupled with the second screw 604 in such a way that, rotation of the second screw 604 enables corresponding movement of the adjustment mechanism along the second axis 610. Hence, the feed mechanism 502 can be moved based on the profile that needs to be welded by adjusting (rotating) the first screw 602 and second screw 604.
[0029] In some embodiments, some actions listed provided above may be omitted or may be carried out in an order other than the order mentioned above.
[0030] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

WE CLAIM:

1. A method for welding together a head pipe and a tail pipe substantially perpendicular to each other, the method comprising:
preparing edge in the tail pipe for welding;
preparing edge in the head pipe for welding;
configuring the tail pipe and the head pipe substantially perpendicular to each other, wherein the prepared edge of the tail pipe and the prepared edge of the head pipe interface with each other, thereby defining a profile;
rotating simultaneously the head pipe and the tail pipe which are configured perpendicularly to each other; and
welding the profile defined by the edge of the tail pipe and the edge of the head pipe while the tail pipe and the head pipe are simultaneously rotated.

2. The method according to claim 1, wherein, preparing edge in the head pipe comprises, drilling surface of the head pipe to define a hole having diameter substantially equal to internal diameter of the tail pipe.
3. The method according to claim 1, wherein, configuring the prepared edge of the tail pipe with the prepared edge of the head pipe comprises, tack welding the head pipe and tail pipe.
4. The method according to claim 3, wherein the tack welding is performed using tungsten inert gas welding process.
5. The method according to claim 1, wherein, configuring the prepared edge of the tail pipe with the prepared edge of the head pipe comprises, maintaining a gap between the prepared edge of the head pipe and the prepared edge of the tail pipe.
6. The method according to claim 1, further comprises, root welding the gap between the prepared edge of the head pipe and the prepared edge of the tail pipe.
7. The method according to claim 1, wherein, welding the profile comprises, moving a feeding unit in accordance with the profile.
8. The method according to claim 7, wherein moving a feeding unit is enabled by rotating one or more of a first screw and a second screw.
9. A system for welding together a head pipe and a tail pipe substantially perpendicular to each other, the system comprising a electrode feeding mechanism comprising:
an electrode feed motor for feeding electrode that will be used for welding the head pipe and the tail pipe which are configured perpendicularly to each other;
wheels interfacing the electrode fed by the electrode feed motor and moving the electrode while the wheels rotate;
a feeding unit receiving the electrode form the wheels and providing the electrode for welding the head pipe and the tail pipe; and
an adjustment mechanism configured to move the feeding mechanism to enable movement of feeding unit in accordance with a profile defined by a prepared edge of the head pipe and a prepared edge of the tail pipe.

10. The system according to claim 9, wherein the adjustment mechanism comprises a first screw and a second screw, wherein the first screw and the second screw are configured to move the electrode feeding mechanism along a first axis and a second axis.
11. The system according to claim 10, wherein the electrode feeding mechanism is engaged with the second screw using a coupling assembly.
12. The system according to claim 10, wherein each of the first screw and the second screw are configured to being rotated independently to move the electrode feeding mechanism.
13. The system according to 9, wherein an assembly formed by the head pipe and the tail is mounted onto a positioner assembly.
14. The system according to claim 13, wherein the tail pipe is engaged with the positioner assembly.
15. The system according to claim 13, wherein the positioner assembly is configured to rotate the tail pipe.
16. The system according to claim 9, wherein the tail pipe is supported by a roller assembly.
17. A method for welding together a head pipe and a tail pipe substantially perpendicular to each other substantially as herein above described in the specification with reference to the accompanying drawings.
18. A system for welding together a head pipe and a tail pipe substantially perpendicular to each other substantially as herein above described in the specification with reference to the accompanying drawings.

Dated this 4th June 2009

Mr. Nishant Kewalramani
Patent Agent for Applicant