Description:“FIXTURE ASSEMBLY DEVICE FOR WELDING OF WORK PIECE WITH CARRIER PLATES AND A METHOD FOR FIXING THEREOF”

FIELD OF INVENTION:
[001] The present invention relates to manufacturing of super critical links made up pipes with load carrier plate. More particularly the invention relates to a device used for fitting load carrier plates without stiffener plates.

BACKGROUND OF THE INVENTION:
[002] 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.

[003] A pipeline is used to transport hot medium, namely water, steam, mixture of steam and water. A carrier plate is a load bearing member, which is welded over the pipes. It is used to lift the pipe to the desired areas. Moreover, carrier plate is used to clamp the piping in position at site, when it is connected with tie rods, which in turn is connected with load hangers will transfer the weight to the steel structures. However, the welding of carrier plates over the pipes is a time consuming process.

[004] Moreover, the method of carrying out the fit-up of the carrier plates on the pipe involves, marking the location of the carrier plates on the circumference of the pipe by dividing the circumference into four or eight as per requirement. Preparation of pipe surface by grinding on the pipe at carrier plate fit-up locations. Pre-heating the pipe surface before fit-up. Positioning the carrier plates manually on the marked location. Tacking the carrier plates on the pipe surface. Since the positioned & tacked carrier plate is to be retained at the position without any distortion in alignment/orientation or dimensions, there is a need to constraint them with the help of stiffener plates. Stiffener plate is a low thickness (12-16 mm) rectangular or square piece, which is of the same specification as the parent metal.

[005] The purpose of the stiffener plate is to retain the tacked carrier plate in position, without allowing for disturbance of the dimensional location and orientation/alignment. A stiffener plate once used, cannot be re-used. After arresting the carrier plate in position with the help of the stiffener plate the carrier plate is welded on one side, using SMAW process. After one side welding of the carrier plate is completed the stiffener plate is removed by hammering.

[006] This method has some inherent disadvantages as follows:
[007] It is a time consuming process, Consumption of raw material for making of stiffener plate, while removing the stiffener plates the ugly tack marks are left behind. The tack marks are to be ground flush with the pipe surface. In-case the parent metal is scooped off during the process of removing the carrier plates then build-up of the parent metal needs to be carried out in case of non-P91 material. Reworking of the pipe is cost and time consuming. In case of P91 material, build-up is not allowed making the pipe unusable.

[008] This is one of the reasons for more cycle time. Hence there is a necessity to find out an alternate method without using of stiffener plates for carrier plate fit up and welding.

OBJECTS OF THE INVENTION:
[009] An object of invention is to propose a device for pipe with carrier plate welding.

[0010] Another object of the invention is to propose a method of fixing two carrier plates inline alignment to make at a time to 180° for root and fillet welding.

[0011] A further object of the invention is to reduce the adjusting time spent on the jaws of circular type fixture.

[0012] Yet another objective of the invention is to avoid the usage of stiffener plates and to minimize the expenses incurred on practicing actual process layout.

[0013] Still another object of the invention is to eliminate the parent metal damage caused by the tacking of stiffener plates and scooping of parent metal, weld build up, flush grinding, NDT (magnetic particle inspection) and unwanted movement works.

[0014] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF INVENTION:
[0015] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method 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 part of the claimed disclosure.

[0016] According to the invention, a method of fixing pipes inline for a fit-up device has been developed together with assembly of the device along with two work pieces to be welded.

[0017] The work pieces’ rest on the roller stand. Each pipe length is about 6 meter and the outside diameter ranges from 219 to 558 mm. Multiple angle plates are made up of low alloy steel, that was fabricated so as to cover the above range of pipes.

[0018] One angle plate is inter connected by one support plate. Similarly, another angle plates are interconnected by another similar support plate. Plurality of hexagonal nuts are welded at each end of the angle plate assembly on the same side. The bottom nut acts as the lock nut and top nut acts as guiding piece. A locking screw is screwed simultaneously through guiding nut and up to the lock nut. The screw rod is made with M16 external thread, plurality of M16 hexagonal nuts are screwed at two end of the M16 screw. These M16 screw with nut assembly is taken to weld one end with the angle plate and other end with an internal threaded sleeve, to ease internal thread sleeve already assembled with hinge screw rod which is having M30 left-hand thread on one side and M30 right-hand thread on the other side. This hinge screw rod is having preferably hexagonal shape machined at the middle of the rod.

[0019] The above total assembly is being only one kg and can be easily handled. Now by opening the assembly on one end by screwing the locking screw anti-clock wise to release from the lock nut but up to the guiding nut so as to insert the device on any diameter of the pipe ranges given above. After opening the assembly, the total device is then inserted in to the pipes which are to be welded by welding process. Now the total length of the device is adjusted linearly so that equal distance is maintained from the end of the pipes to be welded. The top and bottom angle plate assembly is tightened by rotating the hinge screw rod and arresting on all directions. Now the fixture is ready for welding by the tightness of the device with the pipe, which is confirmed by simply rotating the pipe on the rollers and it ensures tight fittings and now the pipe fitting is ready for pipe to pipe welding. Thus, the drawbacks said in the conventional method of welding using the stiffener plate method are completely avoided.

[0020] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

[0021] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

[0022] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
[0023] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:

Fig-1 shows: the angle plate.
Fig-2 shows: the hinge screw rod with hexagonal nut in the middle.
Fig-3 shows: the dovetail assembly.
Fig-4 shows: the support plate.
Fig-5 shows: the elevation for the semi-assembly.
Fig-6 shows: the elevation for the assembly of the device along with two work pieces which are to be welded.

[0024] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily 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 A PREFERRED EMBODIMENT OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:
[0025] 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.

[0026] In the present power scenario of India, boiler production, erection and commissioning plays a major role in country’s growth. Links (Piping) are the first pressure part components that have to be erected for a High Pressure High Temperature Steam Generator. In Steam generator, at the middle of pipes, four Carrier plates are welded to the pipes and headers. The carrier plates are used in Boiler piping for lifting and clamping purpose. On an average each steam generator requires welding of approximately 100-150 P91, carbon and alloy carrier plates. The welding of carrier plates over the pipes is a time consuming process. Moreover, stiffener plate has been used as an aiding medium for ensuring the proper alignment of carrier plate over pipe during fit-up. Once the welding process is accomplished the stiffener plate is subjected to removal. The removal of stiffener plate ends up with causing damage to the parent material which requires grinding operation on the pipe surface. Therefore, the invention is keenly concerned on eliminating the presence of the stiffener plate. For that, solution has been come in the form of fixtures.
[0027] Thus, fixture holds the carrier plate firmly without the aid of stiffener plates. The present invention involves elimination of stiffener plates welding on carrier plates fit-up for the super critical links by using suitable fixture. The use of new fixture eliminates various process like using of stiffener plates, scooping of parent metal, weld build up and flush grinding, NDT (magnetic particle inspection) and movement works.

[0028] The present invention makes a disclosure regarding a technology pertaining to invention directing to Fixture assembly device for welding of work piece with carrier plates and a method for fixing thereof.

[0029] Figure 1 shows: An Alloy plate of material Gr 22 is obtained out of which a V block has been cut out of the required dimension.

[0030] Figure 2 shows: A Hinge Screw rod fabricated using a Rod. Chromium alloy material is used for the fabrication of this screw Rod without restricting scope of the invention to the same. The rod is further machined with left and right hand threads for ease in expansion and contraction.

[0031] Figure 3 shows: Dovetail fit comprising of a base plate in which the dovetail assembly is held on its top. Dove tail arrangement with sliding mechanism are attached to the base plate using a level screw, in which the sliding motion of the sliding plate is arrested by drilling a hole in the center of the plate and placing a screw in the hole.
[0032] It has four clamping jaws mounted on a dove tail mechanism for sliding arrangement, which serves the dual purpose of locating/positioning of the carrier plates and clamping them on the pipe.

[0033] Figure 4 shows: Support plate (6) seated under the dovetail assembly (Fig-3).

[0034] Figure 5 shows: Various components that have been fabricated are assembled by attaching the hinge to the angle plate and screwing the Screw to the other part of the hinge and then the foldable wrench type lock is assembled to the other side of the angle plate which helps in locking the fixture firmly with the pipe thereby arresting its motion. The overall finished product resembles almost like as shown.

[0035] Figure 6 shows: Working model by using the newly developed fixture, wherein the presence of stiffener plate is totally avoided. This helps in reducing the material cost of stiffener plate, welding and removal time. Further, the damage to the main pipeline is totally eliminated.

[0036] Now, reference may be made to Figure 6 illustrating different parts of the device with work piece (01) and carrier plate/lug plate (02). The angle plate (03) is having inclined opening for easy positioning the work piece (01) and the angle taper is made ⁓45 degrees to the horizontal. The angle plate (03) is welded with horizontal support plate (06) for perfect seating of the work pieces/carrier plate (01&02) as it is clamped with semi-circle angle plates (03) and tightened with adjustable hinge screws (08). Another portion of the angle plates (3) is locked on the locking screw (04). The two angle plate clamps are also tightened with adjustable hinge screws (08).

[0037] The maximum outside diameter of the work piece is 558mm and thickness of the pipe is 45mm and these pipes are used as steam generator package links.

[0039] The horizontal pipe (01), (02) are welded with the pipe for fixing the angular plates (03) and (05) so as to use the adjustable hinge screws (08) effectively.

ADVANTAGEOUS FEATURES:
[0039] The present invention is used for making quality welding joints without stiffener plates and thereby drastically reducing in cycle time from 8 hours to 3 hours per joint and thereby substantial savings in power, money and material.

[0040] This method has more tangible and intangible saving i.e. more financial benefits per annum.

WORKING OF INVENTION:
[0041] According to the present invention, the root welding is carried out by positioning the work pieces in the device with suitable angle pates and adjustable hinge screws at a places. One is in the vertical direction used for locking purpose only and two angle plate clamps are in the horizontal direction. The whole assembly is attached to the stud with threaded sleeve (shown in Fig 6) and now the assembly of roller stand pipe with load carrier/lug plate is carried out with easy handling of the fixture without much effort.

[0042] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0043] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0044] 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 particulars 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 analogues 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”.

[0045] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[0046] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0047] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0048] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
, Claims:WE CLAIM:

1. Fixture assembly device for welding of work piece with carrier plates comprises of:
a work piece (01) with a carrier plate/lug plate (02) at top and bottom part thereof, wherein the work pieces (01&02) are clamped with semi-circle angle plates (03) and the angle plate clamps (03) are tightened with adjustable hinge screws (08), in which another portion of the angle plates (3) is locked on a locking screw (04), and the angle plate (03) is connected with horizontal support plate (06) for seating of the work pieces (01&02).

2. The Fixture assembly device as claimed in claim 1, wherein the angle plate (03) is having inclined opening for easy positioning the work piece (01) and the angle taper is made 55 degrees to the horizontal.

3. The Fixture assembly device as claimed in claim 1, wherein the maximum outside diameter of the work piece is 558mm and thickness of the pipe is 45mm and these pipes are used as steam generator package links.

4. The Fixture assembly device as claimed in claim 1, wherein the angle plate (03) is welded with horizontal support plate (06) for perfect seating of the work pieces (01&02).

5. The Fixture assembly device as claimed in claim 1, wherein the horizontal pipe (01), (02) are welded with the pipe for fixing the angular plates (03) and (05) so as to use the adjustable hinge screws (08) effectively.

6. The Fixture assembly device as claimed in claim 1, wherein dovetail fit (5) is held by the support plate (06), in which the dovetail fit (5) comprising of a base plate in which the dovetail assembly is held on its top, in which these plates are attached to the base plate using a level screw, in which the sliding motion of the center plate is arrested by drilling a hole in the center of the plate and placing a screw in the hole.

7. A method of fixing fixture assembly device for welding of work piece with carrier plates comprising the steps of:
placing a pipe in the horizontal pipe (01,02) which is having 55-degree slant;
opening to position the job/pipe with angle plate (03) connected on the top and bottom of the horizontal pipe/work pieces (01,02), in which the position is adjusted by adjustment screws (4) on the both sides;
positioning the work piece in the horizontal directions by adjustable hinge screws (08) and semi angular plate (03);
fixing of the work piece on the horizontal pipe (01,02) and angle plates (03) with support plate (06), in which the dovetail fit (05) is fitted on each side of the work piece.

8. The method as claimed in claim 7, wherein the angle plates (03) (05) are varied according to the outside diameter of the pipe (01) (02) and tightening of the hinge screw rod (08) to hold cylindrical objects due to its self-center for vertical position.