JP2007285772A - Pipe inspection method, and pipe inspection device used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe inspection method and device, capable of inspecting efficiently and quickly the whole face of a pipe inner face from a pipe outer face, without modifying a pipe. <P>SOLUTION: A scanning tool 2 includes a pair of sensors 30 30 arranged symmetrically with respect to the center of the pipe 100. The pair of sensors 30, 30 is rotatable along a circumferential direction of the pipe 100, and wall thickness reduction is detected over the whole inner face of the pipe 100 by the pair of sensors 30, 30, by making the scanning tool 2 travel on an outer face of the pipe 100. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pipe inspection method and a pipe inspection apparatus used therefor. More specifically, the present invention relates to a pipe inspection method for detecting a thinning of the pipe inner surface by a sensor provided in a scanning jig that scans the pipe outer surface in the longitudinal direction of the pipe, and a pipe inspection apparatus used therefor.

  Conventionally, as a method for detecting defects such as thinning and corrosion of the inner surface of a pipe such as a crude oil pipeline, for example, a defect inspection method using an inspection pig as disclosed in Patent Documents 1 and 2 is known. The inspection pig is inserted into the pipe and travels in the pipeline to inspect the inner surface of the pipe for defects.

  However, since the inspection apparatus described in Patent Document 1 causes the inspection pig to run by the fluid in the pipe, it cannot be inspected if there is no fluid inside the pipe.

  Further, the inspection pig described in Patent Document 2 travels inside the pipe not by the fluid in the pipe but by the towing cart. However, since the number of components such as a towing cart increases, the structure becomes complicated and the handling becomes complicated.

Furthermore, since the inspection pig as described above is inserted into the pipe, depending on the pipe structure, the pipe itself may need to be modified, resulting in high costs. Further, since the inspection pig travels inside the pipe, it is difficult to quickly collect the inspection pig in an emergency or the like.
JP 61-38536 A JP 2005-181139 A

  In view of the conventional situation, the present invention provides a pipe inspection method and a pipe inspection apparatus capable of inspecting the entire inner surface of a pipe efficiently and at high speed from the outer surface of the pipe without modifying the pipe. Objective.

  In order to achieve the above object, a pipe inspection method according to the present invention is characterized in that a pipe inspection method for detecting thinning of an inner surface of a pipe with a sensor provided in a scanning jig that runs in the longitudinal direction of the pipe, The jig includes a pair of the sensors arranged symmetrically with respect to the center of the pipe, the pair of sensors is rotatable in the circumferential direction of the pipe, and the pair of sensors is caused to run on the outer surface of the pipe by moving the scanning jig. This is to detect the thinning of the entire inner surface of the pipe.

  With the above configuration, the pair of sensors are arranged symmetrically, so that the balance of the entire scanning jig is maintained and thinning can be detected with high accuracy. Furthermore, since the pair of sensors can rotate in the circumferential direction of the pipe, the entire surface of the pipe can be inspected at high speed.

  Moreover, it is desirable that the sensor is attached to the scanning jig via a tightening mechanism that maintains a contact state with the pipe. If the sensor vibrates during scanning, the inspection accuracy is lowered, so that the contact state must be maintained. On the other hand, in order to rotate the sensor, it is necessary to release the contact state with respect to the piping to make it free. Therefore, with the above configuration, the sensor is fixed to the pipe by the tightening pressure, so that the sensor does not vibrate during scanning, and a decrease in inspection accuracy can be prevented. Furthermore, by loosening the tightening pressure during rotation, the sensor can be easily rotated without removing the sensor, and the entire surface of the pipe can be inspected efficiently and at high speed.

  You may make it measure the thickness of piping by ultrasonic flaw detection with respect to the thinning location which detected the said thinning.

  The scanning jig includes a first scanning jig having the pair of sensors and a second scanning jig having a carriage, and the sensor of the second scanning jig transmits ultrasonic waves to the outer surface of the pipe. A plurality of probes for receiving, the sensor may be attached to a position facing the lower part of the pipe of the carriage, and the thickness of the lower surface of the pipe may be measured.

  In order to achieve the above object, the pipe inspection apparatus according to the present invention is characterized in that the thinning of the pipe inner surface is detected by a scanning jig provided with a sensor that scans the pipe outer surface in the longitudinal direction of the pipe. A pipe inspection apparatus for use in the pipe inspection method, wherein the scanning jig includes a pair of sensors arranged symmetrically with respect to a center of the pipe, and the pair of sensors is rotatable in a circumferential direction of the pipe, The scanning jig is moved on the outer surface of the pipe, and the thinning of the entire inner surface of the pipe is detected by the pair of sensors.

  According to the features of the pipe inspection method and the pipe inspection apparatus according to the present invention, it is possible to inspect the entire inner surface of the pipe efficiently and at high speed from the outer surface of the pipe without modifying the pipe.

  Other objects, configurations, and effects of the present invention will become apparent from the following embodiments of the present invention.

Next, the present invention will be described in more detail with reference to the accompanying drawings as appropriate.
As shown in FIG. 1, a pipe inspection apparatus 1 according to the present invention generally includes a first scanning jig 2 that travels on a pipe 100 and scans the entire surface of the pipe 100, an operation unit 3, and a control unit 4. Become. The operation unit 3 is connected to the first scanning jig 2 via the connection box 4 and performs operations such as running of the first scanning jig 2. In addition, the control unit 4 adjusts the current supplied from the power source 5 to the scanner unit 30 of the first scanning jig 2 and processes the signal detected by the scanner unit 30 to detect the position and size of the defect. Map display, recording, etc. In the present embodiment, the pipe 100 is a crude oil pipe.

  As shown in FIG. 2, the first scanning jig 2 includes a circular frame 10 having a diameter slightly larger than the diameter of the pipe 100 and a drive unit 20 that causes the first scanning jig 2 to travel in the longitudinal direction of the pipe 100. And a pair of sensor units 30 and 30.

  As shown in FIGS. 2 and 3, the frame 10 includes a semicircular upper frame 11 and a lower frame 12, and the upper and lower frames 11 and 12 are thin plate-like first frames 11a and 12a and second frames 11b and 12b. Are connected in parallel by a plurality of connecting members 13. The upper and lower frames 11 and 12 are connected by a fixture 14a such as a bolt at a connecting portion 14 provided at the tip thereof. The upper frame 11 is provided with a mounting portion 15 for attaching the pair of sensor units 30, 30 so as to be symmetric with respect to the center of the pipe 100.

  The attachment portion 15 includes a thin plate-like attachment plate 16 fixed to the upper frame 11, a fastening mechanism 17, and an attachment frame 18 that fixes the scanner unit 30.

  As shown in FIG. 3B, the tightening mechanism 17 is generally composed of a cylinder 17a, a connecting plate 17c, and a swivel joint 17e. The cylinder 17a is rotatably attached to both ends of the mounting plate 16, and the other end is connected to the connecting plate 17c via a connecting rod 17b. The connecting plate 17 is connected to the rotating shaft 17d of the upper frame 11 and the swivel joint 17e. The swivel joint 17e is slidably attached to a slide groove 17f provided in the upper frame 11 along the radial direction, and is connected to the attachment frame 18 so as to be rotatable.

  Therefore, in the tightening mechanism 17, the connecting rod 17b moves forward and backward by driving the cylinder 17a, and the connecting plate 17c rotates about the rotary shaft 17d in conjunction with the forward and backward movement. In conjunction with the rotation, the swivel joint 17e slides and / or rotates along the slide groove 17f, and the sensor unit 30 is operated. As a result, while the first scanning jig 2 is traveling, the sensor unit 30 can be securely fixed along the pipe 100 to maintain the contact state, and accurate defect detection can be performed. . Furthermore, when the frame 10 described later is rotated, the contact state of the sensor unit 30 with the pipe 100 can be easily released before the rotation, and the work can be easily performed.

  As shown in FIGS. 2 and 4, the drive unit 20 generally includes a drive frame 21, a pair of first and second wheels 23 a and 23 b, and a frame rotation mechanism 26. The drive frame 21 is connected by a connecting member 22 so that a first frame 21a and a second frame 21b formed in a substantially U-shape are parallel to each other. The width of the drive frame 21 is formed wider than the width of the frame 10 so as to cover the frame 10. A pair of first and second wheels 23 a and 23 b are attached to the outer side of the drive frame 21, and a frame rotation mechanism 26 is provided on the inner side.

  The first and second wheels 23 a and 23 b are formed to be inclined from both ends toward the center so as not to drop off from the upper surface of the pipe 100. The wheel surface is covered with an elastic member such as rubber in order to suppress vibration during traveling without damaging the surface of the pipe 100. Further, a cover 24 is provided on the first and second wheels 23a and 23b, and a connector 25 connected to the sensor unit 30 and the control unit 4 is provided on the upper portion of the first wheel 23a.

  The frame rotation mechanism 26 is a mechanism that rotates the frame 10 along the circumferential direction of the pipe 100, and includes a pair of attachment plates 27, a plurality of rollers 28, and a motor 29. A motor 29 is connected to the mounting plate 27 in such a manner that four rollers 28 are vertically arranged along the peripheral surface of the frame 10 so as to sandwich the frame 10 therebetween. Therefore, the frame 10 can be rotated in the circumferential direction of the pipe 100 by driving the motor 29, and the pair of sensor units 30 attached to the frame 10 can be arranged at arbitrary positions on the circumferential surface of the pipe 100. It is possible to perform a full inspection.

  The sensor unit 30 shown in FIG. 5 includes a sensor 31, a pair of wheels 32 a and 32 b, and a connector 33. The sensor 31 is an eddy current flaw detection sensor, which generates a magnetic flux by an excitation coil in the sensor 31 and detects turbulence of the eddy current due to a defect in the piping 100 caused by the magnetic flux based on an impedance or a voltage change of the detection coil. The detected signal is sent to the control unit 4 from the connector 33, and the position and size of the defect are displayed on a map. Further, a magnetic saturation coil is provided in the sensor 31, and the current supplied from the power source 5 is adjusted by the control unit 4 so as to make the magnetism uniform and suppress the influence of noise.

  Further, the surface 31 a of the sensor 31 is formed to be curved along the peripheral surface of the pipe 100. The pair of wheels 32 a and 32 b are attached to the side surfaces of the sensor 31 so as to be inclined with respect to the sensor 31 so as to contact the surface of the pipe 100.

Next, a pipe lower part inspection apparatus for inspecting the lower part of the pipe 100 will be described with reference to FIGS.
The pipe inspection apparatus 40 shown in FIG. 6 measures the thickness of the lower part of the pipe 100 where defects such as thinning are likely to occur. In general, the pipe inspection apparatus 40 operates with a tank 41 that stores water W as a contact medium. It consists of a part 42 and a second scanning jig 50. These are connected by a cable 54, a water supply hose 55, and a drainage hose 56, and the water W is circulated through the water supply hose 55 and the drainage hose 56. The operation unit 42 controls the amount of water supplied to the sensor unit 83 described later and the traveling of the carriage 60. Further, the operation unit 42 processes the signal detected by the sensor unit 83, calculates the thickness of the lower part of the pipe 100, and displays, records, and the like. Usually, since there is a high possibility that defects such as thinning will occur in the lower part of the pipe 100, the pipe inspection efficiency is improved by measuring the thickness of the lower part of the pipe 100.

  The second scanning jig 50 includes a rail 51 fixed on the pipe 100 and a carriage 60 that travels on the rail 51. The rail 51 is formed to a predetermined length, and wheel stoppers 52 are provided at both ends thereof, and is fixed to the upper portion of the pipe 100 by a fixture 53 at an appropriate interval.

  As shown in FIGS. 7 and 8, the carriage 60 generally includes a frame 61, a drive unit 70, and a sensor unit 80. The frame 61 is composed of a substantially semicircular upper frame 62 and a lower frame 63. The upper and lower frames 62, 63 are parallel to each other by a thin plate-like first frame 62a, 63a and second frames 62b, 63b by connecting members 64, respectively. It is connected to become. The upper frame 62 and the lower frame 63 are connected at the ends of the upper and lower frames 62, 63 by a hinge 65b, and are connected by a lock 65a at a connection plate 65 provided at the other end.

  The upper frame 62 is provided with a pair of side rollers 66 a and 66 a at positions that are substantially symmetrical with respect to the center of the pipe 100. A drive unit 70 that travels on a rail 51 attached to the upper surface of the pipe 100 is attached to the upper part of the upper frame.

  In addition, the portion of the lower frame 63 that faces the lower portion of the pipe 100 is formed wider than the portion that faces the side surface, and a groove 63 c that slides the sensor unit 80 is formed. The sensor unit 80 is fixed to the groove 63c by a clamp 67.

  The drive unit 70 includes a pair of first and second drive units 71 and 72 and is attached to the first and second frames 62 a and 62 b of the upper frame 62. The second wheels 73a and 73b are fitted to the rail 51. Further, proximity switches 74 a and 74 b are provided outside the first and second drive units 71 and 72 to monitor the proximity to the wheel stopper 52. Further, the first drive unit 71 is provided with a motor 75 and an encoder 76, and the encoder 76 detects the travel distance of the carriage 60.

  As shown in FIGS. 9 to 11, the sensor unit 80 generally includes a base 81, a sensor base 82, and a sensor unit 83. The base 81 is provided with a hole 81a through which the shaft 82a provided in the sensor base 82 passes, and a linear bush 81b through which the shaft 82a passes is attached. A compression spring 81c is attached between the base 81 and the sensor base 82, and a shaft 81d is slidably attached to the base 81 and the sensor base 82. Further, a ball caster 87 is attached to the base 81. Therefore, the sensor base 82 can move up and down with respect to the base 81, and the elastic force of the compression spring 81c causes the sensor portion 83 to be in close contact with the lower part of the pipe 100 and absorbs vibrations and the like during travel. Thickness can be measured.

  A sensor unit 83 is attached to the sensor base 82. As shown in FIG. 11, the sensor portion 83 is curved and formed so as to be in close contact with the lower surface of the pipe 100. The sensor unit 83 is surrounded by a substantially square flange 83a, and a plurality of probes 84, a water supply nozzle 85, and a drainage nozzle 86 are disposed inside the sensor unit 83. The flange 83a slightly protrudes from the surface of the sensor unit.

  As shown in FIG. 9, four probes 84 are arranged in a row at the same pitch interval in the sensor unit 83, and four rows of the probes are arranged. Adjacent probe rows are arranged such that each pitch between the probes 84 is not continuous in the vertical direction. With the arrangement of the probe 84 as described above, it is possible to prevent the thickness measurement point from coming off and improve the inspection accuracy.

  The probe 84 is a probe in which a transmitter and a receiver are integrated. An ultrasonic pulse is incident on the lower part of the pipe 100 and the reflected wave is received to measure the thickness of the pipe 100. To do. Since the surface of the pipe 100 is painted, the thickness to be measured is the thickness of the pipe excluding the coating thickness.

  On both sides of the sensor unit 83, a water supply nozzle 85 and drainage nozzles 86 are provided on both sides of the water supply nozzle 85. Water W as a contact medium is supplied from the water supply nozzle 85 through the water supply manifold 85a and the water supply coupler 85b from the water supply nozzle 85, and is discharged from the water discharge nozzle 86 to the tank 41 through the water discharge manifold 86a and the water discharge coupler 86b. Circulate. The circulation of the water W and the protrusion of the flange 83a from the surface of the sensor unit 83 prevent water leakage to the outside of the sensor unit 83.

Next, a pipe inspection procedure using the two types of inspection apparatuses will be described.
First, the driving unit 20 of the first scanning jig 2 is positioned at the center of the upper frame 11, and the upper frame 11 is covered from the upper part of the piping 100 so that the driving unit 20 contacts the upper surface of the piping 100. Fit into 100. And it connects with the lower frame 12 mounted in the piping 100 lower part and the connection part 13 with the fixing tool 13a. Next, the sensor units 30 and 30 are attached to the upper frame 11 and fixed by the tightening mechanism 17 so that the sensor units 30 and 30 are in contact with the pipe 100. After fixing the sensor units 30, 30, the first scanning jig 2 is caused to travel in the longitudinal direction of the pipe 100 via the operation unit 3. The upper frame 11 may be fitted to the pipe 100 in the horizontal direction from the side surface of the pipe 100 by positioning the drive unit 20 at the end of the upper frame 11 by the frame rotation mechanism 26.

  Next, when scanning for a predetermined distance is completed, the tightening mechanism 17 releases the contact state between the sensor units 30 and 30 and the pipe 100, and the frame rotation mechanism 26 rotates the frame 10 along the circumferential direction of the pipe 100. Thus, the sensor units 30 and 30 are arranged at positions facing the surface of the pipe 100 that has not been scanned.

  Then, after determining the arrangement of the sensor units 30, 30, the sensor units 30, 30 are fixed by the tightening mechanism 17 so as to be in contact with the pipe 100. Then, the first scanning jig 2 is caused to travel in the direction opposite to the previous scanning direction.

  When the scanning of the predetermined distance is completed, the tightening mechanism 17 releases the contact state between the sensor units 30 and 30 and the pipe 100, and the frame rotating mechanism 26 faces the surface of the pipe 100 that has not been scanned. The sensor units 30 and 30 are arranged at the positions and fixed again by the tightening mechanism 17. This procedure is repeated until scanning of the entire surface of the pipe 100 is completed. During scanning, the signal detected by the sensor 31 is transmitted to the control unit 6 and recorded as needed.

  After the scanning of the pipe 100 is completed, the signal detected by the control unit 6 is signal-processed to display the position and size of the defective part as a map. Then, the thickness of the defective portion determined to be a thinned portion based on the scanning result is measured by ultrasonic flaw detection with respect to the defective portion to determine whether or not it is a defect. According to the above procedure, a defective part is detected and the thickness measurement is performed only on the defective part, so that the entire surface of the pipe 100 can be inspected efficiently and at high speed.

Furthermore, about the lower part of the piping 100, the rail 51 is fixed to the piping 100, the trolley | bogie 60 is made to travel, and the thickness of the lower part of the piping 100 is measured.
First, the rail 51 is attached to the upper surface of the pipe 100 by the fixture 53, the first and second wheels 71 and 72 of the drive unit 70 are fitted to the rail 51, and the upper frame 61 and the sensor unit 80 are fixed to the lower frame. 62 is connected by a lock 65a. Then, the drive unit 70 is operated to cause the carriage 60 to travel in the longitudinal direction of the pipe 100.

  While the carriage 60 is running, water W is supplied to and drained from the sensor unit 83, ultrasonic pulses are incident on the pipe 100 from the plurality of probes 84, and reflected waves from the pipe 100 are received. The received signal is transmitted to the operation unit 42. When the traveling is completed, the operation unit 42 processes the received signal and displays the thickness of the pipe 100 excluding the coating thickness. Usually, there is a high possibility that defects such as thinning will occur in the lower part of the pipe 100, so that the inspection efficiency is improved by measuring the thickness of the entire lower part.

Finally, mention is made of the possibilities of other embodiments.
In the above embodiment, first, the entire surface of the pipe was inspected to detect a defective portion, the thickness of the defective portion was measured, and then the thickness of the entire lower surface of the pipe was measured. However, the thickness measurement of the lower portion of the pipe may be performed prior to the entire inspection of the pipe 100. Further, the thickness measurement of the lower part of the pipe can be performed independently of the entire inspection of the pipe 100 by the first scanning jig 2 described above.

  Moreover, in the said embodiment, the 1st scanning jig | tool 2 provided the drive unit 20 which self-runs on the piping 100. FIG. However, a rail may be attached to the upper part of the pipe so as to travel on the rail.

  INDUSTRIAL APPLICABILITY The present invention can be used as a pipe inspection method and apparatus for detecting defects such as thinning of the entire inner surface of crude oil pipes. Moreover, it is not restricted to crude oil piping, It can utilize also as the inspection method and inspection apparatus of the inner surface whole surface of various tubular bodies.

It is the schematic which shows the piping inspection apparatus which concerns on this invention. It is a perspective view which shows the 1st scanning jig | tool in a piping inspection apparatus. (A) is a perspective view which shows the upper frame in a piping inspection apparatus, (b) is the elements on larger scale of the clamping mechanism vicinity in a piping inspection apparatus. It is the elements on larger scale of the drive unit in a piping inspection apparatus. It is the elements on larger scale of the sensor unit in a piping inspection apparatus. It is a side view which shows the piping lower part inspection apparatus which test | inspects the lower part of piping. It is a side view of the trolley | bogie in a piping lower part inspection apparatus. It is a front view of the trolley | bogie in a piping lower part inspection apparatus. It is a top view of the sensor unit in a piping lower part inspection device. It is a pipe radial direction view of the sensor unit in the pipe lower part inspection apparatus. It is a pipe axial direction view of the sensor unit in a pipe lower part inspection device.

Explanation of symbols

1: piping inspection device, 2: first scanning jig, 3: operation unit, 4: control unit, 5: connection box, 6: power supply, 10: frame, 11: upper frame, 11a: upper first frame, 11b : Upper second frame, 12: lower frame, 12a: lower first frame, 12b: lower second frame, 13: connecting member, 14: connecting portion, 14a: fixing tool, 15: mounting portion, 16: mounting plate, 17: Tightening mechanism, 17a: cylinder, 17b: connecting rod, 17c: connecting plate, 17d: rotating shaft, 17e: swivel joint, 17f: slide groove, 18: mounting frame, 20: drive unit, 21: frame, 21a : First frame, 21b: Second frame, 22: Connecting member, 23a: First wheel, 23b: Second wheel, 24: Cover, 25: Connector, 26: Frame rotation mechanism, 27: Mounting plate, 28: Low -, 29: motor, 30: sensor unit, 31: sensor, 31a: surface, 32a: first wheel, 32b: second wheel, 33: connector, 40: pipe inspection device, 41: tank, 42: operation unit, 50: Second scanning jig, 51: Rail, 52: Wheel stopper, 53: Fixing tool, 54: Cable, 55: Water supply hose, 56: Drain hose, 60: Dolly, 61: Frame, 62: Upper frame, 62a : Upper first frame, 62b: Upper second frame, 63: Lower frame, 63a: Lower first frame, 63b: Lower second frame, 63c: Groove, 64: Connecting member, 65: Connection plate, 65a: Lock, 65b: hinge, 66a: side roller, 66b: caster, 67: clamp, 70: drive unit, 71: first drive unit, 72: second drive unit, 73a: first wheel, 73b: second wheel, 4a, b: proximity switch, 75: motor, 76: encoder, 80: sensor unit, 81: base, 81a: hole, 81b: linear bush, 81c: compression spring, 81d: shaft, 82: sensor base, 82a: Shaft, 83: Sensor section, 83a: Flange, 84: Probe, 85: Water supply nozzle, 85a: Water supply manifold, 85b: Water supply coupler, 86: Drain nozzle, 86a: Drain manifold, 86b: Drain coupler, 87: Ball Casters, 88: handle, 100: piping, W: water (contact medium)

Claims (5)

A pipe inspection method for detecting thinning of the inner surface of a pipe with a sensor provided in a scanning jig that runs in the longitudinal direction of the pipe,
The scanning jig includes a pair of the sensors arranged symmetrically with respect to the center of the pipe, the pair of sensors is rotatable in a circumferential direction of the pipe, and the scanning jig runs on an outer surface of the pipe so that the pair A pipe inspection method characterized by detecting a thinning of the entire inner surface of a pipe by means of a sensor. The pipe inspection method according to claim 1, wherein the sensor is attached to the scanning jig through a tightening mechanism that maintains a contact state with the pipe. The pipe inspection method according to claim 1, wherein the thickness of the pipe is measured by ultrasonic flaw detection at the thinned portion where the thinning is detected. The scanning jig includes a first scanning jig having the pair of sensors and a second scanning jig having a carriage, and the sensor of the second scanning jig transmits ultrasonic waves to the outer surface of the pipe. 2. The pipe inspection method according to claim 1, wherein the plurality of probes are received, the sensor is attached to a position facing a lower pipe of the carriage, and a thickness of a lower surface of the pipe is measured. . A pipe inspection apparatus used for a pipe inspection method according to any one of claims 1 to 4, wherein a thinning of the pipe inner surface is detected by a scanning jig provided with a sensor that scans the pipe outer surface in the longitudinal direction of the pipe,
The scanning jig includes a pair of the sensors arranged symmetrically with respect to the center of the pipe, the pair of sensors is rotatable in a circumferential direction of the pipe, and the scanning jig runs on an outer surface of the pipe so that the pair A pipe inspection apparatus for detecting a thinning of the entire inner surface of a pipe by means of a sensor.