Pipeline butt weld inner wall exposure device and detection process

Abstract

The present application relates to an exposure device for the inner wall of a butt weld of a pipeline and a detection process thereof, which relates to the field of weld detection technology. The device comprises a gamma-ray flaw detector, an exposure head, and a wire connecting the two. The device also comprises an arc tube, wherein the outer wall of a second straight tube is rotatably connected to a plurality of support rods, the plurality of support rods being evenly distributed along the circumference of the second straight tube. A torsion spring is provided between the support rods and the second straight tube, the elastic force of the torsion spring driving the support rods to rotate away from the second straight tube. A pull wire is fixed to the inner wall of the support rod, which passes through the interior of the arc tube. The outer wall of the second straight tube is provided with a groove for the support rods to enter. The arc tube in the detection device can be inserted into a test tube and removed in the opposite direction. The support rods and pull wires ensure that the exposure head is positioned on the central axis of the test tube, thereby eliminating the need for a positioning bracket within the test tube. The device and process are suitable for on-site post-weld inspection operations, without the need to dismantle the tube and without leaving objects in the test tube. The device and process are also suitable for test tubes of different diameters, thus having a wide range of applicability.

Description

Technical Field

[0001] The present application relates to the technical field of weld detection, and in particular to a pipeline butt weld inner wall exposure device and a detection process thereof. Background Art

[0002] Radiographic testing is an important means of inspecting the welding quality of thick-walled pipes. For this type of inspection object, gamma rays are superior to X-ray double-wall single-shadow radiography. Gamma ray sources have the advantages of large radiographic thickness, strong penetration ability, and low equipment failure rate. Gamma source double-wall single-shadow radiography is now widely used for inspection.

[0003] The existing invention patent application with publication number CN104569007A discloses a device for exposing the center of a thick-walled pipe butt weld, including an arc tube for guiding the source tube of a gamma-ray flaw detector. The arc tube is composed of a first straight tube, a curved tube, and a second straight tube connected in sequence. The free end of the first straight tube is located at the geometric center of the butt weld of the thick-walled pipe, and the free end of the second straight tube passes through a preset through hole of the thick-walled pipe. Through the setting of the arc tube, the gamma source can be effectively transported to the position of the center of the weld for exposure, which can greatly shorten the exposure time and improve the gamma-ray operation efficiency and detection sensitivity; the first straight tube and the second straight tube of the arc tube are both telescopic tubes, which have a wider range of uses; the preset through hole is the existing instrument hole or tee port on the thick-walled pipe, and no additional hole is required.

[0004] Regarding the aforementioned related technologies, the inventors believe that the positioning plate, first straight pipe, and other structures are difficult to remove from the pipeline. Therefore, this solution is suitable for laboratory use and cannot be adapted for on-site construction. After on-site welding, the pipeline is already installed and will not be intentionally removed. Therefore, this solution has the problem of being unable to remove the positioning plate, first straight pipe, and other structures, making it unsuitable for on-site operations and requiring improvement. Summary of the Invention

[0005] The present application provides a pipeline butt weld inner wall exposure device and its detection process. The detection device can be inserted into the pipeline and taken out in the reverse direction, and can be adapted to on-site post-weld detection operations without disassembling the pipe.

[0006] This application provides a device for exposing the inner wall of a pipe butt weld, which adopts the following technical solution:

[0007] A device for exposing the inner wall of a pipe butt weld includes a gamma-ray flaw detector, an exposure head, and a wire connecting the two, and also includes an arc tube, wherein the arc tube includes a first straight tube, a curved tube, and a second straight tube connected in sequence, the first straight tube and the second straight tube are arranged perpendicularly, the wire passes through the interior of the arc tube, the exposure head is located outside the end of the second straight tube, the outer wall of the second straight tube is rotatably connected to a plurality of support rods, the plurality of support rods are evenly distributed along the circumference of the second straight tube, a torsion spring is provided between the support rod and the second straight tube, the elastic force of the torsion spring drives the support rod to rotate away from the second straight tube, a pull wire is fixed to the inner wall of the support rod, the pull wire passes through the interior of the arc tube, and the outer wall of the second straight tube is provided with a groove for the support rod to enter.

[0008] By employing the above technical solution, after tightening the pull wires outside the first straight tube, the support rods can be retracted into the slots, allowing the arc tube to be inserted into the test tube. When the pull wires are released, the support rods expand and rotate outward under the elastic force of the torsion springs, with the ends of the support rods contacting the inner wall of the test tube. All the pull wires are manually straightened, controlling the tension to prevent the support rods from rotating. The position of the arc tube is adjusted so that the length of all the pull wires protruding from the first straight tube is the same. This means that the outer ends of all the support rods are at the same distance from the centerline of the second straight tube, meaning that the central axis of the second straight tube coincides with the central axis of the test tube. The exposure head is located at the center of the test tube, achieving centering of the exposure head and the test tube.

[0009] Optionally, a support ring is fixed in the second straight tube, and all the pull wires pass through the support ring.

[0010] By adopting the above technical solution, the support ring contacts the pull wire through the arc-shaped inner wall, and the support ring provides guiding and reversing functions for the pull wire.

[0011] Optionally, an end plate is fixed to the end of the first straight tube, and a plurality of internal through holes are provided on the end plate for the pull wire to pass through. The end of the first straight tube is rotatably connected to a twist block, and a plurality of external through holes are provided in the twist block for the pull wire to pass through. The external through holes are arranged close to the internal through holes, and the pull wire can be clamped between the end plate and the twist block.

[0012] By adopting the above technical solution, when the outer through hole is opposite to the inner through hole, the pull wire can freely enter and exit the first straight tube. When the twist block is rotated, the outer through hole and the inner through hole are staggered, and the pull wire between the twist block and the end plate is bent and deformed. The end plate and the twist block clamp and fix the pull wire to prevent the pull wire from moving spontaneously, making operation easier.

[0013] Optionally, a marking line is provided on the pull wire along its length direction.

[0014] By adopting the above technical solution, the marking line is a length marking line, which makes it easy for personnel to observe the length of the pull wire exposed outside the first straight tube.

[0015] Optionally, the outer sliding sleeve of the first straight tube is provided with a support frame, and two magnet plates are symmetrically fixed to the support frame. The surfaces of the two magnet plates away from the support frame are adsorption surfaces, and the adsorption surfaces are planes, and the two adsorption surfaces are set at an angle.

[0016] By adopting the above technical solution, by simultaneously attaching the adsorption surfaces of the two magnet plates to the surface of the iron pipe, since the two adsorption surfaces are simultaneously tangent to the outer surface of the iron pipe, it is ensured that the first straight pipe is perpendicular to the surface of the iron pipe, and the extension line of the first straight pipe passes through the central axis of the iron pipe, thereby achieving positioning and centering.

[0017] Optionally, a damping shaft is fixed to the exposure head, the damping shaft is connected to the second straight tube in a damping rotation manner, and a coil spring is installed between the damping shaft and the second straight tube.

[0018] By adopting this technical solution, the coil spring stores energy in the rotation of the rotating shaft. Rotating the exposure head tightens the coil spring, and after releasing it, the exposure head can continue to slowly rotate for several revolutions. Because the exposure head rotates slowly and takes a long time, it can rotate several times during the exposure process during testing, improving exposure uniformity, reducing uneven circumferential distribution of radiation, and enhancing detection accuracy.

[0019] In a second aspect, the present application provides a detection process for exposure of the inner wall of a pipeline butt weld, which adopts the following technical solution:

[0020] The detection process for exposing the inner wall of a pipe butt weld seam, using the above-mentioned pipe butt weld seam inner wall exposure device, includes the following steps:

[0021] Step S1: Opening a process hole on the test tube;

[0022] Step S2: inserting the arc tube into the process hole;

[0023] Step S3: When the pull wire is released, the support rod rotates outward under the elastic force of the torsion spring, and the end of the support rod abuts against the inner wall of the test tube;

[0024] Step S4: Straighten all the pull wires manually, control the pulling force so as not to drive the support rod to rotate, and adjust the position of the arc tube so that the length of all the pull wires exposed outside the first straight tube is the same;

[0025] Step S5: starting the gamma-ray flaw detector, exposing the weld on the inner wall of the test tube with an exposure head, and then performing inspection;

[0026] Step S6: After the inspection is completed, all the pull wires are pulled to rotate all the support rods into the corresponding embedded grooves, and the arc tube is pulled out of the process hole.

[0027] By adopting the above technical solution, through the pipeline butt weld inner wall exposure device and its detection process, the arc tube in the detection device can be inserted into the test tube and taken out in the reverse direction, and the support rod and the pull wire can ensure that the exposure head is located on the central axis of the test tube, so there is no need to set a positioning bracket in the test tube.

[0028] Optionally, in step S2, two magnet plates of the support frame contact outer walls of the test tube on both sides of the process hole.

[0029] By adopting the above technical solution, the two magnet plates of the support frame contact the outer walls of the test tube on both sides of the process hole, thereby correcting the first straight tube to ensure that the first straight tube is perpendicular to the surface of the test tube. The extension line of the first straight tube passes through the central axis of the test tube, and at this time, it can be ensured that the second straight tube is parallel to the central axis of the test tube.

[0030] Optionally, in step S2, before inserting the arc tube into the process hole, the exposure head is rotated to tighten the coil spring, so that the exposure head rotates under the action of the coil spring and the damping shaft.

[0031] By adopting the above technical solution, after rotating the exposure head and tightening the coil spring, the exposure head can rotate several times during the exposure process during detection, thereby improving exposure uniformity, reducing the uneven distribution of radiation circumferentially, and improving detection accuracy.

[0032] Optionally, the method further includes step S7: installing a plug or a valve on the process hole.

[0033] By adopting the above technical solution, the process hole is used as a subsequent air release hole, water release hole or detection hole, so that the process hole can play a role in the subsequent time and avoid the structure being useless.

[0034] In summary, this application includes at least one of the following beneficial technical effects:

[0035] 1. The arc tube in the detection device can be inserted into the test tube and taken out in the reverse direction. The support rod and the pull wire can ensure that the exposure head is located on the central axis of the test tube, so there is no need to set a positioning bracket in the test tube;

[0036] 2. This device and process can be adapted to on-site post-weld testing operations without dismantling the pipe, and no objects will be left inside the test pipe. It can also be adapted to test pipes of different diameters, and has a wide range of applicability.

[0037] 3. By setting up a support frame, it is easy to align the first straight tube and the test tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a three-dimensional diagram of a device for exposing the inner wall of a pipe butt weld according to an embodiment;

[0039] Figure 2is a perspective view of the support rod of the embodiment in an expanded state;

[0040] Figure 3 yes Figure 2 A magnified view of point A;

[0041] Figure 4 is a cross-sectional view of a screw block and an end plate of an embodiment;

[0042] Figure 5 is a perspective view of the damping shaft and the coil spring of the embodiment;

[0043] Figure 6 is a perspective view of the exposure device and the test tube in the embodiment;

[0044] Figure 7 This is a cross-sectional view of the exposure device and the test tube according to the embodiment.

[0045] Explanation of the accompanying symbols: 1. Gamma-ray flaw detector; 11. Wire; 12. Exposure head; 2. Arc tube; 21. First straight tube; 22. Bend tube; 23. Second straight tube; 3. Support rod; 31. Torsion spring; 32. Embedded groove; 33. Pull wire; 34. Support ring; 24. End plate; 25. Inner through hole; 4. Twist block; 41. Outer through hole; 35. Marking line; 5. Support frame; 51. Magnet plate; 52. Adsorption surface; 13. Damping shaft; 14. Coil spring; 6. Test tube; 61. Process hole. DETAILED DESCRIPTION

[0046] The present application is further described in detail below with reference to the accompanying drawings. Example

[0047] Reference Figure 1 This embodiment discloses a device for exposing the inner wall of a pipeline butt weld, including a gamma-ray flaw detector 1, an exposure head 12, and a wire 11 connecting the two. The device also includes an arc tube 2, which includes a first straight tube 21, a curved tube 22, and a second straight tube 23 connected in sequence. The first straight tube 21 and the second straight tube 23 are perpendicular to each other. The wire 11 passes through the interior of the arc tube 2, and the exposure head 12 is located outside the end of the second straight tube 23.

[0048] Reference Figure 2 and Figure 3The outer wall of the second straight tube 23 is rotatably connected to a plurality of support rods 3. The support rods 3 are evenly distributed along the circumference of the second straight tube 23 and all have the same length. A torsion spring 31 is disposed between the support rods 3 and the second straight tube 23. The ends of the torsion spring 31 are respectively fixed to the support rods 3 and the second straight tube 23. The elastic force of the torsion spring 31 drives the support rods 3 to rotate away from the second straight tube 23. The outer wall of the second straight tube 23 defines a recess 32 for the support rods 3 to enter. Pull wires 33 are fixed to the inner walls of the support rods 3. The number of pull wires 33 corresponds to the number of support rods 3. The pull wires 33 pass through the interior of the arc tube 2 and exit at the end of the first straight tube 21.

[0049] A support ring 34 is fixed in the second straight tube 23 , and all the pull wires 33 pass through the support ring 34 . The support ring 34 contacts the pull wires 33 through the arc-shaped inner wall, and the support ring 34 provides guidance and reversing functions for the pull wires 33 .

[0050] Reference Figure 2 and Figure 4 The end of the first straight tube 21 is fixed with an end plate 24. The end plate 24 is provided with a plurality of inner through holes 25 for the pull wires 33 to pass through. Each inner through hole 25 contains a pull wire 33. The end of the first straight tube 21 is rotatably connected to a screw block 4. The screw block 4 is provided with a plurality of outer through holes 41 for the pull wires 33 to pass through. Each outer through hole 41 contains a pull wire 33. The outer through holes 41 are arranged near the inner through holes 25, and the pull wires 33 can be clamped between the end plate 24 and the screw block 4. When the outer through holes 41 are directly opposite the inner through holes 25, the pull wires 33 can freely enter and exit the first straight tube 21. When the screw block 4 is rotated, the outer through holes 41 and the inner through holes 25 are offset, and the pull wires 33 between the screw block 4 and the end plate 24 are bent and deformed. The end plate 24 and the screw block 4 clamp and fix the pull wires 33, preventing the pull wires 33 from moving spontaneously.

[0051] A marking line 35 is provided along the length of the pull wire 33. The marking line 35 is a length marking line. The marking line 35 is located at a section of the pull wire 33 close to the first straight tube 21. The marking line 35 makes it easy for people to observe the length of the pull wire 33 exposed outside the first straight tube 21.

[0052] Reference Figure 2 A support frame 5 is slidably mounted on the outside of the first straight tube 21. The support frame 5 comprises a sleeve that slidably engages the first straight tube 21 and two symmetrically arranged inclined plates. The sleeve and inclined plates are secured by welding. Two magnet plates 51 are symmetrically secured to the support frame 5. The two magnet plates 51 are respectively fixed to the bottom surfaces of the two inclined plates. The surfaces of the two magnet plates 51 facing away from the support frame 5 serve as adsorption surfaces 52. The adsorption surfaces 52 are flat and arranged at an angle to each other. By simultaneously attaching the adsorption surfaces 52 of the two magnet plates 51 to the surface of the iron tube, both adsorption surfaces 52 are tangent to the outer surface of the iron tube, thereby ensuring that the first straight tube 21 is perpendicular to the surface of the iron tube, and the extension line of the first straight tube 21 passes through the central axis of the iron tube.

[0053] Reference Figure 5 Exposure head 12 is secured to a damping shaft 13, which is connected to second straight tube 23 for damped rotation. A coil spring 14 is mounted between the damping shaft 13 and second straight tube 23. The inner end of coil spring 14 is secured to the shaft, while the outer end of coil spring 14 is secured to the inner wall of second straight tube 23. Damping shaft 13 is conventional, exhibiting resistance during rotation. Coil spring 14 stores energy for the shaft's rotation. Rotating exposure head 12 tightens coil spring 14, and after loosening, exposure head 12 can continue to slowly rotate for several rotations. Example

[0054] Reference Figure 6 and Figure 7 A detection process for exposing the inner wall of a pipe butt weld seam, using the pipe butt weld seam inner wall exposure device of embodiment 1, comprises the following steps:

[0055] Step S1: A process hole 61 is formed in the test tube 6 at a distance from the weld. It should be noted that the size of the process hole 61 is larger than the outer diameter of the curved tube 2. The support rods 3 on the first straight tube 21 are in a retracted position by default, i.e., within the recesses 32. In this position, the pull wires 33 are positioned longer outside the first straight tube 21. The tightening block 4 and the end plate 24 cooperate to secure all the pull wires 33.

[0056] Step S2: Insert the curved tube 2 into the process hole 61. First, insert the first straight tube 21. Then, as the curved tube 22 is inserted, twist the curved tube 2 accordingly. Once the curved tube 22 is fully inserted into the test tube 6, partially insert the second straight tube 23 until the first straight tube 21 is positioned near the center axis of the test tube 6.

[0057] The two magnet plates 51 of the support frame 5 contact the outer walls of the test tube 6 on both sides of the process hole 61, thereby correcting the first straight tube 21 to ensure that the first straight tube 21 is perpendicular to the surface of the test tube 6. The extension line of the first straight tube 21 passes through the central axis of the test tube 6. At this time, it can be ensured that the second straight tube 23 is parallel to the central axis of the test tube 6.

[0058] Step S3: The pull wire 33 is loosened by rotating the screw block 4, and the support rod 3 rotates outward under the elastic force of the torsion spring 31, and the end of the support rod 3 abuts the inner wall of the test tube 6. The end of the support rod 3 pulls the pull wire 33, shortening the length of the pull wire 33 outside the first straight tube 21.

[0059] Step S4: Manually straighten all the pull wires 33 while controlling the pulling force so as not to drive the support rods 3 to rotate. Adjust the position of the arc tube 2 so that the lengths of all the pull wires 33 exposed outside the first straight tube 21 are the same. At this point, the distances between the outer ends of all the support rods 3 and the center line of the second straight tube 23 are the same, that is, the central axis of the second straight tube 23 coincides with the central axis of the test tube 6, and the exposure head 12 is located at the center of the test tube 6.

[0060] Step S5: Start the gamma-ray flaw detector 1, and use the exposure head 12 to expose the weld on the inner wall of the test tube 6, and then perform inspection.

[0061] Step S6: After the inspection is completed, all the pull wires 33 are pulled to rotate all the support rods 3 into the corresponding embedding grooves 32 , and the arc tubes 2 are pulled out of the process holes 61 .

[0062] Step S7: Install a plug or a valve on the process hole 61 to be used as a subsequent air vent, water drain hole or detection hole, so that the process hole 61 can function in the subsequent time and avoid the structure being useless.

[0063] In step S2, before inserting the arc tube 2 into the process hole 61, the exposure head 12 can be rotated to tighten the coil spring 14, causing the exposure head 12 to rotate under the action of the coil spring 14 and the damping shaft 13. Because the exposure head 12 rotates slowly and takes a long time, it can rotate several times during the exposure process during testing, improving exposure uniformity, reducing circumferential radiation distribution unevenness, and improving detection accuracy.

[0064] In summary, with the present pipeline butt weld inner wall exposure device and its inspection process, the curved tube 2 in the inspection device can be inserted into and removed from the test tube 6. The support rod 3 and the pull wire 33 ensure that the exposure head 12 is positioned on the central axis of the test tube 6, eliminating the need for a positioning bracket within the test tube 6. This device and process are suitable for on-site post-weld inspection operations, eliminating the need for pipe disassembly and preventing objects from being left within the test tube 6. Furthermore, the device and process can accommodate test tubes 6 of varying diameters, demonstrating broad applicability.

[0065] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A device for exposing the inner wall of a pipe butt weld, comprising a gamma-ray flaw detector (1), an exposure head (12), and a wire (11) connecting the two, characterized in that: The invention also includes an arc tube (2), wherein the arc tube (2) includes a first straight tube (21), a curved tube (22) and a second straight tube (23) connected in sequence, wherein the first straight tube (21) and the second straight tube (23) are arranged perpendicularly, the wire (11) passes through the interior of the arc tube (2), the exposure head (12) is located outside the end of the second straight tube (23), the outer wall of the second straight tube (23) is rotatably connected to a plurality of support rods (3), the plurality of support rods (3) are evenly distributed along the circumference of the second straight tube (23), a torsion spring (31) is arranged between the support rod (3) and the second straight tube (23), the elastic force of the torsion spring (31) drives the support rod (3) to rotate away from the second straight tube (23), a pull wire (33) is fixed to the inner wall of the support rod (3), the pull wire (33) passes through the interior of the arc tube (2), and the outer wall of the second straight tube (23) is provided with an embedded groove (32) for the support rod (3) to enter; A support ring (34) is fixed inside the second straight tube (23), and all the pull wires (33) pass through the support ring (34); an end plate (24) is fixed to the end of the first straight tube (21), and a plurality of inner through holes (25) for the pull wires (33) to pass through are provided on the end plate (24); the end of the first straight tube (21) is rotatably connected to a screw block (4), and a plurality of outer through holes (41) for the pull wires (33) to pass through are provided in the screw block (4), and the outer through holes (41) are arranged close to the inner through holes (25), and the pull wires (33) can be clamped between the end plate (24) and the screw block (4); The first straight tube (21) is provided with a support frame (5) on the outer sliding sleeve. The support frame (5) is symmetrically fixed with two magnet plates (51). The surfaces of the two magnet plates (51) away from the support frame (5) are adsorption surfaces (52). The adsorption surfaces (52) are planes, and the two adsorption surfaces (52) are arranged at an angle.

2. The device for exposing the inner wall of a pipe butt weld according to claim 1, characterized in that: The pull line (33) is provided with a marking line (35) along its length direction.

3. The device for exposing the inner wall of a pipe butt weld according to claim 1, characterized in that: The exposure head (12) is fixed with a damping shaft (13), the damping shaft (13) is connected to the second straight tube (23) in a damping rotation manner, and a coil spring (14) is installed between the damping shaft (13) and the second straight tube (23).

4. The detection process for exposure of the inner wall of the pipeline butt weld is characterized by: The device for exposing the inner wall of a pipe butt weld according to any one of claims 1 to 3 is used, comprising the following steps: Step S1: Opening a process hole (61) on the test tube (6); Step S2: inserting the arc tube (2) into the process hole (61); Step S3: loosen the pull wire (33), and the support rod (3) rotates outward under the elastic force of the torsion spring (31), and the end of the support rod (3) abuts against the inner wall of the test tube (6); Step S4: straighten all the pull wires (33) by hand, control the pulling force so as not to drive the support rod (3) to rotate, and adjust the position of the arc tube (2) so that the length of all the pull wires (33) exposed outside the first straight tube (21) is the same; Step S5: starting the gamma-ray flaw detector (1), exposing the weld seam on the inner wall of the test tube (6) with the exposure head (12), and then performing inspection; Step S6: After the inspection is completed, all the pull wires (33) are pulled to rotate all the support rods (3) into the corresponding embedded grooves (32), and the arc tube (2) is pulled out of the process hole (61).

5. The process for detecting exposure of the inner wall of a pipeline butt weld according to claim 4, characterized in that: In step S2, the two magnet plates (51) of the support frame (5) contact the outer walls of the test tube (6) on both sides of the process hole (61).

6. The process for detecting exposure of the inner wall of a pipeline butt weld according to claim 4, characterized in that: In step S2, before inserting the arc tube (2) into the process hole (61), the exposure head (12) is rotated to tighten the coil spring (14), so that the exposure head (12) rotates under the action of the coil spring (14) and the damping shaft (13).

7. The process for detecting exposure of the inner wall of a pipeline butt weld according to claim 4, characterized in that: The method further comprises step S7: installing a plug or a valve on the process hole (61).

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