FIELD OF THE INVENTION
The present invention relates to an apparatus used for submerged arc welding (SAW) of short length pipes and more particularly relates to a method to hold and weld pipes with required length in a submerged arc welding (SAW) machine.
BACKGROUND OF THE INVENTION
Boiler is a steam generator which is used to generate steam by applying heat energy to water. A typical 600 MW boiler weighs around 14000 tons in which pressure parts weight is 6000 Tons. The product lines & links (pressure parts) contribute to 1850 tons in a boiler. The working temperature & pressure of the product lines & links is 566.8 degree centigrade (max.) & 281.2 kg/sq.cm (max.). Lines & Links form the circulation system of a boiler. These are provided to connect different assemblies in a boiler and carry fuel/water/steam/vapour /mixture of all the above across all systems. Moreover, the process of butt welding the pipes of length less than 1600 mm in SAW encounters has been faced many difficulties.
The Submerged Arc Welding machine is used for butt joint welding of pipe & fittings. The length between the center of steady rest and the rotary head in Submerged Arc Welding (SAW) machine is 1600 mm. Hence the minimum length of the pipe required to undertake welding in Submerged Arc Welding (SAW) machine is 1600 mm, that is the main limitation of it. Hence the job should be at least 1600 mm length for better holding of job and welding by SAW. If the job length is less than 1600 mm, then a spool pipe of same diameter is added with the short length job. Because of this, addition of spool pipe is required. Existing procedure requires an additional pipe with more length than the job (short length pipe) and of same diameter is welded with the short length pipe with heavy bridge pieces. The spool pipe is fitted up with short length job. The fit-up is heavily welded with specially cut bridge pieces of

size 300x50x16 mm. Then the pipe is loaded for welding at SAW welding. After butt joint welding in SAW Machine, the heavy bridge pieces are removed by hammering & grinding. During the welding process cavities, where these were formed at places, were ground, pre-heated and filled by welding. After welding the area is cleaned, ground and subjected to Liquid Penetration Inspection (LPI). This entire process is repeated in sequence for both the short length pipe and the spool pipe. The reworks involved in fit-up of spool pipe with short length pipe are welding of bridge piece, removal of bridge piece through hammering and LPI on the tack weld area.
In a single job, there are one or two short length pipes. Hence in a single product group around 8 to 10 short length pipe butt joints are there on an average. The butt joint welding of Lines & Links has three phases. The root welding is carried out by Gas Tungsten Arc Welding (GTAW). Then subsequently 2 to 3 layers of Shielded Metal Arc Welding (SMAW) is done to avoid burn through and to give enough strength for loading into Submerged Arc Welding(SAW) machine where the butt joint is completed.
The difficulties encountered by welding of spool piece are:
> Addition of spool pipe by welding with the short length pipe with bridge pieces.
> Removal of Bridge pieces by oxy acetylene gas cutting or carbon rod gouging.
> Grinding, pre heating, filling of metal by welding and LPI at places where bridge pieces were removed in both in Short length pipe and in spool pipe.
> More LPG consumption.
> Due to exposure to high temperature, rework and incessant welding, there is more exhaustion for human to work.
> Surface finish of the final welding layer is not uniform for Ultrasonic Testing (UT) which requires laborious grinding.
> Requires more time to complete the welding.

The major shortcoming of this process is the addition of spool piece for short length pipe for holding in Submerged Arc Welding (SAW) Machine and removal of spool pipe after welding. In addition it also involves filling of metals through welding, LPI etc. on both the Job and spool pipe.
Hence, there is a need of an apparatus and method for welding of short length pipes directly in submerged arc welding (SAW) machine without in addition of spool piece.
OBJECTS OF THE INVENTION
It is therefore, the object of the invention to overcome the aforementioned and other drawbacks existing in prior arts.
The primary object of the present invention is to propose an apparatus to provide for welding of short length pipes directly in submerged arc welding (SAW) Machine without in addition of spool piece.
Another object of the present invention is to propose an apparatus to hold and accommodate different length of short pipes to certain range i.e. the apparatus could have a provision for minor height adjustment to obtain parallelism.
Still another object of the present invention is to provide the facility to mount the apparatus directly on the base of the submerged arc welding machine.
SUMMARY OF THE INVENTION
One or more drawbacks of conventional arts for welding the short length pipes by using Butt joints by using submerged arc welding (SAW) process, are overcome, and additional advantages are provided through the present invention as disclosed. Additional feature 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.
The present invention discloses an apparatus for welding short length pipe in a submerged arc welding (SAW) machine, comprising a pipe supporting rollers that are fixed to a top support channel by roller mounting bolt and nut. The top support channel configured to attach to a vertical column and pipe support by a mounting bolt and a height adjustment screw. A Structure consisting of vertical column and pipe support along with two horizontal support pipes adjusted along guide rods for required length and fastening. An angle adjustment screw and socket module with additional support provides minor angular adjustments and fixed on a chassis. A front levelling screws and a back levelling screws are used for levelling, wherein the back levelling screws is positioned on a base of the submerged arc welding (SAW) machine and a length of back levelling screws are lesser than the front levelling screws and a fixture configured to attach the apparatus to the SAW machine fastening means for welding the work piece.
In one embodiment the submerged arc welding method for a short length pipe, comprising the steps of providing a work piece is disclosed. Providing the two pipe supporting rollers which is fixed on a plurality of pitch holes on a top support channel. Positioning a screw and socket arrangement to align minor angular adjustment through an angle adjustment screw to obtain parallelism for the work piece. Sliding a bushes enables a top structure to slide on a guide rods to adjust for the length of the work piece. Providing a length adjustment holes on the chassis to adjust the position of the structure to accommodate and provide stable support for different length of the work piece and levelling the workpiece using a front levelling screws and a back levelling screws.
In one embodiment the submerged arc welding method wherein the short length pipe are in the range of 300 mm to 1600mm. In a preferred embodiment the submerged arc welding (SAW) machine fastening means is a mounting bolt.

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.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
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 shrouds that are consistent with the subject matter as claimed herein, wherein:
FIG.1 – illustrates an isometric view of apparatus to carry out the welding of short length pipes directly in SAW machine in an embodiment of the present invention.
FIG. 2A – illustrates an elevation of the isometric view with working piece in position.
FIG. 2B – illustrates an elevation of a sectional view along A-A of Fig 2A.
FIG. 3 – illustrates a left side view and an elevation view of a Work Piece (Short length Pipe) which has to be welded and placed in supporting rollers in position and its sectional view along B-B in an embodiment of the present invention.
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 illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE INVENTION
While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown 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.
The figures illustrate only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be clear to those of ordinary skill in the art having benefit of the description herein.
FIG.1 illustrates an isometric view of apparatus to carry out the welding of short length pipes directly in SAW machine in an embodiment of the present invention. To facilitate the holding of a short length pipe in a two pipe supporting rollers (01) which are provided at the top. The two pipe supporting rollers (01) are mounted with the help of roller mounting bolt and nuts (02). The two pipe supporting rollers (01) could be fixed on any of the pitch holes (04) provided on a top support channel (03) to accommodate different sizes of short length pipes. The top support channel (03) is mounted on a top support channel (05). Height of the top support channel (03) could be adjusted using a height adjusting lock screw & nuts (06). The top support channel (03) is supported by a vertical columns and pipe supports (07). The vertical columns and pipe support (07) structure additional strength is provided by two horizontal support pipes (08). An additional support (09) tube is connected to the two horizontal support pipe (08) through a screw and socket arrangement. The screw and socket arrangement enables to provide minor angular adjustment through angle adjustment screw (10) to obtain precise parallelism for the work piece (22). The additional support (09) tube is mounted on a chassis (16) by mounting bolt for additional support (11). A structure consisting

of vertical column and pipe supports (07) is mounted on a bottom support channel by mounting bolt for bottom support channel (13).
In one embodiment the bottom support channel (13) is mounted on a sliding bushes (14). The sliding bushes (14) enables the top structure to slide on the guide rods (15) to adjust for the length of the work piece (22). A length adjustment holes (17) are provided on the chassis (16) to adjust the position of the structure to accommodate and provide stable support for different length of the work piece. A Guide rod (15) and the chassis (16) are attached to a main frame (18). The main frame (18) is provided with a front levelling screws (19) and a back levelling screws (20) for levelling. It is also provided with fixture to SAW machine fastening means (21) for securing the apparatus with the submerged arc welding (SAW) machine.
Fig-2B illustrates an elevation of the isometric view and a sectional view along A-A of Fig 2A. In the isometric view as illustrated in FIG-2A, the work piece bend portion (22) is fixed for welding. The method of submerged arc welding is carried out by SAW machine using a mounting bolts. The back levelling screws (20) rests on the base of the SAW machine and hence the length of these screws are lesser than the front levelling screws (19). The front levelling screws (19) rests on the floor. Structure consisting vertical column and pipe support (07) along with two horizontal support pipes (08) could be adjusted along guide rods (15) for any required length and could be fastened firmly. The guide rod (15), the chassis (16), the main frame (18), the front levelling screw (19) and the back levelling screw (20) could be adjusted based on the requirement. The angle adjustment screw (10) and socket module provided in additional support facilitates minor angular adjustments and fixed firmly on the chassis (16). The work piece is fixed to the SAW machine using the fastening means (21) and using the length adjustment holes (17) and the bottom support channel (13) the workpiece is fixed accordingly. The top support channel (03) is attached to vertical column support and pipe support (07) by mounting bolt and the height adjusting lock screw (06). The two pipe supporting rollers (01) are fixed to the top support channel by roller mounting bolt and nuts (02). The top support

channel (03) is provided with pitch holes to accommodate different sizes of the work piece.
In one embodiment the submerged arc welding method wherein the short length pipe are in the range of 300mm to 1600mm. In a preferred embodiment the submerged arc welding (SAW) machine fastening means (21) is a mounting bolt.
FIG. 3 illustrates a left side view and an elevation view of an a Work Piece (Short length Pipe) which has to be welded and placed in supporting rollers in position and its sectional view along B-B. in an embodiment of the present invention. In one embodiment the submerged arc welding method for a short length pipe, comprising the steps of providing a work piece to a two pipe supporting rollers (01) which is fixed on a plurality of pitch holes (04) provided on a top support channel (03), positioning a screw and socket arrangement to align minor angular adjustment through an angle adjustment screw (10) to obtain precise parallelism for the work piece. Sliding a bushes enables a top structure to slide on a guide rods (15) to adjust for the length of the work piece. Providing a length adjustment holes (17) on the chassis (16) to adjust the position of the structure to accommodate and provide stable support for different length of the work piece and levelling the workpiece using a front levelling screws (19) and a back levelling screws (20).
In one embodiment the welding carried out by the Submerged Arc Welding (SAW) machine thus reducing the cumbersome process involved in normal welding process. In a preferred embodiment the welding of pipes less than 1600 mm is possible without any extra fit up. Addition of spool pipe by welding with the short length pipe with bridge pieces is eliminated. The time required to complete the job is estimated about 351 minutes which is reduced from 741 minutes. The LPG consumption is reduced from 250 Kg to 10 Kg. Also, number of activities is reduced to 9 from 23. Removal of Bridge pieces by oxy acetylene gas cutting or carbon rod gouging is

eliminated. Grinding, pre heating, filling of metal by welding and LPI at places where bridge pieces were removed in both in short length pipe and in spool pipe are no longer required. Fatigue to workmen due to exposure to high temperature, rework and incessant welding is reduced considerably. Reduced cycle time for the completion of job. Movement of crane is reduced and thereby reduces the dependency on the crane. Finally, this improves surface finish.
The principle of the present invention has been illustrated by way of specific embodiments with reference to the drawings, though the skilled in the art should appreciate that the embodiments are just illustrative but cannot be considered as limiting the scope of the invention that is defined by the accompanying claims.
The advantages of the present invention is given below,
♦ Welding of pipes less than 1600 mm is possible without any extra fit up.
♦ Addition of spool pipe by welding with the short length pipe with bridge pieces is eliminated.
♦ Significant time reduction (from 741 minutes to 351 minutes) to complete the work process.
♦ Reduction in LPG consumption from 250 Kg to 10 Kg
♦ Removal of Bridge pieces by oxy acetylene gas cutting or carbon rod gouging is removed.
♦ Grinding, pre heating, filling of metal by welding and LPI at places where bridge pieces were removed in both in Short length pipe and in spool pipe are no longer required.
♦ There is an improvement in work environment for the worker, as exposure to high temperature, rework and incessant welding has reduced considerably.
♦ Movement of crane is reduced and thereby reduces the dependency on the crane.
♦ Improved surface finish.

WE CLAIM:
1. An apparatus for welding short length pipe in a submerged arc welding
(SAW) machine, comprising:
- a pipe supporting rollers (01) that are fixed to a top support channel (03) by roller mounting bolt and nut (02);
- the top support channel (03) configured to attach to a vertical column and pipe support (07) by a mounting bolt and a height adjustment screw (06), wherein the top support channel (03) is provided with pitch holes (04) to accommodate different sizes of a work piece;
- a structure consisting of the vertical column and pipe support (07) along with two horizontal support pipes (08) adjusted along guide rods (15) for required length and fastening;
- an angle adjustment screw (10) and socket module with additional support (09) provides minor angular adjustments and fixed on a chassis (16)
- a front levelling screws (19) and a back levelling screws (20) for levelling, wherein the back levelling screws (20) is positioned on a base of the submerged arc welding (SAW) machine and a length of back levelling screws (20) are lesser than the front levelling screws (19) and
- a fixture configured to attach the apparatus to the submerged arc welding (SAW) machine fastening means (21) for welding the work piece.

2. The apparatus as claimed in claim 1, wherein the short length pipe are in the range of 300 mm to 1600mm.
3. A submerged arc welding method for a short length pipe in an apparatus as claimed in claim 1, the method comprising the steps of:

(a) providing a work piece to a two pipe supporting rollers (01) which is fixed on a plurality of pitch holes (04) provided on a top support channel (03);
(b) positioning a screw and socket arrangement to align minor angular adjustment through an angle adjustment screw (10) to obtain parallelism for the work piece;

(c) sliding a bushes enables a top structure to slide on a guide rods (15) to adjust the length of the work piece;
(d) providing a length adjustment holes (17) on a chassis (16) to adjust the position of the structure to accommodate and provide stable support for different length of the work piece; and
(e) levelling the workpiece using a front levelling screws (19) and a back levelling screws (20).
4. The apparatus as claimed in Claim 1, wherein the submerged arc welding (SAW) machine fastening means (21) is a mounting bolt.