FIELD OF THE INVENTION
The present disclosure generally relates to a method of fabrication of sleeved tube bend assembly and, in particular, relates to an apparatus for metallic sleeve tube. The present invention preferably may find its application as a connector means to connect two or more bent tubes with perfect alignment of a sleeve with the tube.
BACKGROUND OF THE INVENTION
Background description includes information that may be useful in understanding the present subject matter. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed subject matter, or that any publication specifically or implicitly referenced is prior art.
In thermal power plants, water wall panels or tube assemblies enclose the furnace and absorb the heat and transfer them to the fluid flowing inside of the tubes. Numerous openings are provided on the panel or tube assemblies to insert sensors and electronic and control instruments, man hole door, inspection ports, etc. that are needed at various locations. The dimension and shape of such openings vary according to the functional and design requirements. In the thermal power plants, special type of opening bends are designed with sleeved tube bends.
In the prior art, fabrication of the metallic sleeved tube bend assembly is carried out by the various methods. Existing method allows an inside and outside tube to be bent separately. Existing methods have following deficiencies:

a. Parting the sleeve tube along the bend lines is leading to dimensional inaccuracies
and result in out of shape either by mechanical or chemical cutting.
b. Usage of profile cutting machines or CNC machines is time consuming and cost of
production increase in manifold.
c. To prepare the half tubes with grooves or edge preparation for making welds the
tubes could not be cut into two halves accurately. Hence, it requires additional tube
for each piece and leads to excess material consumption.
d. After fit up over the inner tube, the two halves of the sleeve tube should be welded
to form as a full tube with a full penetration weld which should be carried out
without distortion, since distortion induce residual stress and lead to dimensional
instability. It is very difficult to accomplish in any method of welding due to the
changes in profile.
e. Alternatively, the sleeve could be formed as two halves in a die instead of cutting
into two halves form a full tube. This require different number of dies for each size
and wall thickness. Further, the difficulties in welding the two halves remains the
same.
Since the existing practice is cumbersome and resulting in higher material consumption, weld time, dimensional instability and lead to low productivity, higher cost and more lead time and in some cases when tube is bent about a bending surface, problems frequently arise in twisting of the tube or at least in stretching of the tube so that the circumferential dimensions of both the inner and outer surfaces of the tube move out from the region of the bend.

When sleeve tube is bent, its cross-section may be appreciably off round in the region of the bend and may be a flattened oval. To alleviate such problems, tube is frequently bent over a flexible mandrel conforming to the internal shape of the tube. Thus, if a round tube is to be bent, the internal mandrel will have a circular cross-section and if square tube is to be bent, then the internal mandrel will have a square cross-section.
EP2904301B1 discloses a retaining catch for a socket pipe connection which has a substantially circle-arc-shaped catch body, on which is arranged a protrusion which projects from the catch body. The catch body has a catch cross section in a cross-sectional plane as seen radially in a direction transverse to its circle-arc shaped longitudinal extent. The catch body has a bending portion, and the catch body, along the bending portion, has a reduction cross section which is reduced in size as seen radially in relation to the catch cross section.
EP2872660B1 relates to metal formed parts, a method for producing the formed parts, use of the formed parts and the use of alloys to produce formed parts. Formed parts are produced from copper alloys with the composition (percent by weight) Sn: 2 to 8%, Zn: 2.5 to 13%, Pb: less than 0.25%, Ni: maximum 0.6%, optionally phosphorous, remainder Cu, but at least 84%, and unavoidable impurities, wherein the production of the formed parts includes at least one hot pressing process. The formed parts produced in this manner have outstanding corrosion resistance, very good material properties, high dimensional stability and surface quality and thus are particularly suited for use in water-carrying piping systems.

DE102008031418A1 discloses a method for connecting a hose, in particular a high-pressure hose, with a SAE-head together with the solid flange has having a tubular molded fitting, after the application of the solid flange on the armature by a with a circumferential groove provided with a sleeve is secured to the free end of the fitting upstream pipe section connected, a rim provided with a projection on the hose end applied, the hose end and the socket then pushed in the direction of the sleeve on the armature in the direction of the fitting is deformed under the action of pressure, such that the lip is pressed at least partially into the groove of the sleeve.
DE4433501A1 describes a repair sleeve for a heat exchanger tube of a nuclear steam generator comprises a flexible corrugated tube fitted at its ends with a sealing sleeve consisting of a memory alloy. Such a repair sleeve may also be used in the region of the tube bend in a heat exchanger tube.
Thus, there remains a need for method and apparatus for fabricating a sleeved tube bend assembly which is robust enough to accommodate even higher wall thickness tubes. Also there remains a need for method of fabricating the sleeved tube bend assembly eliminating the parting, forming and welding processes. There remains a need for the method and apparatus for fabricating a sleeved tube bend assembly as per the dimensional requirements.
OBJECTS OF THE INVENTION
In view of the foregoing limitations inherent in the state of the art, some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed herein below.

It is an object of the present disclosure to propose a method for fabricating a sleeved tube bend assembly in which the sleeve tube is firmly fit to the inner tube by bending process, which is not achieved in the conventional forming methods.
It is another object of the present disclosure to propose a method which leads to simplified process and higher productivity and lower cycle time as well as savings in cost.
It is yet another object of the present disclosure to propose an apparatus for easy fit up and perfect alignment of the sleeved tube bend assembly made of any combination of metals and sizes.
It is still yet another object of the present disclosure to propose an apparatus for ensuring faster changeover to enhance productivity
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 THE INVENTION
This summary is provided to introduce concepts related to an apparatus and method for fabrication of a sleeved tube bend assembly. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

The present disclosure relates to an apparatus for fabrication of a sleeved tube bend assembly, comprising an inner tube and a sleeved tube wherein the inner tube is inserted inside the sleeved tube. A bending machine, and a controller are disposed on and supported by a base. A controller includes a memory unit with a plurality angle settings and multi -plane parameters for bending and in electrical communication with said bending machine for providing control signals for bending and the bending machine transmitting bending forces between said inner tube and the sleeved tube subjected to bending, for restricting collapse and limiting deformation of said inner tube and the sleeved tube based on the plurality angle settings and multi -plane parameters and achieves required dimensional accuracy.
The present disclosure further relates to a method of fabrication of a sleeved tube bend assembly, comprising the steps of: providing an inner tube and a sleeved tube wherein the inner tube is inserted inside the sleeved tube disposing a bending machine, and a controller supported by a base. providing a controller including a memory unit with a plurality angle settings and multi- plane parameters and sending a control signals for bending, also in electrical communication with said bending machine and transmitting bending forces from the bending machine to said inner tube and the sleeved tube which are subjected to bending, restricting collapse and limiting deformation of said inner tube and the sleeved tube based on the plurality angle settings and multi -plane parameters for achieving required dimensional accuracy.

In an aspect, a method is designed for fabrication of the metallic sleeved tube bend assembly with metallic sleeve over the metallic inner tube by bending process and eliminating parting, fit up and welding processes. According to the method a perfect enclosing of the sleeved tube bend assembly is ensured by mechanical buffing. This could be used for any metallic tubes of various thickness and diameter of sleeve.
The method also ensures fool-proofing of the fabrication procedure to make the fabrication process of sleeved tube bend assembly error free and no post processing is required as the bending in the bending machine could be made to the required dimensional accuracy.
Other objects, features and advantages of the present disclosure will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as forming the present subject matter, it is believed that the present disclosure will be better understood from the following description taken in conjunction with the accompanying drawings, where like reference numerals designate like structural and other elements, in which:

FIG. 1 shows a prior art process of sleeved fabrication;
FIG. 2 shows a schematic arrangement of the sleeved tube bend assembly in an
embodiment of the present invention;
FIG. 3 shows a sleeved tube bend assembly in an embodiment of the present invention;
and
FIG. 4 shows a flow chart of a method of fabricating the sleeved tube bend assembly in
an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes”, “consisting” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Embodiments explained herein pertain to an apparatus for fabrication of a sleeved tube bend assembly. FIG. 1 shows a prior art process of sleeved fabrication. An inner tube 1 is bent as per required dimension. An outer sleeve tube 2 is made up of two parts.

It is bent separately and cut to required dimensions. The outer sleeve tube 2 is machined and edge prepared for matching the inner tube 1. Fit-up of the outer sleeve tube 2 is done on the inner tube 1. The root gap of 1 mm is maintained throughout sleeve and welding is done.
As can be appreciated by those skilled in the art, the inside tube 1 and the outer sleeve tube 2 is bent separately. The outer sleeve tube 2 is cut into two parts to longitudinally along the bend profile. The cut portion is machined to suit the dimensional requirements to cover half of the size of the inside tubes. The two halves which are prepared separately is fitted over the inside tube 1 and is joined. Then the assembly is welded with the main component.
FIG. 2 shows a schematic arrangement of the sleeved tube bend assembly 200 in an embodiment of the present invention. The apparatus for fabrication of a sleeved tube bend assembly 200 comprising an inner tube 102 and a sleeved tube 104 wherein the inner tube 102 is inserted inside the sleeved tube 104. A bending machine 106, and a controller 108 are disposed on and supported by a base 110. The sleeved tube 104 along with the inner tube 102 is bent in the bending machine 106. The standardized bending parameters are programmed into a controller 108 which is developed for completion of the bending process
The controller 108 includes a memory unit 112 with a plurality angle settings and multi -plane parameters for bending and in electrical communication with said bending machine 106 for providing control signals for bending and the bending machine 106 transmitting bending forces between said inner tube and the sleeved tube 104 subjected

to bending based on the plurality angle settings and multi-plane parameters and achieves required dimensional accuracy. The memory unit 112 includes a pre-programmed speed profile for controlling speed of the bending machine 106. The bending machine 106 uses a hot bending and a cold bending.
FIG. 3 shows a sleeved tube bend assembly 300 in an embodiment of the present invention. The perfect enclosing of the sleeved tube bend assembly 300 is ensured by mechanical buffing. The sleeved tube bend assembly 300 is made up of metallic tubes of various thickness and diameter of sleeve.
In one embodiment, the method of fabricating the metallic sleeved tube bend assembly 300 with metallic sleeve over the metallic inner tube by bending process and eliminating parting, fit up and welding processes. Also, the method of fabricating the sleeved tube bend assembly 300 ensures fool-proofing of the fabrication which makes the process of sleeved tube bend assembly 300 error free and no post processing is required as the bending in the bending machine could be made to the required dimensional accuracy.
In one embodiment the inner tube 102 and the sleeved tube 104 of any diameter is used in the fabrication of sleeved tube bends. The inner tube 102 and the sleeved tube 104 are made up of metallic material and combination of metals. The inner tube 102 and the sleeved tube 104 metallic material is flexible. The inner tube 102 and the sleeved tube 104 is of any length and thickness is used in the fabrication of sleeved tube bends.

In one embodiment the inner tube 102 and the sleeved tube 104 assembled together as per the dimensional requirements and bending with perfect alignment of sleeves. In a preferred embodiment the inner tube 102 and the sleeved tube 104 bending is carried out as a single unit in the bending machine 106.
FIG. 4 shows a flow chart 400 of a method of fabricating the sleeved tube bend assembly in an embodiment of the present invention. The method of fabrication of the sleeved tube bend assembly, comprising the following steps: In the step 402 the bending process is initiated. In the step 404 the method of fabrication of sleeved tube bend assembly is started by providing an inner tube 102 and a sleeved tube 104. In the step 406 inserting the inner tube 102 into the sleeved tube 104. In the step 408 disposing a bending machine 106, and a controller 108 supported by a base 110. In the step 410 providing a controller 108 including a memory unit 112 with a plurality angle settings and multi- plane parameters and sending a control signals for bending, also in electrical communication with said bending machine 106. In the step 412 transmitting bending forces from the bending machine 106 to said inner tube 102 and the sleeved tube 104 which are subjected to bending, based on the plurality angle settings and multi-plane parameters for achieving required dimensional accuracy. In the step 414 the bending process is finished.
In one embodiment the fabrication of sleeved tubes bend assembly 200 by bending process has been developed to achieve maximum efficiency. In a preferred embodiment standardization of process for fabrication of supercritical boiler products are done to ensure continuous improvement. The products which are difficult to fabricate and which involves rework and material wastage are selected to be standardized.

The sleeved tube bend assembly 200 due to its material wastage and long cycle time using this method is improved in time and wastage. The method of fabricating sleeved tubes bend assembly 200 is developed by studying all current process and analyzing each process for elimination/reduction of cycle time, material wastage, machining time and welding. The apparatus and method of fabricating the sleeved tubes bend assembly 200 is established to meet required quality and engineering requirements. The method of fabricating the sleeved tubes bend assembly 200 is capable of fabrication of all lengths and diameters of tubes in bending machines and also cater to fabrication of all types of materials. The method of fabricating the sleeved tubes bend assembly 200 eliminates conventional process of fabrication of sleeves which are inefficient and resource consuming. The method of fabricating the sleeved tubes bend assembly 200 has led to productivity enhancement and improved accuracy of the fabrication process leading to better throughput. The method has been standardized to fabricate the sleeved tubes bend assembly 200.
TECHNICAL ADVANTAGE
The present disclosure proposes an apparatus for fabricating the sleeved tubes bend assembly has improved dimensional accuracies and result in shape either by mechanical or chemical cutting.
The present disclosure proposes a method of fabricating the sleeved tubes bend assembly improves usage of profile cutting machines or CNC machines and reduces time

The present disclosure proposes a method of fabricating the sleeved tubes bend assembly require no additional tube for each piece and leads to less material consumption.
The present disclosure proposes a method for of fabricating the sleeved tubes bend assembly which is carried out without distortion and dimensional stability is achieved.
The present disclosure proposes a method and apparatus of fabricating the sleeved tubes bend assembly which is robust enough to accommodate higher wall thickness tubes thus eliminating the parting, forming and welding processes
The present disclosure proposes a method for of fabricating the inner tube and sleeved tube. The sleeved tubes bend assembly are assembled together as per the dimensional requirements and bending with perfect alignment of sleeves with tubes has been carried out as a single unit in the bending machines
Furthermore, 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.
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.
Furthermore, those skilled in the art can appreciate that 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.
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.
While the foregoing describes various embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof. The scope of the present disclosure is determined by the claims that follow. The present disclosure is not limited to the described embodiments, versions

or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

WE CLAIM:
1. An apparatus for fabrication of a sleeved tube bend assembly, comprising:
an inner tube (102) and a sleeved tube (104) wherein the inner tube (102) is
inserted inside the sleeved tube (104);
a bending machine (106), supported by a base (110);
a controller (108) including a memory unit (112) pre-stored with a plurality of
angle settings and multi -plane parameters for bending and operably connected
to said bending machine (106) for providing control signals for bending; and
the bending machine (106) generating bending forces based on the received
signals representing plurality of angle settings and multi-plane parameters
between said inner tube (102) and the sleeved tube (104).
2. The apparatus as claimed in claim 1, wherein the memory unit (112) includes a pre-programmed speed profile for controlling speed of the bending machine (106).
3. The apparatus as claimed in claim 1, wherein the inner tube (102) and the sleeved tube (104) assembled together as per the dimensional requirements and bending with perfect alignment of sleeves.
4. The apparatus as claimed in claim 1, wherein the inner tube (102) and the sleeved tube (104) are made up of metallic material and combination of metals.
5. The apparatus as claimed in claim 1, wherein the inner tube (102) and the sleeved tube (104) metallic material is flexible.
6. The apparatus as claimed in claim 1, wherein the inner tube (102) and the sleeved tube (104) of any length and thickness can be used in the fabrication of sleeved tube bends.
7. The apparatus as claimed in claim 1, wherein the bending machine (106) is selected to implement a hot bending and a cold bending.

8. A method of fabrication of a sleeved tube bend assembly, comprising the steps of:
providing an inner tube (102) and a sleeved tube (104) wherein the inner tube
(102) is inserted inside the sleeved tube (104),
providing a bending machine (106), and a controller (108) supported by a base
(110);
providing a controller (108) including a memory unit (112) pre-stored with a
plurality of angle settings and multi- plane parameters and set-up to transmit a
control signals for bending, being in electrical communication with said bending
machine (106); and
transmitting bending forces from the bending machine (106) to said inner tube
(102) and the sleeved tube (104) which are subjected to bending, based on the
plurality of angle settings and multi-plane parameters for achieving required
dimensional accuracy.
9. The method as claimed in claim 8, wherein the inner tube (102) and the sleeved tube
(104) is of any length and thickness, diameter which is used in the fabrication of
sleeved tube bends.