Claims:A rear feed stand for more than 12m. length tube loading in STBW machine. The steel tube (1) which are to be welded with another steel tubes having proper edge preparation (12) are loaded in the rear feed stand (13) by using a crane (not shown) and the tube are spread with back to back position on the slope beam (3) and sliding rod (4). A slope of 15 degrees to the horizontal plane provided on the slope beam (3) for auto tube (1) rotation. The sliding rod (4) welded in between the slope beam (3). The adjustable tube stopper (5) ensures alignment of the tube (1) to placing the tubes (1) on the support roller (7) by the tapper plate (14) link with the pneumatic cylinder lifting one tube (1) and by gravity the tube (1) fall exactly on the support roller (7) and in between pinch roller (8). , Description:FIELD OF INVENTION
The present subject matter generally relates to manufacturing of economiser coils for steam generator. Particularly, present subject matter relates to joining of tubes having more than 12 meter in length. More particularly, present subject matter relates to avoid cut-bit generation, cut-bit storage and extra addition joints in straight tube butt welding (STBW) machine. Still the present subject matter relates to reduction cycle time by modified device used in STB welding machine.
BACKGROUND OF THE INVENTION
[001] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[002] During fabrication of coils for high pressure and high temperature steam generator. There are several stages starting from tube receiving to tube sizing to STBW welding to real time radiography test to tube bending to coil fit-up to painting and shipping. Gas Metal Arc Welding(GMAW) is a welding process being carried out in our area to join the tubes of standard length to a build-up length of up to 42 m. This process is carried out in Straight tube butt welding (STBW) machines. The standard length tubes were procured in length of 10 m, 11 m and 12 m only. It was because the supplier capacity to produce seamless tubes were limited to a maximum length of 12.15 m. With modernization and new technological advancements, the suppliers increased their capacity to supply seamless tubes of up to 14 m of length. But, the capacity of straight tube welding machines available in our area were designed to accommodate tubes of length up to 12 m only.
[003] Hence, the tubes received in 14 m of length were required to be cut in 12 m so that they can be loaded in the STBW machines. Due to this reason, lots of cut bits were generated and if the cut bits were to be utilized, additional joints have to be planned in the project. This increased the work content and cycle time of the project.
[004] Despite increasing the raw material length, the full length of 14 m tubes was underutilized. Increasing number of joints for the utilization of cut bits generated further increased the cycle time of the project. The cost of renovation of STBW machines to accommodate 14 m tubes was around Rs. 15,00,000 which was very high. These facts gave drive to the idea of designing a new device that can feed 14 m of tubes to the STBW machines.
[005] There is a need for a rear feed mechanism that can extended to any length of the tube to feed the tube from the rear side of the STB welding machine.
[006] The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
OBJECT OF THE INVENTION
[007] It is therefore the object of the invention to overcome the aforementioned and other drawbacks in prior method and valves.
[008] Another object of the invention is to propose a device for rear feeding of tubes having more than 12m length in STBW machine.
[009] Another object of the invention is to improve the existing machine to suit to weld more than 12-meter length.
[010] Yet another object of the invention is to propose a device which will be added in the existing STB welding machine to weld any length more than 12 meter.
[011] Yet another object of the invention is to reduce the cycle time, Increase the productivity by avoiding 2 meter cut-bit waste of using 14-meter length tube in STB welding machine.
[012] These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taken into consideration with accompanying drawings in which preferred embodiments of the present subject matter are illustrated.

SUMMARY OF THE INVENTION
[013] One or more drawbacks of conventional STBW machine for welding, and additional advantages are provided through the device as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure.
[014] Normally the maximum length of seamless steel tubes available only 12 meter. Due to technology advancement 12-meter length of tube received for welding in STB welding machine. In order to utilize the full length of tube a device is added as mention below. Accordingly, the 14-meter length of tube are loaded in the Slope beam before the safety pillar. The tubes are moved along the sliding rod and reached the adjustable stopper. The pneumatic cylinder is actuated so that the tapper plate lifting the tube in between the pinch roller. So that the tube which to be welded is moved to the straight tube butt welding machine from right side. This mechanism is known as rear feed mechanism to utilize the to feed tubes in having more than 14 meter in length.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[015] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[016] Figure 1 shows the schematic layout of existing tube feeding mechanism used in the existing STB welding machine to weld 12-meter length tube to tube welding;
[017] Figure 2 shows the improved device added in the existing STB welding machine for rear feed mechanism to feed more than 14-meter length of tube for welding;
[018] Figure 3 shows the schematic layout of existing method incorporated a device of rear feed stand with item no.13.
[019] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
[020] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
[021] The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device, system, assembly that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.
[022] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[023] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[024] The present subject matter discloses a device for rear feeding of tubes (1) in STBW machine, the device comprises a plurality of support structures (A and B) having plurality of vertical columns (11), vertically fixed on a rigid surface, a slope beam (3) having one end fixed on the upper end of each vertical columns (11) of the support structure A, wherein tubes (1) are placed on the slope beam (3), an adjustable tube stopper (5) provided on the free end of each slope beam (3), a plurality of support roller (7) provided at support structure B to feed tubes in the device to STBW machine, a pneumatic cylinder (6) provided near the adjustable tube stopper (5) and a taper plate (14) provided on top of the pneumatic cylinder, wherein when pneumatic cylinder is actuated the taper plate (14) lift the tube (1) from the slope beam (3) and transfer the tube (1) to the plurality of support rollers (7) and between a pinch roller (8).
[025] Referring to the figure 2, accordingly, the steel tubes (1) which are to be welded with another steel tubes having proper edge preparation (12) are loaded in the rear feed stand (13) by using a crane (not shown) and the tubes are aligned in position on the slope beam (3). A slope of 15 degrees to the horizontal plane provided on the slope beam (3) for auto tube (1) rotation. The sliding rod (4) welded in between the slope beam (3) to have point contact instead of surface contact and ensuring gravitational flow of tubes (1). The adjustable tube stopper (5) ensures alignment of the tube (1). When the pneumatic cylinder (6) is actuated, the taper plate (14) provided in the top of the pneumatic cylinder (6) lifting one tube (1) from the slope beam (3) and transferring to the support roller (7) and ensures the tube (1) is also in between the pinch rollers (8) at the right end. Since the pinch rollers (8) are having driving mechanism, the tube (1) is taken to STB welding machine to carry out the welding. The support roller (7) is supported by vertical column (11) which rests on the ground. The safety pillar (2) welded on the slope beam (3) top preventing the tubes (1) to fall on the other side. Thus the operation is repeated as explained above to feed another tube by the actuation of the pneumatic cylinder (6).
[026] A plurality of kick off plates (9) are provided on the support structure (B) to transfer the finished/ welded product to move other side for radiography testing.
[027] The above rear feed mechanism can be extended to any length of the tube (1) to feed the tube from the rear side of the STB welding machine as explained above, Thus the draw backs are eliminated said in the back ground.
[028] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[029] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.
[030] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

We Claim:
1. A device for rear feeding of tubes (1) in STBW machine, the device comprises:
a plurality of support structures (A and B) having plurality of vertical columns (11), vertically fixed on a rigid surface;
a slope beam (3) having one end fixed on the upper end of each vertical columns (11) of the support structure A, wherein tubes (1) are placed on the slope beam (3);
an adjustable tube stopper (5) provided on the free end of each slope beam (3);
a plurality of support roller (7) provided at support structure B to feed tubes in the device to STBW machine;
a pneumatic cylinder (6) provided near the adjustable tube stopper (5); and
a taper plate (14) provided on top of the pneumatic cylinder, wherein when pneumatic cylinder is actuated the taper plate (14) lift the tube (1) from the slope beam (3) and transfer the tube (1) to the plurality of support rollers (7) and between a pinch roller (8).
2. The device as claimed in claim 1, wherein slope of slope beam (3) is between 10o to 20o in horizontal direction.
3. The device as claimed in claim 1, wherein a sliding rod (4) is provided between each slope beam (3) to have only point contact with tube (1) ensuring gravitational flow of tubes.
4. The device as claimed in claim 1, wherein the pinch roller (8) has a drive mechanism to feed the tube (1) between the pinch roller (8) into the STBW machine for welding.
5. The device as claimed in claim 1, wherein a safety pillar (2) is provided at the fixed end of each slope beam to prevent the tubes (1) to fall on the other side.
6. The device as claimed in claim 1, wherein a plurality of kick off plates (9) are provided on the support structure (B) to transfer the finished/welded product to move other side for radiography testing