Claims:WE CLAIM:

1. A high pressure high temperature steam generator link (100) comprises clamping (101), trailing (102) and arc (103) integrally connected to form a single structure of pipe involving angle of bend (104) and bend radius (105).

2. The high pressure high temperature steam generator link as claimed in claim 1, wherein the bend radius is approximately 1.5 times the radius of the original/corresponding elbow.

3. A process for manufacturing a high pressure high temperature steam generator link comprising steps of:

a. Marking of bends in pipe
b. Preheating of bends
c. Bending in incremental bender
d. Heat treatment.

4. The process for manufacturing a high pressure high temperature steam generator link as claimed in claim 3, wherein the bending is followed by dimensional check, post forming heat treatment, testing and final machining.

5. The process for manufacturing a high pressure high temperature steam generator link as claimed in claim 3 or 4, wherein for the increased bend radius, the tangential lengths of the bend are adjusted with adjacent connection thereby maintaining the overall length of the original span.

6. The process for manufacturing a high pressure high temperature steam generator link as claimed in claim 3-5, wherein for the incremental bending, the radius is increased that R/D (radius to diameter) is = 1.5 times the radius of the corresponding elbow.

7. A high pressure high temperature steam generator link and manufacturing thereof as claimed in any of the preceding claims is associated with the advantageous features such as herein described.
, Description:A high pressure high temperature steam generator link and manufacturing thereof
FIELD OF INVENTION
[001] The present invention relates to High Pressure High Temperature Steam Generator Link and Manufacturing thereof.

[002] Different components of the High Pressure High Temperature Steam Generator are interconnected by Links. The routing of the Links is provided with Elbows of varying angles for change of axis. The present invention relates to manufacturing of such Links by replacing Elbows into Incremental Bends.

BACKGROUND OF THE INVENTION

[003] Links are implemented as interconnection between different components of High Pressure High Temperature Steam Generator such as Desuperheaters, Connecting Sphere, Headers and Recirculation Pumps. The routing of the Links is provided with the help of Elbows of varying angles for change of axis. Elbows are made of Carbon steel and alloy steels with Outer diameter ranging from 219.1 to 609.6 mm, thickness ranging from 36 to 60 mm and angles from 45 degrees to 90 degrees weighing around 80 kg to 3000 kg depending on the size. Said links are manufactured by forming of Elbow and Butt joint welding of Elbow with pipe. Manufacturing process includes Pipe marking for Elbow pressing, pre heating and forming of Elbow, post forming heat treatment (PFT), shot blasting, NDE (Non Destructive Examination) testing, statutory clearance, cutting to required angle, edge preparation (EP), butt joint fit-up with pipe, butt joint welding, post

weld heat treatment (PWHT), dimensional testing, NDE testing, final machining. Thus this process consumes lot of time and also requires more resources and consumables. Hence, an alternative method is required to manufacture Links in shortest possible time at cost effective rate.

[004] Now, reference may be made to fig. 1 illustrating prior art, wherein fig 1 shows the assembly of the elbow with connecting pipes on either side thereof. According to the existing technology, the assembly comprises an elbow (2) disposed between two pipes (1, 3) i.e. the elbow (2) is interposed between said pipes (1,3). The three parts (1, 2, 3) are joined together by means of butt joint (4, 5) there between. The butt joints (4) and (5) are completed by welding after edge preparation. This process includes edge preparation of pipes (1), (3) and forming, cutting, testing and edge preparation of elbow (2). The edge prepared pipes and elbow are joined by means of welding followed by heat treatment so as to yield final product constituting link. This process takes 9 to 15 days to complete depending on the size of the link.

[005] The proposed application introduces novel link to replace the aforesaid elbow. So that, issues of the known art(s) can be addressed thereby.

OBJECTS OF THE INVENTION

[006] An object of the invention is to propose a high pressure high temperature steam generator link and manufacturing thereof which obviates shortcomings of the prior art(s).

[007] Another object of the invention is to propose a high pressure high temperature steam generator link and manufacturing thereof which is simple.

[008] Still another object of the present invention is to provide a high pressure high temperature steam generator link and manufacturing thereof which eliminates elbows.

[009] Yet another object of the present invention is to provide a high pressure high temperature steam generator link and manufacturing thereof which is cost effective.

[010] Further object of the present invention is to provide a high pressure high temperature steam generator link and manufacturing thereof which reduces the overall cycle time.

SUMMARY OF THE INVENTION

[011] Accordingly, there is provided a high pressure high temperature steam generator link (100) comprises clamping (101), trailing (102) and arc (103) integrally connected to form a single structure of pipe involving angle of bend (104) and bend radius (105).

[012] The bend radius is approximately 1.5 times the radius of the original/corresponding elbow.

[013] A process for manufacturing a high pressure high temperature steam generator link comprising steps of:

a. Marking of bends in pipe
b. Preheating of bends
c. Bending in incremental bender
d. Heat treatment.

[014] The bending is followed by dimensional check, post forming heat treatment, testing and final machining.

[015] For the increased bend radius, the tangential lengths of the bend are adjusted with adjacent connection thereby maintaining the overall length of the original span.

[016] For the incremental bending, the radius is increased that R/D (radius to diameter) is = 1.5 times the radius of the corresponding elbow.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[017] Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings of the exemplary embodiments and wherein:-

Fig. 1 shows: Elevation of conventional assembly.
Fig. 2 Shows: Elevation of a high pressure high temperature steam generator link in accordance with present invention.
DETAIL DESCRIPTION OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS OF PREFERRED EMBODIMENTS

[018] The present invention makes a disclosure regarding a technology pertaining to a high pressure high temperature steam generator link and manufacturing thereof. For the same, reference may be made to figure 2 illustrating novel link proposed by this application.
[019] The high pressure high temperature steam generator link (100) forms a single structure. Said link includes three components, namely clamping (101), trailing (102) and arc (103) integrally connected to each other as shown. This constitutes a single piece of pipe. The link involves an angle of bend (104) and bend radius (105) as shown. Here, the bend radius is approximately 1.5 times the radius of the original/corresponding elbow. Thus, for the purpose of incremental bending the radius is increased such that R/D (radius to diameter) is equal to or greater than 1.5 of the existing value of 1 in case of elbow.

[020] Manufacturing of the link of the instant invention involves process of incremental bending.

[021] The incremental bending of pipes is introduced to eliminate the butt welding of elbow with connecting pipes on either side.

[022] The process involves the following steps:

[023] Marking of pipes for bending, pre heating and bending in incremental bender, dimensional check, post forming heat treatment, NDE testing and final machining. This process of manufacturing the link is conducted in two days.

[024] Thus, the replacement of elbows with bends also minimizes the pressure drop which in turn increases the overall working efficiency of the high pressure high temperature steam generator.

[025] For the increased bend radius, the tangential lengths of the bend are adjusted with adjacent connection thereby maintaining the overall length of the original span.
[026] The total time for manufacturing links using incremental bending including heat treatment takes only 3 days to complete. Thus, the cycle time for manufacturing the link is reduced drastically with improved efficiency and elimination of the welding.

[027] Thus, the invention provides manufacturing of Links with novel process of Incremental bending in place of Elbow forming. The incremental bending operation has replaced the more time and resource consuming elbow forming process. The proposed link also reduces the pressure drop and proves to be technically efficient. The process has eliminated butt joint welding and the related additional testing requirements. With the change in radius to nearly 1.5 times the original radius of the Elbow, the final product is manufactured with conformance to all the critical hold points such as thinning, minimum thickness, hardness of bend to withstand the working temperature, pressure and physical loading without deviation from the desired operation of the Link. Thereby there is substantial savings in manpower by avoiding two circumferential welding in this process and hence the productivity is increased.

[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 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”.

[029] It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-