Sleeve weld inspection

Abstract

To provide a method and a device capable of ultrasonic testing of pipes welded using an electrically welded sleeve.SOLUTION: A method and device for ultrasonic testing of a weld of an electrically welded sleeve for plastic pipes 11 include the steps of: attaching a testing device 1 on an outer peripheral surface of the welded plastic pipe, which comprises an attaching member 2 extending over the whole circumference, a holder 3 preferably having a support, a carrier 8, and a gripper, and a guide member 5 including a cut-out portion; feeding a liquid, preferably water, into the cut-out portion of the guide member. In the method and the device, the cut-out portion provided in the guide member is fully filled with the liquid, and a constant liquid column is maintained in the guide member during the ultrasonic testing to transmit ultrasound.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention provides a method and apparatus for ultrasonically inspecting welds in electric weld sleeves for plastic pipes, comprising the following steps and components: The method includes the steps of: attaching an inspection device to an outer peripheral surface of a welded plastic pipe, the inspection device having a mounting member extending around the entire circumference, a holder, and a guide member; providing a liquid to the cutout of the guide member; The present invention relates to a method and apparatus having [Background technology]

[0002] Non-destructive testing of test objects by means of ultrasound is a conventional technique and is used in many fields, for example in aircraft construction. This method is mainly applied to metallic materials, since they have good acoustic conductivity. Ultrasonic testing is preferably used to detect internal and external defects that would not be visible without destroying the test object.

[0003] CN 110031549 discloses an apparatus for inspecting the weld seams of pipes that are butt-welded together. This embodiment has the disadvantage that it is not suitable for ultrasonic inspection of electric welded sleeves. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the invention is to propose a method and an associated device which make it possible to carry out ultrasonic inspection of pipes welded with electric welding sleeves. [Means for solving the problem]

[0005] This problem is solved according to the invention in that the guide element has a cutout extending consistently through the central region, a compressible retention element is arranged on the underside of the guide element, which serves to retain the liquid supplied to the guide element, the cutout in the guide element being completely filled with liquid, and a constant liquid column is maintained in the guide element during ultrasonic testing in order to transmit ultrasound.

[0006] During the test process, it is advantageous if liquid is constantly supplied into the guide element: although during the test there is no absolute tightness between the guide element and the electric welding sleeve which supports it and around which it rotates, there is nevertheless necessarily a pre-existing liquid column in the cutout of the guide element throughout the entire test process, by means of which the ultrasonic waves can be guided to the electric welding sleeve or to the weld point.

[0007] To perform an inspection of the weld of the electric weld sleeve on the pipe, the inspection device is preferably rotated around the sleeve and thus the welded pipe, so that such an inspection can be performed on an electric weld sleeve that is already installed in a pipe system.

[0008] Preferably, the inspection device rotates at least 360°. This ensures a complete inspection of the weld.

[0009] The inspection device according to the invention for ultrasonically inspecting the welds of electric welding sleeves for plastic pipes has a circumferentially extending mounting element, a holder and a guide element, the guide element serving to guide ultrasonic waves to the weld and the holder being a connecting means between the circumferentially extending mounting element and the guide element. The guide element has a cutout that runs all the way through in the central area, and a compressible retention element is arranged on the underside of the guide element, which retention element serves to retain the liquid supplied in the guide element. The guide element is rotated around the outer circumferential surface of the electric welding sleeve by the inspection device in order to inspect the entire weld seam. Since liquid is present in the cutout of the guide element, which is always open and thus allows the liquid to come into contact with the outer circumferential surface of the electric welding sleeve, a loss of liquid occurs due to the rotation. An absolute tightness between the guide element and the outer circumferential surface of the electric welding sleeve is almost impossible to achieve due to the unevenness of the outer circumferential surface. However, the loss of liquid is minimized by the retention element in order to maintain a constant liquid column in the cutout.

[0010] It is advantageous if the surface of the continuous cutout is made of polyamide (PA). This means that the liquid column is surrounded by polyamide. The guide element can be manufactured from polyamide, but it is also possible that the guide element is made of another material, in which case an insert made of polyamide is inserted into the guide element, which forms the continuous cutout. Preferably, the polyamide in the form of an edge protrudes into the retention element or the retention element surrounds a protruding narrow edge, whereby the edge is supported by the sleeve and the retention element mainly bridges the irregularities. Due to the uniform surface made of polyamide surrounding the liquid, the quality of the ultrasonic signal is very good due to the constant and identical sound wave properties.

[0011] Preferably, the retention member is made of a sponge-like material, and particularly preferably is a sponge, which makes it possible to compensate for unevenness on the circumferential surface of the electric welding sleeve. In other words, the retention member is supported on the grooves and ridges on the circumferential surface and retains the liquid in the cutout, so that liquid is constantly supplied to the guide member, thereby compensating for the liquid that escapes and maintaining the liquid column despite the retention member being provided.

[0012] The circumferential attachment element is advantageously designed as a chain, with each standard chain element preferably having a hook and a hook receptacle which engages with one another by hooking. The design of the attachment element as a chain allows the attachment element to be fastened or wrapped around an existing pipe and the chain to be optionally lengthened or shortened. Due to the hooks and hook receptacles, the standard chain elements can be connected to one another only by engaging with one another.

[0013] An advantageous configuration of the testing device according to the invention consists in that the holder has a support, which is formed as a chain element and is integrated into the chain by hook engagement. The support preferably has an angle sensor for monitoring the rotation angle of the testing device. It has also proven advantageous if anti-slip elements are arranged on the holder, which prevents the testing device from slipping off in a vertically installed pipe. The anti-slip elements are preferably arranged as disks on the hinges of the holder and come into contact with the circumferential surface of the pipe.

[0014] Preferably, a gripper is arranged on the holder, with the guide member attached to the gripper, and preferably the gripper has a mounting post to which the guide member is attached and appropriately positioned, since the inspection device can be used for a number of different electric welding sleeves and a number of different diameters.

[0015] The holder preferably has a guide in which the gripper is arranged, via which the gripper can be adjusted parallel to the pipe axis. In order to position the guide at the height of the weld seam (which is not visible since it occurs on the sleeve between the sleeve and the pipe circumference), the guide preferably has a stop which rests on the sleeve, so that the guide is correctly positioned.

[0016] All configuration possibilities can be freely combined with one another and also the features mentioned with respect to the method can be combined with the inspection device and vice versa.

[0017] An embodiment of the present invention will be described with reference to the drawings, although the present invention is not limited to this embodiment. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a three-dimensional view of an installed inspection device according to the invention; [Diagram 2] 1 is a three-dimensional view showing an inspection device according to the present invention; [Diagram 3] 1 is a three-dimensional view showing an inspection device according to the present invention; [Figure 4] FIG. 2 shows a three-dimensional view of a holder with guiding members of an inspection device attached; [Diagram 5] FIG. 13 is a three-dimensional view showing a holder equipped with a guide member. [Figure 6] FIG. [Figure 7] FIG. 4 is a longitudinal cross-sectional view of a guide member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] In the drawing shown in FIG. 1, an inspection device 1 according to the invention is shown for ultrasonically inspecting welds of electric welding sleeves 10 for plastic pipes 11. The inspection device 1 has a circumferentially extending mounting element 2, which is mounted around the plastic pipe 11 for inspection. The mounting element 2 is preferably designed as a chain and has a standard chain element 12. The chain element 12 preferably has hooks 13 and hook receivers 14, so that the elements 12 are connected to one another only by hook engagement, without any need for laborious tightening or loosening of screw fastenings. This has the advantage that the chain 2 can be quickly installed and adapted to its length. The inspection device 1 according to the invention has a holder 3, which is arranged on the circumferentially extending mounting element 2. The holder 3 preferably has a support 7, which is designed as a chain element and can therefore be easily adapted or hook-engaged to the chain 2. An angle sensor 15 is preferably also arranged on the holder 3, which detects the angle at which the inspection is performed and also ensures that a 360° inspection is performed. The holder 3 preferably has a carrier 8, which adjusts the adjustment means of the crimping pressure of the guide element 4 against the circumference of the electric welding sleeve 10 via an adjustment unit 16 and also serves as an auxiliary means for liquid control and supply, since hoses and valves (not shown) for supplying liquid to the guide element 4 are attached to the carrier 8. The guide element 4 arranged on the inspection device 1 serves for the transmission of ultrasonic waves to the electric welding sleeve 10 or for welding at the electric welding sleeve 10. The guide element 4 is attached to the holder 3 and is adjustable thereby. An ultrasonic inspection device (not visible) is attached to the upper side of the guide element 4, so that ultrasonic waves run approximately perpendicularly to the circumference of the electric welding sleeve 10 through a cutout 5 (better visible in FIG. 6) in the guide element 4, which is filled with liquid. A retention member 6 is disposed on the lower surface of the guide member 4, and the retention member 6 retains the liquid for ultrasonic transmission within the cutout portion 5, thereby maintaining the liquid column.Furthermore, liquid is supplied into the guide element 4 via a supply 17 in order to compensate for any loss of liquid during the test.

[0020] The guide element 4 is preferably adjustably arranged on a gripper 9. The gripper is advantageously arranged on a guide 18, which runs parallel to the tube axis and is preferably connected to the carrier 8. A number of anti-slip elements 19 are preferably arranged on the holder 3, which prevent the inspection device 1 according to the invention from slipping down in a vertically running line.

[0021] The guide element 4 has a stop 20 for accurate positioning on the electric welding sleeve 10, so that the guide element 4 is positioned directly above the weld seam.

[0022] In Fig. 7 the guide element 4 is shown in a longitudinal section. The surface 21 of the cutout 5 consists of polyamide and is formed in one piece with the guide element 4. Alternatively, the surface 21 can be formed by an insert which is inserted into the guide element 4, so that the guide element does not necessarily have to have the same material. It is advantageous if the edge 22 protrudes into the retention element 6. This ensures that the liquid column is surrounded only by the PA, which ensures a good signal quality. [Explanation of symbols]

[0023] 1. Inspection equipment 2. Mounting members extending all around 3 Holder 4 Guide member 5 Cutout guide member 6 Retention material 7 Support part 8. Career 9 Gripper 10 Electric welding sleeve 11 Plastic pipes 12 Standard chain components 13. Hook 14 Hook receiving part 15 Angle Sensor 16 Adjustment unit 17 Supply section 18 Guide 19 Anti-slip material 20 Stopper 21 Surface of cutout PA 22 Edge

Claims

1. A method for ultrasonically inspecting a weld of an electric weld sleeve (10) for a plastic pipe (11), comprising the following steps: Attaching an inspection device (1) to the outer peripheral surface of the welded plastic pipe (11), the inspection device (1) having a mounting member (2) extending around the entire circumference, a holder (3) having a support portion (7), a carrier (8) and a gripper (9), a guide member (4) having a cutout portion (5) extending consistently through a central region, and a compressible retention member (6) arranged on the underside of the guide member (4); supplying a liquid to said cutout (5) of said guide member (4); In a method having the following structure:

2. A method according to claim 1, further comprising: completely filling said cutout (5) in said guide (4) with said liquid and maintaining a constant liquid column in said guide (4) during ultrasonic testing in order to transmit ultrasonic waves.

2. 2. The method according to claim 1, further comprising the step of constantly supplying liquid into said guide element (4) during the testing process.

3. 3. The method according to claim 1 or 2, characterized in that the inspection device (1) for inspecting the weld is rotated around the plastic pipe (11) and the electric welding sleeve (10).

4. 4. The method according to claim 1, wherein the inspection device (1) rotates at least 360[deg.].

5. An inspection device (1) for ultrasonically inspecting welds of electric welding sleeves (10) for plastic pipes (11), comprising a circumferentially extending mounting element (2), a holder (3) and a guide element (4), the guide element (4) serving to guide ultrasonic waves to the weld, the holder (3) being a connection means between the circumferentially extending mounting element (2) and the guide element (4), The guide member (4) has a cutout (5) extending consistently through a central region, and a compressible retention member (6) is arranged on the underside of the guide member (4), the retention member (6) serving to retain liquid that is supplied into the guide member (4), completely fills the cutout (5), and maintains a constant liquid column within the guide member (4) during ultrasonic testing.

6. 6. The inspection device (1) according to claim 5, wherein the surface of the continuous cutout (5) consists of polyamide (PA).

7. 7. The testing device (1) according to claim 5 or 6, wherein the retention member (6) is made of a spongy material.

8. 8. The inspection device (1) according to claim 5, wherein the circumferentially extending attachment members are formed as a chain, each standard chain member having a hook and a hook receiving portion, which are in hook engagement with one another.

9. 9. The inspection device (1) according to claim 8, wherein the holder (3) has a support (7), which is formed as a chain member and which is integrated into the chain by hook engagement.

10. 10. The inspection device (1) according to any one of claims 5 to 9, characterized in that the holder (3) comprises a gripper (9), which supports the guide element (4).

11. 11. Inspection device (1) according to claim 10, characterized in that the gripper (9) is positionable via a guide.

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