WO2001073412A1

WO2001073412A1 - Method and system for the visual inspection and assessment of endless weld seams in pipe conduits

Info

Publication number: WO2001073412A1
Application number: PCT/EP2001/003590
Authority: WO
Inventors: Friedel Paul Kalberg
Original assignee: Friedel Paul Kalberg
Priority date: 2000-03-31
Filing date: 2001-03-29
Publication date: 2001-10-04
Also published as: EP1272831A1

Abstract

The invention relates to a method for the visual inspection and assessment of endless weld seams in pipe conduits. To this end, the pipe conduit ends (En*, En+1**) of two pipe conduits portions (Rn, Rn+1) to be linked are concentrically aligned relative each other and clamped by a clamping device (1) that acts upon the respective inner side of the pipe conduit ends. Once the base of the weld seam (S) is welded, the clamping device (1) is released and displaced in the direction of the axis of the pipe in such a manner that an image recording device (2; 2*) for recording the image of the weld seam (S), and for transmitting and reproducing it, disposed axially laterally on the tensioning device (1), is positioned in the imageable area of the weld seam. The weld seam (S), when looked at in the peripheral direction, is reproduced in weld seam sections (Sa). The invention further relates to a system for the visual inspection and assessment of endless weld seams in pipe conduits.

Description

Process and arrangement for the visual inspection and assessment of circular welds in pipelines

TECHNICAL AREA

The invention relates to a method and an arrangement for the visual inspection and assessment of circular welds in pipelines.

STATE OF THE ART

When welding pipelines that are composed of individual pipeline parts of a certain length, in particular pipelines, it is absolutely necessary to check all or at least a certain proportion of the circular weld seams of the pipeline. So far, this has been done by subjecting the circular weld seam, which generally consists of several welding layers, to an X-ray inspection after its completion. Structural changes influencing corrosion resistance due to inadmissible heating can be determined using the tarnishing colors in the area of the weld seam. For this purpose, the weld seam is additionally subjected to a visual inspection using an endoscope from the side of the last welded pipe part and from the inside of the pipe. During the visual inspection, you can also get a picture of the nature, completeness and root sag.

Both the X-ray and the endoscopic inspection are generally not manageable by the welder and require specially trained specialist staff. Detected errors increase the proportion of weld seams to be inspected in the future, if the inspection modalities provide for the inspection of a certain proportion of the weld seams.

Particular emphasis is placed on the above-mentioned testing and documentation of the circular welds in energy, energy supply, pharmaceutical and food and beverage technology. Especially in pharmacy and food and beverage technology Not only is a root free of pores, binding defects and tarnishing colors required, but there are also particularly stringent requirements for the root sag, since the pipeline systems in question must often be piggable.

Particularly high demands are placed on the quality of the weld seams, their completeness, their sagging of the roots and the formation which, if not properly carried out, will lead to tarnishing and the associated susceptibility to corrosion, particularly in the area of natural gas production using pipelines. Pipeline systems are increasingly being put into operation here, in which the natural gas to be extracted is conveyed directly in the condition and the pressure that occurs during the extraction and without drying. This wet, high-pressure natural gas is corrosive due to its composition. Pipelines are therefore required which, on the one hand, have the necessary corrosion resistance at least on the inside of the pipe and which, on the other hand, have to withstand the high delivery pressure. For reasons of strength, thick-walled pipes are therefore required, which must have the necessary corrosion resistance. Since the thick-walled tube cannot be manufactured from corrosion-resistant material for reasons of cost, tubes are used that consist of a thin-walled, corrosion-resistant tube on the inside and a thick-walled steel tube that does not have to be corrosion-resistant on the outside. The welding of the corrosion-resistant, thin-walled tube on the inside must be given particular attention from the above-mentioned points of view. The root must be completely welded, it must be free from binding defects and no tarnishing colors should be visible, since the latter would be an indicator of insufficient formation with protective gas, which means that the necessary corrosion resistance is no longer available at these points. The weld seams of such pipes are generally subjected to an X-ray inspection after root welding. In addition, for the aforementioned reasons, it is advisable and advisable to also inspect the welds endoscopically. The circular weld seams of the pipes described above, which consist of a composite material, therefore require very careful testing and assessment; in any case, the result must be adequately documented.

The object of the present invention is to provide a method and an arrangement for its implementation with which the visual inspection and assessment of circular welds in pipelines can be carried out faster, more simply and more cost-effectively than with methods according to the prior art.

SUMMARY OF THE INVENTION

This object is achieved with the features of claims 1 to 14.

Due to the spatial proximity between an internal clamping device for the mutual alignment and clamping of the pipe ends to be connected to one another of two pipe parts, the internal clamping device at the same time also ensuring a sufficient and secure supply of forming gas at the weld seam, and a visual image acquisition device, the task at hand, namely a Quick, simple and inexpensive visual inspection and assessment of the just completed circular weld seam possible. Aligning and tensioning the pipe ends to be connected from the inside and with the greatest possible clamping force is a prerequisite for a root-and-socket weld that is free of binding errors, otherwise, since there are no precisely round pipes, the offset of the pipe walls to be connected that results from out-of-roundness can lead to binding errors , Such an internal clamping device is known for example from DE 90 05 893 U1. Furthermore, DE 94 17 101 U1 describes, among other things, an internal clamping device relating to this in the context of a device for orbital guiding and for driving a welding tool when welding the ends of a pair of tubes. After completion of the first position of the weld seam, the root, the internal clamping device is loosened and, preferably away from the weld seam, is moved into the pipeline, so that the image capturing device arranged axially laterally on the internal clamping device for image acquisition, transmission and display of the The weld seam is positioned in the reproducible area of the weld seam, either directly under the weld or slightly axially laterally offset below the weld seam just completed. In this position, a partial or complete and complete mapping of the root weld is possible. If there is a slight axial lateral offset of the image acquisition device, the root sag in particular can be assessed very well. In the proposed method, the weld seam, viewed in the circumferential direction, is depicted in weld seam sections in each of the two process variants, the respective position of the image, based on a defined reference point or starting point, being recorded for each image of a weld seam section generated in this way. The image and its position are displayed for visual inspection and assessment and / or read out and saved for the purpose of documentation.

To document the weld seam in general and to localize any defects in the root area in particular, it is necessary to specify the position of the weld seam section shown. The position determination to be carried out is particularly simple and advantageous if an image center of the respective image, viewed in the circumferential direction and in relation to the reference point or starting point, is used to generate the position. For fault localization, a first image capturing device can be moved in one or the other circumferential direction to such an extent that a specific fault location of the weld seam to be localized is positioned in the center of the image. The center of the picture is known and recorded in its respective position. According to a further proposal, all weld seam sections of a weld seam are captured with a second image capturing device which is arranged in a fixed manner, the positions of the Weld seam sections, based on the reference or starting point, are predetermined by the arrangement and are therefore known in each case.

The present process is designed in two process variants. In the first method variant, the images of the weld seam sections are generated step by step, one after the other, and the sequence of the images results in a complete, consistent image of the weld seam.

A modification of this first method consists in that the images of the weld seam sections are produced continuously, progressively, so that the sequence of the images likewise results in a complete, consistent image of the weld seam. The "traversing" or "scanning" of the weld seam and the examination and assessment of the images in the above-mentioned step-by-step or continuous procedure can, as is also proposed, take place manually or automatically in a controlled manner. The same applies to reading out and storing the image on a suitable storage medium.

The second variant of the method is that the images of the weld seam sections are generated simultaneously, and that the combination of the images results in a complete, consistent image of the weld seam. As a result, a complete image of the weld over 360 degrees is achieved at the same time. The images of the weld seam recorded at the same time are read out, on the one hand, in a predetermined order, which represents the circular weld seam seamlessly and logically, and stored on a suitable storage medium. In addition, the individual images can be displayed simultaneously on a multiply divided image output unit or one after the other and can be called up in accordance with the last-mentioned method variant, in accordance with the recorded course of the circular weld seam. However, the sequence can also be selected as desired, for example in order to be able to subject a specific weld seam section to a repeated test and assessment. The individual images can be called up, displayed and also saved, as is also provided, manually or automatically. In order to be able to localize a possible fault location in the weld seam, it is proposed according to a first embodiment of the method to image the fault location in a center of the image and to define the position indicated for this center as the fault location. In this case, the fact already mentioned above is advantageously used that the center of the image of the respective image, viewed in the circumferential direction and in relation to the reference or starting point, is used to generate the position. The location of the defect is accordingly carried out in a simple manner in that the respectively determined defect is positioned in the center of the picture by visual inspection and that the position of the center of the picture to be displayed is now inevitably the position of the defect. According to a second embodiment of the method, the defect location is assigned to a weld section in question and the position indicated for the latter is defined as the defect location position.

It can be advantageous if the position of the defect is used to position a welding tool for producing the weld seam. Such a procedure can be largely automated. For this purpose, the position of the defect is read out in a control device for the welding tool.

The first arrangement according to the invention for testing and assessing circular weld seams in pipelines is based on what is known as an internal tensioning device according to the prior art (cf. DE 90 05 893 U1; DE 94 17 101 U1), the two pipe ends to be connected to each other at their ends Aligns and clamps each other concentrically on the inside and which aligns itself concentrically to the axis of the pipe ends, and arranges coaxially to the axis of the tensioning device and axially laterally offset from it a first image acquisition device for image acquisition, transmission and display of the weld seam. This first image capturing device has a circumferential direction around the weld seam and at a fixed radial distance therefrom. fend drivable first image acquisition unit. In addition, the proposed arrangement has an angular path measuring device which detects a circumferential angle which the first image acquisition unit has covered in relation to a defined reference point or starting point.

For handling and controlling the proposed first arrangement, the latter is further configured such that the first image capturing device is connected to an image output unit, a control unit and a storage unit.

A second arrangement according to the invention for the visual inspection and assessment of circular weld seams in pipelines is also based on the internal clamping device mentioned above in that a second image capture device is provided for the image capture, transmission and display of the weld seam, this second image capture device being coaxial with the axis of the tensioning device and axially is arranged laterally offset to this and has a plurality of uniformly distributed second image acquisition units, which cover the weld seam without gaps, over the circumference of the weld seam and at a fixed radial distance from the latter.

For the purpose of handling and control, the proposed second arrangement is preferably further configured such that the second image capture device is connected to an image output unit, an image switch (a so-called video switcher) and a storage unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Two exemplary embodiments of an arrangement for carrying out the method according to the invention in its two advantageous variants are shown in the drawing and are described below. Show it 1 shows a central section through a so-called internal clamping device in connection with a first image capturing device according to the invention;

FIGS. 2 to 5 show the sequence of the steps from welding the root weld seam over its testing and assessment to the preparation of the next weld seam in connection with the welding on of another pipe part;

FIG. 6 shows a schematic illustration of a cross section through the tube in the region of its weld seam, a preferred first arrangement for carrying out the first method variant being shown;

FIG. 7 shows a schematic representation of a first device for image display (for example on a color monitor) in connection with a remote control for left and right rotation of the first arrangement according to the invention according to FIG. 6;

FIG. 8 shows a schematic illustration of a cross section through the tube in the region of its weld seam, a preferred second arrangement being provided with which the second method variant according to the invention can be carried out; 9 shows a schematic illustration of a view of the second arrangement according to FIG. 8, seen perpendicular to the tube axis, and

10 shows a schematic representation of a second device for image display in connection with an image switch (video switcher) for selecting the images of the weld seam captured with the second arrangement according to the invention according to FIG. 8.

REFERENCE SIGN LIST OF ABBREVIATIONS USED

1 internal clamping device

1a first tensioner head

1 a * first inner part

1aa * first outer part

1b second tensioner head 1 b ** second inner part q

1 bb ** second outer part

1c first drive rod

1c * first drive piston

1 d second drive rod

1d * second drive piston

1e first pressure medium hole

1f second pressure medium hole i g forming gas hole

1 h shaft

1 i supply pipe

1 k coupling device

2 first image capture device

2 * second image capture device

3 first image acquisition unit (can be driven all round)

3.1 to 3.r i second image capturing unit (fixedly arranged

4 support part

5 gears

5a driving wheel

5b driven wheel

5c gear motor

6 viewing windows

7 light source

8 camera (CCD color camera module with wide-angle optics)

^" 8.1 to 8.8 ι cameras (see above; fixed)

9a first limit switch

9b second limit switch

10 housing

11 image output unit (e.g. color monitor)

12 control unit

13 picture switches (video switcher)

14 storage unit

14a storage means

15 angular displacement measuring device

I anticlockwise r clockwise

A drive cylinder

B picture

D pressure medium

E * first pipe end of pipe part R _n

F * first pipe end of the pipe part R _{n + 1} c ** t _n +1 second pipe end of the pipe part R _{n + 1}

Cn + 2 second pipe end of the pipe part R _{n + 2}

Fi fault location

G forming gas

M center of picture

P position

Po reference or starting point

PFI fault location R pipeline

Rn pipe part n

Rπ + 1 pipeline part n + 1

Rn + 2 pipe part n + 2

S weld

S _A weld section

X optical axis α circumferential angle, measured from P ₀ φ picture angle φ ^* picture angle (related to pipe axis)

DETAILED DESCRIPTION

Pipe ends E _n * E _{n +} ι ^* * of two pipe parts R _n , R _{n + 1 to} be connected to one another via a weld seam S (FIG. 1) are mutually concentrically aligned and tensioned on the inside of the pipe ends using a so-called internal tensioning device 1. The axis of the internal clamping device 1 is aligned concentrically with the axis of the pipe ends E _n * E _{n +} ι **. The inner clamping device 1 consists, among other things, of a first clamping head 1a and a second clamping head 1b. The former consists of a wedge-shaped first inner part 1a * which expands in a radial direction in a first outer part 1aa *. The first outer part 1aa * is constructed from a plurality of segments distributed over the circumference, which are biased in the radial direction by means of two so-called worm springs, which are not specified and which surround the segments. The second tensioner head 1 b is constructed accordingly and has a second inner part 1 b ** and a second outer part 1 bb **.

The first tensioner head 1 a is connected to a first drive rod 1 c which engages the first inner part 1 a * and is driven by a first drive piston 1 c *. In the same way, the second inner part 1 b * ^{* of} the second tensioning head 1b is displaced in the axial direction via a second drive rod 1 d driven by a second drive piston 1d *. The first and the second drive pistons 1c * and 1d ^* are arranged in a drive cylinder A and can in each case on both sides with a pressure medium D, preferably compressed air, supplied via pressure medium bores 1e, 1f, under certain conditions (e.g. at Reduction of heat input) can also be applied with an incompressible pressure medium such as hydraulic oil. As a result, the two tension heads 1a, 1b can be controlled, each separately from one another, so that the pipeline end E _n * or E _{n + 1} ** assigned to the respective tension head 1a, 1 b is separated and independent of the other, tensioned and can be aligned concentrically to the internal clamping device 1.

The inner clamping device 1 described above initially allows the pipe end E _n * shown on the left in relation to the weld seam S to be clamped and aligned. The pipe end E _{n +} ι ^* * shown on the right can then be tensioned, the left-hand side being used on the right-hand side to form the weld seam S to be subsequently produced without a gap. A forming gas bore 1g is arranged in the first drive rod 1c and opens out in the area between the tensioning heads 1a, 1b into the interior space formed there by the two pipe ends E _n * and E _{n +} ι **. Forming gas G can be supplied during welding of the weld S via the forming gas bore 1g.

The drive housing A is connected on its end facing away from the tensioner heads 1 a, 1 b to a shaft 1h, through which the pressure medium bores 1e and 1f and the forming gas bore 1g are introduced into the inner clamping device 1. The shaft 1 h also carries on the outside a first or a second image capturing device 2 or 2 * according to the invention, each of which has a carrier part 4 in a housing 10 for receiving a gear 5, of which only the gear motor 5 c is shown (relates to the first image capturing device 2) , at least one viewing window 6, at least two light sources 7 and a first image acquisition unit 3 or a plurality of second image acquisition units 3.1 to 3.n. The gear motor 5c is connected directly or indirectly to the housing 10. The one or more viewing windows 6 and the light sources 7 are arranged in the latter. Seen in the circumferential direction, the light sources 7 can be offset on both sides of the respective viewing window 6 or else by 90 degrees against this arrangement direction, again on both sides of the viewing window 6 and be arranged on both sides of the weld seam S. The shaft 1h continues beyond the image capturing device 2, 2 * in a supply pipe 1 i.

The pipe ends E _n * and En ₊ ι ** of the pipe parts R _n and R _{π +} ι (FIG. 2), which are to be connected to one another via the weld seam S, are aligned concentrically with one another by means of the internal tensioning device 1, tensioned and largely freed from out-of-roundness. The arrangements according to the invention, the image capturing devices 2 and 2 *, are each preferably arranged on the supply side next to the drive cylinder A and are connected to the surroundings of the pipeline R to be produced via the supply pipe 1 i, in which all the energy and control lines are arranged. The supply pipe 1 i can be disconnected via a coupling device 1 k, so that the inner clamping device 1 with its drive cylinder A and the image capturing device 2, 2 * can be separated from the supply pipe 1 i brought in from the environment if necessary and then connected again ,

After completion of the root weld, the entire arrangement, consisting of the internal clamping device 1 with its drive cylinder A and the image capturing device 2, 2 *, is pushed away from the welded pipe part R _{n +} ι into the pipe part R _n so that the image capturing device 2, 2 * is positioned either directly under the weld seam S or slightly axially laterally offset below it, so that a complete image of the root of the weld seam S is possible. In this position, the weld seam S can now be checked, assessed, recorded and its image can be recorded on a suitable storage medium. The acquisition can be a static, pictorial acquisition of part of the weld S or else a film-like, continuously progressive acquisition of a section of the weld S, in each case until it is completely acquired (FIG. 3).

If the root is welded without defects, the weld S, which may have to be built up from several welding layers, is finished welded. If the assessment of the weld S shows that its root has defects, the latter must be re-welded. In both cases, that is to say if the root is faultless or defective, the entire arrangement, consisting of the internal clamping device 1, the drive cylinder A and the image capturing device 2, 2 *, is again brought into the welding position according to FIG. 2 (FIG. 4).

After completion of the weld S (Figure 5), the inner clamping device 1 and its drive cylinder A in connection with the image capture device 2, 2 * by means of the supply pipe 1 i so far in the direction of the free second pipe end E _{n +} ι ** until the coupling device 1 k is located outside the pipe part R _{n + 1} and is accessible. Now the next pipe part R _{n + 2} can be pushed over the latter at the separation point of the supply pipe 1 i created by the coupling device 1 k, and then, after connecting the ends of the supply pipe 1 i by means of the coupling device 1 k, with its second pipe end E _{n + 2} ^* * to be brought into a welding position according to FIG. 2. The process described above is now repeated until the entire pipeline R, consisting of a large number of pipeline parts, is completed.

FIG. 6 shows a first arrangement according to the invention, the first image acquisition device 2 for carrying out the first method variant according to the invention, namely the step-by-step or continuous visual acquisition of the weld S by means of a single first image acquisition unit 3. This first image acquisition unit 3, consisting for example of a camera 8 (e.g. CCD color camera module with wide-angle optics), two light sources 7 on both sides of the weld seam S, for example white light LED, a viewing window 6 and limit switches 9a, 9b for mutually peripheral limitation of a circumferential angle α, are fixedly mounted on the carrier part 4. The latter is rotatably mounted on the shaft 1 h, in the circumferential direction thereof, and is fixed non-displaceably in the axial direction thereof. The necessary rotational movement of the carrier part 4 is realized, for example, in such a way that a geared motor 5c in connection with a driving wheel 5a is fixedly arranged on it, the driving wheel 5a being a drives directly or indirectly firmly connected to the shaft 1 h driven wheel 5b. In this way, there is a planetary rotation of the carrier part 4 in connection with the first image acquisition unit 3 on the shaft 1 h and thus relative to the likewise fixed internal clamping device 1 in connection with the drive cylinder A. The viewing window 6 and the light sources 7 are arranged in the housing 10, which also accommodates the carrier part 4 and the first image acquisition unit 3.

With the illustrated first arrangement according to the invention (first image acquisition device 2), determinations about the nature, the completeness, the sagging of the roots and the presence of tarnishing colors can be made simply, quickly and inexpensively after welding in one work step. Handling does not require specially trained specialist personnel, but can be carried out by the welder. Equipping the arrangement with miniature optics with, for example, 6 mm focal length and, for example, a picture angle φ = 45 degrees in conjunction with light sources 7, for example special white-light LEDs, guarantees an optimal view of the weld seam S. The integrated gear 5 (5a, 5b , 5c) enables a rotation of the image acquisition unit 3 limited by limit switches 9a, 9b over a circumferential angle α (rotation angle) of, for example, α = 355 degrees.

For example, the first image acquisition unit 3 uses the image angle φ to acquire a weld seam section S _A. In this case, the optical axis X of the first image acquisition unit 3 is adjusted to an image center M of the weld seam section S _A which is represented as image B. The position of the first image capturing unit 3 shown also represents, for example, the reference point or starting point P _{0 of} the arrangement according to the invention at the beginning of the image capturing of the weld seam S. In the exemplary embodiment, the welding seam S is moved counterclockwise. The images B of the weld seam sections S _A can be generated step by step, one after the other, or they can be generated continuously and progressively. In any case, the sequence of images B results in a complete, consistent image of the weld seam S. With each image B generated in this way the respective position P of the image in relation to the defined reference or starting point Po is detected. For example, if the first image acquisition unit 3 is in a position in which its optical axis X passes through a position P, then the first image acquisition unit 3 has traveled the circumferential angle α from the reference or starting point Po. This circumferential angle α then also clearly defines the position P (P = f (α)).

The detection and determination of the circumferential angle α takes place via an angular path measuring device 15, which is designed, for example, in such a way that an unspecified wheel rolls on the inner wall of one of the tube ends E _n * or E _{n +} ι ** and detects this rolling movement and forms a Angle display (circumferential angle α) is processed. In addition, other angular path detection devices can also be integrated into the arrangement according to the invention (for example, pulse-wise control of the transmission 5 to complete a predetermined circumferential angle α).

If, for example, the weld seam S produced has an error point Fj, then according to the invention the first image acquisition unit 3 is moved so far that the error point Fj is shown in the center M of the image B. In this position of the first image capturing unit 3, the image center M of the image B, viewed in the circumferential direction and in relation to the reference or starting point P ₀ , has a position P, which is now defined as the error location position P _Fl -. This fault location position P _R is characterized by a designated circumferential angle α _R (P = P _R = f (α)). The positioning of a welding tool can be controlled with the aforementioned fault location position P _Fi , so that the fault location Fj can be deliberately overwelded and thus eliminated.

The step-by-step or continuously acquired image sequence is made visible via an image output unit 11 (for example a color monitor), with left or right rotation I or r of the first image acquisition unit 3 being triggered by a control unit 12. The image documents are read out and stored in a storage unit 14 on a suitable storage means 14a (FIG. 7). The second arrangement according to the invention, the second image capturing device 2 *, which can be used whenever the pipeline R to be welded has a minimum diameter, is shown in FIG. 8. The second image capturing device 2 * is fixed with respect to the weld seam S and consists of a number n of second image capturing units 3. In the present case there are eight (3.1 to 3.8), each capturing at least one sector of the weld seam S with cameras 8.1 to 8.8, which then has an image angle φ * = 45 degrees, based on the pipe axis. The second image capturing units 3.1 to 3.8 are arranged on the carrier part 4 already described in connection with FIG. 6. In the housing 10, also mentioned above, eight viewing windows 6 are now arranged in connection with light sources 7 between and / or on both sides of the viewing windows 6. The overall arrangement is now fixed immovably on the shaft 1h both in the axial and in the circumferential direction. A rotation is no longer necessary, since the n = 8 second image acquisition units 3.1 to 3.8 provided capture the weld seam S simultaneously and completely over a wrap angle of α = 360 degrees.

An error point Fj can in any case be assigned to one of the weld seam sections S _A (for example S _{A of} the image acquisition unit 3.6) and the position indicated for the latter (position P of the image acquisition unit 3.6) is defined as the error location position P _R in question (P (α) = P _R ).

Figure 9 illustrates the above-mentioned situation in the schematically illustrated view of the arrangement. The individual images B of the weld seam sections S _A are output via the image output unit 11 and made visible (FIG. 10). All images B of the n = 8 second image acquisition units 3.1 to 3.8 are fed into an image switch 13 (a so-called video switcher), and they can be opened from here simultaneously (for example on the image output unit 11 divided into eight monitor areas) or in succession of the undivided image output unit 11 are output and displayed. In addition, there is the possibility of individually selecting each receptacle in order to review and assess a specific welding section S _A again. The possibility is further provided that the image changeover switch 13 automatically switches from one image to the other so that all eight images of the weld seam S appear in succession on the image output unit 11. The time intervals for the sequence of the individual images can optionally be preset on the image selector 13 in the context of an automatically operating arrangement. The image documents are read out and stored via the storage unit 14 on a suitable storage means 14a.

Claims

claims

1. Procedure for the visual inspection and assessment of circular welds in pipelines,

• in which the pipe ends to be connected (E _n *, E _{π + 1} **) of two pipe parts (R _π , R _{n + 1} ) are mutually concentrically aligned and tensioned by a tensioning device (1) acting on the inside of the pipe ends and the axis of the tensioning device (1) is aligned concentrically with the axis of the pipe ends,

In which, after welding the root of a weld (S), the tensioning device (1) is loosened and moved in the direction of the tube axis in such a way that an image acquisition device (2; 2 *) arranged axially laterally on the tensioning device (1) for image acquisition, Transfer and display of the weld seam (S) positioned in the reproducible area of the weld seam • in which the weld seam (S), viewed in the circumferential direction, is imaged in weld seam sections (S _A ),

• in which each image (B) of a weld seam section (S _A ) generated in this way is recorded in its respective position (P), based on a defined reference point or starting point (P ₀ ), and • in which the image (B) and its Position (P) displayed and / or read out and saved.

2. The method according to claim 1, characterized in that an image center (M) of the respective image (B), seen in the circumferential direction and based on the reference or starting point (P ₀ ), is used to generate the position (P).

3. The method according to claim 1 or 2, characterized in that the images (B) of the weld seam sections (S _A ) are generated step by step, one after the other, and that the sequence of images (B) results in a complete, consistent image of the weld seam (S) ,

4. The method according to claim 1 or 2, characterized in that the images (B) of the weld sections (S _A ) are generated continuously, progressively, and that the sequence of images (B) results in a seamless, consistent image of the weld (S) ,

5. The method according to any one of claims 1 to 4, characterized in that an error location (Fj) in the center of the image (M) of the image (B) and that the position (P) shown for this image center (M) as the location of the error location (P _Fi ) is defined.

6. The method according to claim 1 or 2, characterized in that the images (B) of the weld seam sections (S _A ) are generated simultaneously, and that the combination of the images (B) results in a complete, consistent image of the weld seam (S) ,

7. The method according to claim 6, characterized in that a fault location (Fj) is assigned to a suitable weld section (S _A ), and that the position (P) shown for the latter is defined as a fault location position (P _Fi ).

8. The method according to claim 5 or 7, characterized in that the fault location (P _Fi ) for positioning a welding tool for producing the weld seam (S) is used.

9. The method according to any one of claims 1 to 8, characterized in that the imaging of the weld seam (S) is controlled manually.

10. The method according to any one of claims 1 to 8, characterized in that the imaging of the weld seam (S) is controlled automatically.

11. Arrangement for the visual inspection and assessment of circular welds in pipelines, «with a tensioning device (1) that the to be connected

Pipe ends (E _n ^* , E _n + ι ^** ) of two pipe parts (R _π , R _{π + 1} ) each align and tension each other concentrically on the inside of the pipe ends and which is concentric to the axis of the pipe ends, «with a first image capture device (2) for image acquisition,

Transmission and representation of the weld seam (S), the first image capturing device (2) being arranged coaxially to the axis of the tensioning device (1) and axially laterally offset from it and circumferentially in the circumferential direction of the weld seam (S) and at a fixed radial distance from it drivable first image acquisition unit (3), and

• With an angular path measuring device (15), which detects a circumferential angle (α), which the first image acquisition unit (3) has covered based on a defined reference or starting point (P ₀ ).

12. The arrangement according to claim 11, characterized in that the first

Image acquisition device (2) is connected to an image output unit (11), a control unit (12) and a storage unit (14).

13. Apparatus for the visual inspection and assessment of circular welds in pipelines,

• With a tensioning device (1) which concentrically aligns and clamps the pipe ends (E _n ^* , E _n + ι ^** ) of two pipe parts (R _n , R _n + ι) to each other on the inside of the pipe ends and which aligns itself concentrically to the axis of the pipe ends,

• with a second image acquisition device (2 *) for image acquisition, transmission and display of the weld seam (S), the second image acquisition device (2 ^* ) being arranged coaxially to the axis of the tensioning device (1) and axially laterally offset from it and over the circumference the weld seam (S) and at a fixed radial distance from it has a plurality of evenly distributed second image capturing units (3.1, 3.2, ... 3.n) which capture the weld seam without gaps.

14. Arrangement according to claim 13, characterized in that the second image capture device (2 ^* ) with an image output unit (11), an image switch (13) and a storage unit (14) is connected.