Inspection sleeve welding

Abstract

A method and device for ultrasonic testing of the weld of an arc welding sleeve (10), the arc welding sleeve (10) being used for a plastic pipe (11), the method comprising the following steps: • fastening a testing device (1) to the outer contour of the welded plastic pipe (11), the testing device comprising a circumferential fastening element (2) and a retaining member (3) and a coupling element, the retaining member (3) preferably comprising a support member (7), a bracket (8) and a clamping member (9), the coupling element having a recess, • injecting a liquid into the recess (5) of the coupling element (4), the liquid being preferably water, wherein the recess (5) in the coupling element (4) is completely filled with the liquid and during the ultrasonic testing, a constant liquid column is maintained in the coupling element (4) to transmit ultrasonic waves.

Description

Technical Field

[0001] The present invention relates to a method and a device for ultrasonic testing of a weld of an arc welding sleeve for a plastic pipe, the method and the device having the following steps and components:

[0002] • fastening the detection device to the outer contour of the welded plastic pipe, the detection device comprising: a circumferential fastening element, a retaining element and a coupling element,

[0003] • Feed the liquid into the recess of the coupling element. Background Art

[0004] Non-destructive testing of test objects by means of ultrasound is known technology and is used in many fields, for example in the field of aircraft construction.

[0005] This method is mainly used for metallic materials because they have good acoustic conductivity.

[0006] Ultrasonic testing is intended to find internal and external defects that would not be detectable without damaging the object being tested.

[0007] CN 110031549 A1 discloses a device for inspecting weld seams of pipes butt-welded to each other.

[0008] A disadvantage of this embodiment is that it is not suitable for ultrasonic testing of arc welding sleeves. Summary of the invention

[0009] The object of the present invention is to provide a method and an associated device making it possible to carry out ultrasonic testing of pipes welded by means of an arc welding sleeve.

[0010] This object is achieved according to the invention in that the coupling element comprises a continuous recess in a central area and a compressible retaining element is arranged on the underside of said coupling element, the retaining element being used to retain the liquid injected into the coupling element, the recess in the coupling element being completely filled with liquid and a constant liquid column being maintained in the coupling element during ultrasonic testing in order to transmit ultrasonic waves.

[0011] Advantageously, during the test process, liquid is continuously injected into the coupling element. Since there is no absolute seal between the coupling element and the arc welding sleeve during the test, the coupling element is supported on the arc welding sleeve and the coupling element rotates on the circumference of the arc welding sleeve, nevertheless, throughout the entire test process, a liquid column must be present in the recess of the coupling element in order to couple the ultrasound into the arc welding sleeve or into the welding location.

[0012] In order to carry out the inspection of the welding of the arc welding sleeve to the pipe, the inspection device is preferably rotated around the sleeve and the pipe welded to the sleeve. In this way, such inspection can be carried out on the arc welding sleeve which has been installed in the pipeline system.

[0013] Preferably, the rotation of the inspection device comprises at least 360°. This ensures a complete inspection of the weld.

[0014] The detection device according to the invention is used for ultrasonic testing of the weld of an arc welding sleeve for plastic pipes, the detection device comprising a circumferential fastening element, a retaining element and a coupling element, the coupling element being used to couple ultrasound into the weld, the retaining element being a connecting piece between the circumferential fastening element and the coupling element. The coupling element comprises a continuous recess in a central region, and a compressible retaining element is arranged on the lower side of the coupling element, the retaining element being used to retain the liquid injected into the coupling element. The coupling element is rotated around the outer contour of the arc welding sleeve by means of the detection device in order to detect the entire weld. Since there is liquid in the recess of the coupling element, this recess is completely open, and therefore the liquid is in contact with the side surface of the arc welding sleeve, liquid losses occur due to the rotation. Due to the unevenness on the outer contour, an absolute seal between the coupling element and the outer contour of the arc welding sleeve is hardly achievable. Nevertheless, in order to maintain a constant liquid column in the recess, the liquid losses are minimized by means of the retaining element.

[0015] It is advantageous that the surface of the continuous recess is made of polyamide (PA). This means that the liquid column is surrounded by polyamide. The coupling element can also be made of polyamide, although it is also possible that the coupling element is formed of a different material and then the polyamide insert forming the continuous recess is introduced into the coupling element. Preferably, the polyamide extends into the retaining element in the form of an edge, or the retaining element surrounds a narrow protruding edge, so that this edge bears on the sleeve and the retaining element mostly bridges unevenness. With the same polyamide surface surrounding the liquid, the signal quality of the ultrasound is very good due to the consistent sound properties.

[0016] Preferably, the retaining element is made of a spongy material, particularly preferably of a sponge. In this way, it is possible to compensate for unevenness in the side surface of the arc welding sleeve. The retaining element thus lies in the indented grooves and on the protrusions on the side surface and retains the liquid in the recess, and despite the retaining element, the liquid is continuously injected into the coupling element in order to compensate for liquid leakage and in order to maintain the liquid column.

[0017] It is advantageous that the circumferential fastening element is configured as a chain, the standard chain links preferably comprising hooks and hook recesses and hooked to each other. By virtue of the fact that the fastening element is configured as a chain, the fastening element can be mounted on or placed around an existing pipe and closed, and furthermore it is extendable and shortenable as desired. By virtue of the hooks and hook recesses, the standard chain links can be connected to each other simply by hooking into each other.

[0018] An advantageous configuration of the detection device according to the invention comprises a holder comprising a support configured as a chain link and integrated into the chain by hooking. The support preferably comprises an angle encoder which monitors the angle of rotation of the detection device. It has furthermore been found to be advantageous to arrange anti-slip elements on the holder so that in the case of a vertically placed pipe the detection device is prevented from slipping. Preferably, these are arranged as discs at the articulation of the holder and come into contact with the side surface of the pipe.

[0019] Preferably, a clamp is arranged on the holder, to which the coupling element is fastened. Preferably, since the detection device can be used for different arc welding sleeves and different diameters, the clamp comprises fastening structs, to which the coupling element is fastened and positioned accordingly.

[0020] Preferably, the holder comprises a guide on which the clamp is arranged. By means of this guide, the clamp can be adjusted parallel to the pipe axis. In order to position the coupling element at the level of the weld seam (which is not visible since it is formed inside the sleeve between the nut and the outer contour of the pipe), the coupling element preferably comprises a stopper which rests on the sleeve, as a result of which the coupling element is correctly positioned.

[0021] All configuration possibilities can be freely combined with one another, and all features mentioned in connection with the method can be combined with the detection device and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Exemplary embodiments of the invention will be described with the aid of the drawings, without the invention being restricted to the merely exemplary embodiments.

[0023] Figure 1 A three-dimensional view showing a fastening detection device according to the invention,

[0024] Figure 2 A three-dimensional view showing a detection device according to the invention,

[0025] Figure 3 A three-dimensional view showing a detection device according to the invention,

[0026] Figure 4 A three-dimensional view of a holder with a coupling element showing a fastened test device,

[0027] Figure 5 A three-dimensional view showing a holder with a coupling element,

[0028] Figure 6 A three-dimensional view showing the coupling element, and

[0029] Figure 7 A longitudinal section through the coupling element is shown. DETAILED DESCRIPTION

[0030] exist Figure 1The figure presented shows a detection device 1 according to the invention for ultrasonic testing of welds of an arc welding sleeve 10 for plastic pipes 11. The detection device 1 comprises a circumferential fastening element 2, which is placed around the plastic pipe 11 for testing. Preferably, the fastening device 2 is configured as a chain and comprises standard chain links 12. The chain links 12 preferably comprise hooks 13 and hook recesses 14, as a result of which the chain links 12 are connected to each other only by hooking in and without screws that have to be troublesomely fastened or loosened. This has the advantage that the chain 2 can be quickly mounted or adapted in length. The detection device 1 according to the invention comprises a holder 3, which is arranged on the circumferential fastening element 2. The holder 3 preferably comprises a support 7, which is formed as a chain link and can therefore be easily assembled or hooked into the chain 2. An angle encoder 15, which records the angle through which the detection takes place and also ensures that a 360° detection is carried out, is also preferably arranged on the holder 3. The holder 3 preferably comprises a bracket 8, which adjusts the setting of the application pressure of the coupling element 4 on the side surface of the arc welding sleeve 10 by means of an adjustment unit 16 and also serves as a support for the regulation and injection of liquid through a tube and a valve (not shown) fastened to the tube, which injects liquid into the coupling element 4. The coupling element 4 arranged on the detection device 1 is used to transmit ultrasonic waves into the arc welding sleeve 10, or to the weld in the arc welding sleeve 10. The coupling element 4 is fastened to the holder 3 and is thereby adjustable. An ultrasonic detection device (not visible) is applied to the upper side of the coupling element 4, as a result of which the ultrasonic waves are aligned approximately vertically onto the side surface of the arc welding sleeve 10 and pass through the recess 5 in the coupling element 4, which recess 5 is located at Figure 6 It can be clearly seen that this recess 5 is filled with liquid. A holding element 6 is arranged on the lower side of the coupling element 4, which holds the liquid in order to maintain a liquid column, which is used to transmit the ultrasound in the recess 5. In addition, liquid is injected into the coupling element 4 through the injection port 17 in order to compensate for the loss of liquid during detection.

[0031] The coupling element 4 is preferably adjustably arranged on the clamp 9. It is advantageous for the clamp to be arranged on a guide 18 which extends parallel to the axis of the pipe and is preferably connected to the bracket 8. Anti-slip elements 19 are preferably arranged on the holder 3, which, in the case of vertically extending pipes, prevent the detection device 1 according to the invention from sliding down.

[0032] The coupling element 4 comprises a stop 20 for correct positioning on the arc welding sleeve 10 so that it is positioned directly above the weld seam.

[0033] Figure 7The coupling element 4 is shown in longitudinal section. The surface 21 of the recess 5 is made of polyamide, the coupling element 4 being shown here as a single piece. Alternatively, the surface 21 can also be formed by an insert which is fitted into the coupling element 4, as a result of which the coupling element does not need to consist of the same material. It is advantageous that the edge 22 protrudes into the retaining element 6. The liquid column is thus surrounded only by the PA, which ensures a good signal quality.

[0034] Reference numerals list

[0035] 1. Testing equipment

[0036] 2 Circumferential fastening elements

[0037] 3. Retaining parts

[0038] 4 Coupling elements

[0039] 5 Recess of coupling element

[0040] 6. Retaining element

[0041] 7 Support

[0042] 8 Bracket

[0043] 9 Clamping parts

[0044] 10 Arc welding sleeve

[0045] 11 Plastic pipe

[0046] 12 standard links

[0047] 13 Hook

[0048] 14 Hook recess

[0049] 15 Angle encoder

[0050] 16 Adjustment unit

[0051] 17 Inlet

[0052] 18 Guide

[0053] 19 Anti-slip elements

[0054] 20 Stopper

[0055] 21 PA surface of concave part

[0056] 22 Edge

Claims

1. A method for ultrasonic testing of the weld of an arc welding sleeve (10) for a plastic pipe (11), the method comprising the following steps: Fastening a detection device (1) on the outer contour of the welded plastic pipe (11), the detection device (1) comprising a circumferential fastening element (2) and a holder (3) and a coupling element with a recess, injecting liquid into the recess (5) of the coupling element (4), It is characterized in that The recess (5) in the coupling element (4) is completely filled with the liquid and during the ultrasonic testing, a constant liquid column is maintained in the coupling element (4) to transmit ultrasonic waves, wherein the testing device (1) rotates around the plastic pipe (11) and the arc welding sleeve (10) to test the weld.

2. The method according to claim 1, characterized in that During the detection process, liquid is continuously injected into the coupling element (4).

3. The method according to claim 1 or 2, characterized in that: The rotation of the detection device (1) includes at least 360°.

4. The method according to claim 1, characterized in that: The retaining member (3) comprises a supporting member (7), a bracket (8) and a clamping member (9).

5. The method according to claim 1, characterized in that The liquid is water.

6. A detection device (1) for ultrasonic testing of a weld of an arc welding sleeve (10), the arc welding sleeve (10) being used for a plastic pipe (11), the detection device (1) comprising a circumferential fastening element (2), a retaining element (3) and a coupling element (4), the coupling element (4) being used to couple ultrasound into the weld, the retaining element (3) being a connecting element between the circumferential fastening element (2) and the coupling element (4), characterized in that The coupling element (4) comprises a continuous recess (5) in a central region, and a compressible retaining element (6) is arranged on the underside of the coupling element (4), the retaining element (6) being used to retain liquid injected into the coupling element (4).

7. The detection device (1) according to claim 6, characterized in that The surface of the continuous recess (5) is made of polyamide (PA).

8. The detection device (1) according to claim 6 or 7, characterized in that The retaining element (6) comprises a water-absorbing material.

9. The detection device (1) according to claim 6 or 7, characterized in that The circumferential fastening element is configured as a chain.

10. The detection device (1) according to claim 9, characterized in that The holder (3) comprises a support (7) which is configured as a chain link and is integrated into the chain by hooking.

11. The detection device (1) according to claim 6 or 7, characterized in that: The retaining member (3) comprises a clamping member (9) which receives the coupling element (4).

12. The detection device (1) according to claim 11, characterized in that The clamping element (9) can be positioned by means of a guide element.

13. The detection device (1) according to claim 9, characterized in that Standard links include hooks and hook recesses and are hooked to each other.

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