Method for Producing a Number of Pipes Having a Predefined Pipe Diameter, Pipe, and Piping System

Abstract

The invention relates to a method for producing a number of pipes (100) with a predetermined pipe diameter. The method includes feeding multiple pipe parts (101, 102) with the predetermined pipe diameter to a welding station (53), aligning in each case a first pipe part (101) and a second pipe part (102) coaxially with respect to one another and axially adjacent to one another, welding the pipe parts (101, 102) by means of a fully encircling weld seam (109) to form a pipe run (104), conveying the pipe run (104) to a cutting station (57) in a machine direction (A) downstream of the welding station (53), and cutting off the number of pipes (100) in a respectively designated length from the pipe run (104).

Claims

1. A method for producing a number of pipes with a predetermined pipe diameter, comprising: feeding multiple pipe parts with the predetermined pipe diameter to a welding station, aligning in each case a first pipe part and a second pipe part coaxially with respect to one another and axially adjacent to one another, welding the pipe parts by a fully encircling weld seam to form a pipe run, conveying the pipe run to a cutting station in a machine direction downstream of the welding station, and cutting off the number of pipes in a respectively designated length from the pipe run.

2. The method as claimed in claim 1, wherein, after the cutting-off of the number of pipes, a residual pipe part remains, and the method comprises: transferring the residual pipe part into a buffer store.

3. The method as claimed in claim 1, wherein at least one of the first and second pipe parts is guided from a pipe store to the welding station.

4. The method as claimed in claim 3, comprising: checking whether a residual pipe part of the predetermined diameter is available in a buffer store, and if so: feeding the at least one of the first and second pipe parts from the pipe store and feeding the residual pipe part from the buffer store to the welding station.

5. The method as claimed in claim 4, wherein the method is carried out in batch-based fashion, wherein a batch run comprises a designated number of pipes to be produced, and the method comprises: determining a total length of the designated number of pipes, determining a length of the residual pipe part in the buffer store, if present, and determining a required quantity of pipe parts to be fed from the pipe store as: total length of the designated number of pipes minus the length of the residual pipe part, divided by the predefined pipe length of the pipes in the pipe store.

6. The method as claimed in claim 1, wherein the pipe parts each comprise a wall, and the wall comprises in each case an encircling edge surface, and the aligning comprises: aligning the encircling edge surface of the first pipe part and the encircling edge surface of the second pipe part with one another, and the welding comprises: welding the first pipe part to the second pipe part along the encircling edge surfaces, wherein a fully encircling weld seam is generated which comprises a root extending on the inside of the pipe run.

7. The method as claimed in claim 6, wherein each of the edge surfaces of the first pipe part and of the second pipe part comprise an encircling inner edge, and the welding comprises: forming the root of the weld seam with a thickness that completely encompasses both inner edges, wherein the root of the weld seam protrudes radially inward from an inside of the wall of the first and/or second pipe part by a predetermined maximum value, wherein the predetermined maximum value amounts to 0.7 times the wall thickness of the pipe parts or less.

8. The method as claimed in claim 1, wherein the cutting-off step comprises: generating at least one of the edge surfaces of a residual pipe part by plasma cutting.

9. The method as claimed in claim 6, furthermore comprising: cleaning the edge surface before the welding.

10. The method as claimed in claim 9, wherein the cleaning comprises removing metal oxides and loose particles from the at least one edge surface by brushing.

11. The method as claimed in claim 1, wherein the method is a method for producing a designated number of polymer-enhanced pipes, comprising: applying a polymer-based layer on the inside of the pipes, wherein the polymer-based layer completely covers the inside of the pipes and the root of the weld seam.

12. The method as claimed in claim 11, wherein the application of the polymer-based layer is performed by dipping of the pipeline element into a dip bath which contains a corresponding coating material.

13. The method as claimed in claim 11, wherein the pipe parts are formed from a metal suitable for chemical autodeposition including a ferrous and/or zinc-containing metal, and the applying the polymer layer on the inside of the pipe comprises: coating by chemical autodeposition and dipping of the pipe into a dip bath which contains a polymer-based chemical autodeposition material.

14. The method as claimed in claim 13, wherein the autodeposition material comprises polymer constituents which are ionically bonded to a wall of the pipe parts and to the root of the weld seam, and is present as an aqueous emulsion or dispersion.

15. The method as claimed in claim 14, wherein the autodeposition material is acidic, and comprises a starter material in the form of metal halides by which the polymer constituents are destabilized.

16. The method as claimed in claim 13, wherein the autodeposition material comprises, as polymer constituent, autodepositionable polymers selected from the list comprising: i) epoxides, ii) acrylates, iii) styrene acrylates, iv) epoxy acrylates, v) isocyanates, urethanes, or polyurethanes, vi) polymers with a vinyl group or polyvinylidene chloride, or iv) a combination of two or more of i), ii) or iii), which are crosslinked to one another via an isocyanate or via a urethane.

17. The method as claimed in claim 13, wherein the dipping is performed in one or more dipping processes and is continued until such time as the polymer-based layer applied to the inside of the pipe comprises a thickness in a range from 7 μm to 80 μm.

18. A pipe, comprising: a first pipe part, a second pipe part, wherein the pipe parts are aligned coaxially with respect to one another and connected by an encircling weld seam, wherein the weld seam comprises a root extending on an inside of the pipe, and a polymer-based layer on the inside of the pipe, wherein the polymer-based layer completely covers the inside of the pipe and the root of the weld seam.

19. The pipe as claimed in claim 18, wherein the root of the weld seam completely encompasses edge surfaces of both pipe parts, and protrudes radially inward from an inside of the wall of the first and/or second pipe part by a predetermined maximum value, wherein the predetermined maximum value amounts to 0.7 times the wall thickness of the hollow bodies or less.

20. The pipe as claimed in claim 18, wherein the pipe parts are formed from a metal suitable for chemical autodeposition, including a ferrous and/or zinc-containing metal, and wherein the polymer-based layer contains a metallic constituent including metal ions including iron ions and/or zinc ions.

21. The pipe as claimed in claim 20, wherein the polymer-based layer, comprises as polymer constituent, one or more autodepositionable polymers selected from the list comprising: i) epoxides, ii) acrylates, iii) styrene acrylates, iv) epoxy acrylates, v) isocyanates, urethanes, or polyurethanes, vi) polymers with a vinyl group or polyvinylidene chloride, or iv) a combination of two or more of i), ii) or iii), which are crosslinked to one another via an isocyanate or via a urethane.

22. The pipe as claimed in claim 21, wherein the polymer-based layer comprises a thickness in a range from 7 μm to 80 μm.

23. A pipeline system of a fire extinguishing installation comprising a number of pipes which are coupled to one another, wherein one, multiple or all pipes are designed as claimed in claim 22.

24. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The invention will be described in more detail below with reference to the appended figures and on the basis of preferred exemplary embodiments.

[0076] FIG. 1 shows a schematic layout of an installation for carrying out the method according to the present invention.

[0077] FIG. 2 shows a schematic flow diagram of the method according to the invention according to a preferred exemplary embodiment.

[0078] FIG. 3 shows a further schematic flow diagram of the method according to the invention as per FIG. 2.

[0079] FIG. 4 shows a schematic partial illustration of a pipe according to a preferred exemplary embodiment.

MODE(S) FOR CARRYING OUT THE INVENTION

[0080] FIG. 1 shows an installation 50 for producing pipes with a predetermined diameter and respectively designated pipe lengths. The installation 50 has a pipe store 51 in which a multiplicity of pipe parts 101 with a standard length of for example 6 m are stored.

[0081] The installation also has a welding station 53. The welding station has at least one welding tool 55, which is configured to weld together pipe parts 101, 102 that are fed to it, such that a fully encircling weld seam 109 (cf. FIG. 4) is formed which connects the adjacent pipe parts 101, 102 to one another such that a root (112) of the weld seam is formed on the inside of the pipe parts 101, 102.

[0082] The welding station 53 is configured to form a virtually endless pipe run 104 from the individual pipe parts 101, 102 that are fed to it. In preferred embodiments, the welding tool 55 may be designed to be manually operable, partially automated or fully automated.

[0083] The installation 50 furthermore has a cutting station 57. The cutting station 57 has a parting tool 59, for example a device for plasma cutting. The cutting station 57 is configured to use the cutting tool 59 to cut off pipes 100 in a respectively designated length from the pipe run 104 that is fed to it.

[0084] The installation 50 furthermore has a conveying section 61 which is configured to convey the pipe parts 101, 102 in a machine direction A downstream from the pipe store 51, firstly to the welding station 53 and then to the cutting station 57. The conveying section 61 may be in the form of a singular device or in the form of a combination of several devices cooperating with one another. For example, the pipe parts 101, 102 or pipe runs 104 and pipes 100 are transported by means of belt conveyors or the like.

[0085] The installation 50 furthermore has a buffer store 63. The buffer store 63 is configured to temporarily accommodate residual pipe parts 102 that remain after a number of pipes 100 required for an order have been cut off from the pipe run 104.

[0086] If a number of pipes 100 with a predetermined diameter are to be produced with the installation 50, the remaining pipe parts 102 situated in the buffer store can be removed from there and fed to the conveying section 61 upstream of the welding station 53 in order to be welded together with the pipe parts 101 situated in the pipe store to form a pipe run.

[0087] If the buffer store 63 does not have any residual pipe parts 102 in the predetermined pipe diameter, the pipe run may also be formed exclusively with pipes 101 from the pipe store 51.

[0088] The buffer store 63 is preferably configured to accommodate residual pipe parts 102a, 102b of different pipe diameters.

[0089] FIG. 2 shows the basic method sequence of the method according to the invention according to a preferred exemplary embodiment.

[0090] In a first step 1, an order is firstly issued to produce a predetermined number of pipes 100 with a predetermined diameter. Each of the pipes 100 to be produced has a designated length, which may differ from pipe to pipe or may also be identical.

[0091] After the order has been received, it is optionally ascertained in a next method step 3 how large the total length of all of the pipes 100 to be produced is and how many pipe parts 101 from the pipe store 51 are completed in order to complete the order.

[0092] If a residual pipe part 102 is still present in the buffer store 63, this is included in order to complete the order. Any residual pipe part still remaining completion of the order is finally fed to the buffer store 63 again.

[0093] If computer-aided order planning is used which calculates the raw material requirement, and if it is ascertained in a subsequent method step 5 that one or more residual pipe parts 102 of the predetermined pipe diameter are still in stock in the buffer store 63, the length of the residual pipe parts available in the buffer store 3 can be subtracted from the required total length. The result divided by the length of the pipe parts 101 situated in the pipe store 51 then gives the number of pipe parts 101 required from the pipe store 101.

[0094] If it is ascertained in method step 5 that one or more residual pipe parts 102 of the predetermined diameter are available in the buffer store 63, these are fed in a next method step 7 to the conveying section 61.

[0095] In addition, the required pipe parts 101 are fed in succession from the pipe store 51 to the conveying section 61 in a method step 9. If no residual pipe parts 102 of the predetermined diameter are available in the buffer store 63, the need for pipe parts for the order placed is covered exclusively with pipe parts 101 from the pipe store 51. The pipe parts 101 and any residual pipe parts 102 are, in a next step 11, fed to the welding station 53 and welded together.

[0096] After the welding, the pipe run 104 generated as a result of the welding is fed to the cutting station 55, and in a next method step 21 the pipes 101 are cut off from the pipe run 104 in the required, respectively designated lengths. If a residual pipe part 102 remains after the required number of pipes 100 has been cut off, this is fed to the buffer store 63 in a next method step 22.

[0097] After the cutting-off process, it is determined in a selection step 23 whether the cut-off pipes 100 can be directly transferred onward for surface enhancement or whether further welding steps, in particular the attachment of weld-on parts to the pipes, should take place first. If the pipes are to be processed further without weld-on parts, they are removed from the conveying section 63 after the cutting-off process from step 21 and, in a next method step 29, are prepared for the surface enhancement.

[0098] If the selection is made that the cut-off pipes 100 are to be additionally processed further by attachment of further weld-on parts, these are fed as second hollow bodies to a method step 25b, cf. FIG. 3.

[0099] FIG. 3 schematically illustrates the additional attachment of weld-on parts to the pipes 100. Firstly, in steps 25a, 25b, a first hollow body, for example a pipe connector for receiving a sprinkler, and a pipe 100 generated from the pipe run 104 as a second hollow body, are provided. Following this, in a next method step 39a, b, edge surfaces are provided on the hollow bodies, preferably by means of plasma cutting. In steps 39a, b, the hollow bodies are provided with edge surfaces either on one or both of their end faces or on a wall section which is spaced apart from the respective end faces, said wall section being in the form of a cutout.

[0100] In a method step 41a, b that follows, the first and second hollow bodies are cleaned on the edge surfaces, preferably by means of a rotationally driven brush. If plasma cutting was used in the previous step to generate the edge surfaces, metal oxides and loose particles and burrs formed as a result of the brushing are removed as substantially as possible.

[0101] In a next method step 43, the first hollow body and the second hollow body are aligned with one another such that in each case one edge surface of one hollow body is aligned and arranged as closely adjacent as possible to a corresponding edge surface of the respective other hollow body. The alignment of the hollow bodies with respect to one another may be performed manually or by means of a single-jointed or multi-jointed robot.

[0102] In a next method step 45, the previously aligned hollow bodies are welded to one another along the mutually aligned encircling edge surfaces, such that a fully encircling weld seam is generated which has a root extending on the inside of the pipe. A single-layer weld seam is preferably applied.

[0103] Following the welding, the hollow bodies that have been welded together are, as tubes with weld-on parts, fed back to the method sequence in a method step 27 through which the tubes 100 without weld-on parts also pass.

[0104] In a method step 29, which in turn may have multiple substeps that are not illustrated in any more detail, the pipes 100 are prepared for the subsequent coating. The preparation comprises the cleaning of the pipes in one or more dip baths in which, for example, pickling or rinsing media such as demineralized water can be stored. The exact number and arrangement of the preparatory steps depends on the specifications of the coating material to be used.

[0105] The hollow bodies prepared in step 29 are then chemically coated in a next method step 31 in one or more dipping operations by means of an autodeposition method. The result of the dipping is that the entire inside including the weld seam, but also the outside of the hollow bodies, is substantially completely coated.

[0106] Following the coating of the hollow bodies and of the weld seam with the polymer-based layer, a thermal aftertreatment process takes place in a step 33. The step 33 may include one or more substeps, in each of which a flash-off or tempering with predetermined temperatures and tempering periods is performed (low-temperature tempering or high-temperature tempering). Optionally, the pipes coated and aftertreated in this way, which have been generated from the pipe parts, may be powder-coated in a step 35. The powder coating is also preferably cured again in a drying process in step 33.

[0107] Subsequently, in step 37, the pipe is conveyed out of the production process and is ready for use.

[0108] The method step 33 for the thermal aftertreatment of the pipes is shown as a single step for the sake of simplicity. It is however possible for multiple successive heat treatment stages to be performed in step 33, which are performed in one or in multiple different devices.

[0109] The welding processes according to steps 11, 45 may for example be optimized in that, in a measuring step 13, which may be performed at any time between steps 7, 9 and 25a, b respectively and the respective welding step 11, 45, the diameters of the pipe parts and the wall thicknesses of the pipe parts, in particular in the region of the edge surfaces, are measured.

[0110] Optionally, a measurement is carried out online, for example optically by means of gap detection, directly in the method step of the edge surface generation, and, on the basis of the measured variables, the welding parameters are then adapted online in order to compensate for any ascertained deviations of the measured geometry from the starting geometry for which the original welding parameters were stored. This makes it possible for the effects of the deviations, for example any out-of-roundness of the hollow body, to be compensated in the welding process itself.

[0111] Depending on the measured parameters, a parameter set for optimal application of the weld seam is preferably selected in a method step 15 from a predefined value table. The parameters that are stored in the predefined value table for each diameter and each wall thickness preferably comprise the feed rate, the material of the welding filler metal, and the type of welding. If, for example, arc welding is selected as the welding type, the parameters of the welding tool 55 also include the voltage, the feed rate of the welding wire, etc.

[0112] In a subsequent step 17, the previously determined parameters are preferably read into the welding tool or, if welding is to be performed manually, provided to the operator in order that the welding of the first and second hollow bodies to one another can be performed in the subsequent step 19.

[0113] FIG. 4 illustrates a pipe 100 or optionally a part of the pipe run 104 in the region of the encircling weld seam 109 generated in the welding station 51. The pipe parts 101 and 102 are arranged coaxially with respect to one another and axially adjacent to one another. In the non-welded state, the pipe parts 101 and 102 each have an edge surface 115, 117 facing toward the other pipe part. After the weld seam 109 has been applied according to the invention, a root 112 of the weld seam 109 extends in fully encircling fashion in a circle within the pipe run 104 or pipe 100.

[0114] In the non-welded state, the edge surfaces 115, 117 are still each delimited by an encircling inner edge 121, 123. The encircling inner edges 121, 123 are completely encompassed by the root 112 of the weld seam 109 in the welded state. Instead of an angular, sharp transition between the pipe parts 101, 102, the root 112 of the weld seam now forms a relatively smooth transition. Here, the root 112 of the weld seam 109 protrudes radially within the wall 107 of the pipe 100 or pipe run 104 by a predetermined maximum value t1. The extent to which the root 112 protrudes inward is determined from the pipe diameter of the pipe parts 101, 102, the material thickness of the wall 107, and the welding parameters of the welding tool 55.

[0115] In the course of preliminary tests, it is ascertained for the predetermined pipe diameter what welding parameters can be used to form the root 112 with the desired depth t1, see above. Depending on what pipe diameter is present for the respectively present order, the suitable parameter set is selected from the list determined in advance and the welding process is carried out therewith. The procedure is basically the same irrespective of whether the welding is performed in automated, partially automated or manual fashion.

[0116] Furthermore, in FIG. 4, reference designation 111 indicates the polymer-based protective layer applied to the inside of the pipe 100 at the end of the method, which protective layer has the characteristics described above in the general part. In the interior of the pipe 100, the pipe 100 has a polymer-based layer 111 which extends all the way along the insides of the hollow bodies 101, 102 and which also at any rate completely covers the encircling weld seam 109 on the inside of the pipe 100. If the pipe has been coated in a dipping process, the outer surface of the first and second hollow bodies 101, 102 and the weld seam 109 are at least substantially also covered by the polymer-based layer.