JP2013108936A - Method of ultrasonically measuring tube thickness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of ultrasonically measuring tube thickness which allows for reliably securing a guide tube inside a boiler header and facilitates positioning of the guide tube along the longitudinal direction of the boiler header.SOLUTION: A method of ultrasonically measuring tube thickness is provided, where a cable is inserted from an inspection port 53 formed on a boiler header 51 into a boiler tube 52 connected with the boiler header 51 via a guide tube 3 to measure boiler tube thickness using an ultrasonic sensor probe attached to the cable. The method includes; a rail laying step for laying a rail 9 that extend along the longitudinal direction of the boiler header 51; a guide tube fixation step for securing an end of the guide tube 3 to the rail 9; and a guide tube moving step for moving the guide tube 3 along the rail 9.

Description

  The present invention relates to an ultrasonic wall thickness measuring method, and more particularly to an ultrasonic wall thickness method suitable for boiler wall thickness measurement.

Boiler tubes require periodic wall thickness measurements. As a general boiler tube thickness measuring method, an inner UT method, a water immersion UT method, and the like are known.
In particular, when measuring the thickness of the boiler tube connected to the header, the measurement is performed by the inner UT method. In this method, an ultrasonic probe (sensor probe) is inserted into the boiler tube. In order to do this, it is necessary to cut the boiler tube itself. Further, it is necessary to apply fluid pressure such as water flow in order to insert the ultrasonic probe into the boiler tube. Therefore, the apparatus for measuring the wall thickness is large and there is a drawback that the cost is high.

  On the other hand, for example, when trying to measure the boiler tube of a garbage incineration boiler, it is often impossible to cut the boiler tube, so a method of measuring the wall thickness from the outer surface of the boiler tube by building a scaffold in the furnace is adopted. Has been. This method has problems such as higher measurement accuracy and reduced scaffolding costs.

  On the other hand, for example, Patent Document 1 proposes a method for measuring the thickness of a boiler tube without cutting the boiler tube by using a guide device having a guide tube. That is, in the technique of Patent Document 1, a guide tube is introduced into a header through an inspection hole formed in the header, and the tip of the guide tube is introduced into the boiler tube by passing through the header. Thereafter, an ultrasonic probe is introduced into the guide tube from the inspection hole side, and the ultrasonic probe is advanced. As a result, the ultrasonic probe advances along the guide tube, that is, is guided into the guide tube and is introduced into the boiler tube.

JP 2001-305110 A

However, since the technique of Patent Document 1 employs a method of fixing the guide tube to the boiler tube with an electromagnet, there is concern about the fixing force of the guide tube, and the guide tube may come off the boiler tube. was there.

  That is, since the inner wall surface of the boiler tube has a curved shape, it is necessary to make the shape of the electromagnet along the inner wall surface in order to strengthen the fixing force by the electromagnet. However, since the curved shape of the inner wall surface of the boiler tube is not uniform, an electromagnet having a specific shape cannot cope with all boiler tubes, and the fixing force by the electromagnet may not be sufficiently obtained.

  Further, when the inspection hole and the boiler tube are in a torsional positional relationship, there is a problem in that a sufficient fixing force cannot be obtained because the guide tube has to face a complicated direction.

  The present invention has been made in consideration of such circumstances, and the object thereof is to enable the guide tube to be fixed securely and to easily align the header in the direction along the longitudinal direction of the header. It is in providing the ultrasonic thickness measuring method which can be performed to.

In order to achieve the above object, the present invention provides the following means.
The ultrasonic wall thickness measuring method of the present invention is a method in which a cable is inserted through a guide tube into a boiler tube connected to the header from an inspection hole formed in the header, and an ultrasonic wave provided on the cable. An ultrasonic wall thickness measuring method for measuring the wall thickness of the boiler tube with a sensor probe for measurement, the rail laying step of laying a rail so as to extend in the longitudinal direction of the header, and the rail to the rail A guide tube fixing step of fixing the tip of the guide tube; and a guide tube moving step of moving the guide tube along the rail.

  According to the above configuration, since the rail is laid in the header and the guide tube is fixed to the rail, the guide tube can be reliably fixed in the header. Moreover, since the guide tube can be moved along the rail, the guide tube can be easily aligned in the direction along the longitudinal direction of the header.

  In the ultrasonic thickness measurement method, the rail is configured by a roller chain that is annularly connected outside the inspection hole, and the guide tube is connected via an attachment member that can be connected to the roller chain. And preferably connected to the roller chain.

  According to the above configuration, the guide tube in the direction along the longitudinal direction of the header can be easily aligned by operating and rotating the annularly connected roller chain outside the inspection hole.

  Further, in the ultrasonic thickness measurement method, the rail laying step includes a step of inserting the roller chain from the first inspection hole and pulling it out from the second inspection hole via the header, and the outside of the inspection hole. A step of connecting the roller chain into an annular shape and a step of applying tension to the roller chain by arranging a plurality of sprockets inside the header, wherein the guide tube moving step rotates the roller chain. It is preferable to move the guide tube by moving the guide tube.

  According to the said structure, slack of a roller chain can be prevented by giving tension | tensile_strength to a roller chain with a sprocket, and position alignment of a guide tube can be performed more smoothly.

  In the ultrasonic wall thickness measuring method, the rail includes a guide rail composed of a plurality of guide rail pieces connected to each other, and a carriage that can be slidably attached to the guide rail. The pipe may be attached to the guide rail via the carriage, and the guide pipe moving step may be performed by pulling the carriage with a wire.

  According to the above configuration, the guide tube can be easily aligned in the direction along the longitudinal direction of the header by moving the carriage.

  In the ultrasonic wall thickness measuring method, the rail laying step includes inserting the guide rail from the first inspection hole and extending the guide rail to the position of the second inspection hole. It is preferable to include a step of fixing the guide rail at the positions of the one inspection hole and the second inspection hole.

  According to the above configuration, by fixing the guide rail, it is possible to prevent the guide rail from being loosened, and to align the guide tube more smoothly.

  In the ultrasonic wall thickness measuring method, it is preferable that the guide tube is configured to be able to bend its distal end by remote operation, and further includes a guide tube bending step of bending the distal end of the guide tube.

  According to the above configuration, since the distal end of the guide tube can be bent by remote operation, the distal end of the guide tube can be bent in the direction of the boiler tube, and the sensor probe can be guided more smoothly to the boiler tube. Can do.

  According to the present invention, since the rail is laid in the header and the guide tube is fixed to the rail, the guide tube can be reliably fixed in the header. Moreover, since the guide tube can be moved along the rail, the guide tube can be easily aligned in the direction along the longitudinal direction of the header.

1 is an overall schematic diagram of an ultrasonic thickness measuring unit and a boiler according to an embodiment of the present invention. It is the schematic of the guide pipe | tube which concerns on 1st embodiment of this invention, (a) A side view of a guide pipe | tube, (b) It is AA sectional drawing of (a). It is a figure explaining the rail laying process of the ultrasonic thickness measuring method which concerns on 1st embodiment of this invention. It is a figure explaining the rail laying process of the ultrasonic thickness measuring method which concerns on 1st embodiment of this invention. It is an enlarged view of the chain fixing member which gives tension to a roller chain. It is a figure explaining the guide tube moving process of the ultrasonic thickness measuring method which concerns on 1st embodiment of this invention. It is a figure explaining the guide pipe bending process of the ultrasonic thickness measuring method which concerns on 1st embodiment of this invention. It is a figure explaining the guide pipe bending process of the ultrasonic thickness measuring method which concerns on 1st embodiment of this invention. It is a side view of the guide rail which concerns on 2nd embodiment of this invention. FIG. 10 is a top view of the guide rail, as viewed in the direction of arrow B in FIG. 9. It is C arrow line view of FIG. It is a perspective view of the trolley | bogie which concerns on 2nd embodiment of this invention. It is a figure explaining the rail laying process of the ultrasonic thickness measuring method which concerns on 2nd embodiment of this invention. It is a figure explaining the rail laying process of the ultrasonic thickness measuring method which concerns on 2nd embodiment of this invention. It is a front view of the holding tool which holds a guide tube. It is D arrow line view of FIG. It is a figure explaining the guide tube moving process of the ultrasonic thickness measuring method which concerns on 2nd embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment of an ultrasonic thickness measuring method according to the present invention will be described in detail with reference to the drawings. The ultrasonic thickness measuring method according to the present embodiment is used for measuring the thickness of the boiler tube 52 in the boiler 50.

  As shown in FIG. 1, the boiler 50 includes a header 51 and a plurality of boiler tubes 52. The boiler tube 52 is a plurality of small-diameter pipes that serve as steam flow paths, and is arranged along the axial direction of the header 51, and one end is connected to the header 51. These boiler tubes 52 are in communication with the header 51 and extend from the header 51 obliquely downward. In addition, a plurality of first inspection holes 53 and second inspection holes 54 for inspection are opened apart from each other in the axial direction of the header 51 at the upper portion of the header 51. The inspection hole 53 and the boiler tube 52 are arranged so as to have a twisted positional relationship.

Next, the ultrasonic thickness measuring unit 1 will be described.
The ultrasonic thickness measurement unit 1 includes a data collection device 31, a data analysis device 32 that analyzes data collected by the data collection device 31, a cable winding device 33 connected to the data collection device 31, and a cable winding device. It has the cable 30 discharged | emitted from the apparatus 33, the sensor probe 2 attached to the front-end | tip of the cable 30, and the guide tube 3. FIG.

The cable 30 is a long member made of, for example, metal or vinyl, and can be bent over its entire length.
The sensor probe 2 is provided at the tip of the cable 30 and can measure the thickness data of the boiler tube 52 by emitting ultrasonic waves. The cable 30 is integrally provided with wiring connected to the sensor probe 2 and a wire 10 (see FIG. 3) for extending and contracting operation.

The cable winding device 33 is connected to the rear end of the cable 30 and is used for winding the cable 30 inserted into the boiler tube 52.
In the data collection device 31, the wall thickness data of the boiler tube 52 measured by the sensor probe 2 is input via the cable 30. That is, the data collection device 31 has a role of collecting the wall thickness data of the boiler tube 52.
The data analysis device 32 is a computer used for analyzing the wall thickness data of the boiler tube 52 collected by the data collection device 31.

The guide tube 3 is a tube that guides introduction of the cable 30 and the sensor probe 2 into the boiler tube 52, and is arranged in the header 51 before measuring the thickness of the boiler tube 52.
As shown in FIG. 2, the guide tube 3 is configured by connecting a plurality of cylinders 4. Each cylinder 4 is cut off obliquely when viewed from a direction (radial direction) perpendicular to the axial direction, with one end surface 4a and the other end surface 4b in the axial direction. That is, one end surface 4a and the other end surface 4b in the axial direction of the cylinder 4 are inclined with respect to a surface orthogonal to the axial direction. Further, the two end surfaces 4 a and 4 b of each cylinder 4 are formed so as to be plane symmetric with respect to the center plane M orthogonal to the center axis of the cylinder 4.

  Each cylinder 4 is an end portion in the longitudinal direction via a hinge 5, and the end portions at positions where the dimension in the longitudinal direction is the longest are connected to each other. Since the end faces 4 a and 4 b of the cylinder 4 are cut off obliquely, the guide tube 3 can be bent by rotating the hinge 5.

  Further, an operation wire hole 6 penetrating in the longitudinal direction is formed at a position where the dimension in the longitudinal direction of each cylinder 4 is the shortest. Further, an operation wire 7 is passed through the operation wire hole 6 so as to connect each cylinder 4.

  Further, in the vicinity of the tip of the guide tube 3, the angle of the end surface with respect to the center plane is changed so that the guide tube 3 bends at an angle (for example, 90 °) different from other portions. That is, by operating the operation wire 7, only the vicinity of the tip of the guide tube 3 is bent at a different angle from the other parts.

Next, the ultrasonic thickness measuring method of this embodiment will be described in order.
The ultrasonic thickness measuring method of the present invention is characterized in that a rail is laid in the header 51 in order to guide the guide tube 3, and in this embodiment, the roller chain 9 is used as the rail.

The ultrasonic thickness measuring method according to this embodiment includes a rail laying step P1, a guide tube fixing step P2, a guide tube moving step P3, and a guide tube bending step P4 in this order.
The rail laying step P1 is a step of laying the roller chain 9 so as to extend in the longitudinal direction of the header 51.
Specifically, as shown in FIG. 3, first, after the wire 10 is attached to the tip of the roller chain 9, the wire 10 is inserted from the first inspection hole 53, the wire 10 is pulled, and passes through the header 51. Then, it is pulled out from the second inspection hole 54. Although the space | interval of the 1st inspection hole 53 and the 2nd inspection hole 54 changes with plants, it is about 3 m, for example.

Next, as shown in FIG. 4, the roller chain 9 is connected and formed into an annular shape outside the header 51.
Specifically, first, the chain fixing member 11 is fixed to the first inspection hole 53 and the second inspection hole 54. As shown in FIG. 5, the chain fixing member 11 includes a rod-shaped member 12 and a pair of sprockets 13 provided at both ends of the rod-shaped member 12. When the chain fixing member 11 is fixed to the first inspection hole 53 and the second inspection hole 54, the rod-shaped member 12 is along the inner peripheral surface of the inspection holes 53 and 54, and the pair of chain fixing members 11 are connected to each other. It is fixed so that the distance of

  Next, the end portions of the roller chain 9 are connected so that the roller chain 9 forms an annular shape, and the roller chain 9 is hung on the four sprockets 13. At this time, by adjusting the position of the sprocket 13 fixed to the rod-shaped member 12, the roller chain 9 is adjusted so that an appropriate tension is applied.

  The guide tube fixing step P2 is a step of fixing the guide tube 3 to the roller chain 9. When fixing the guide tube 3 to the roller chain 9, an attachment member 21 (so-called conveyor chain) is fixed to a corresponding portion of the roller chain 9, and then the guide tube 3 is fixed via the attachment member 21.

  As shown in FIG. 6, the guide tube moving step P <b> 3 is a step of inserting the guide tube 3 into the header 51 by rotating the roller chain 9. After the insertion, the roller chain 9 is further rotated, and the tip of the guide tube 3 is moved to the desired boiler tube 52 position.

  As shown in FIGS. 7 and 8, the guide tube bending step P4 is a step of bending the tip of the guide tube. Specifically, by operating the operation wire 7, the distal end of the guide tube 3 is directed toward the boiler tube 52.

  Thereafter, the cable 30 is introduced into the boiler tube 52 by inserting the cable 30 into the guide tube 3. That is, for example, when the operator introduces the cable 30 into the guide tube 3 and sequentially feeds it into the guide tube 3, the cable 30 is guided to the guide tube 3 along the extending direction of the guide tube 3. And proceed. As a result, the tip of the cable 30 is introduced to a predetermined position in the boiler tube 52. In the process of winding the cable 30 from the position using the cable winding device 33 and moving the cable 30 backward in the boiler tube 52, the thickness of the boiler tube 52 is increased by the sensor probe 2 provided in the cable 30. Measurement is performed.

  As described above, the thickness data of the boiler tube 52 measured by the sensor probe 2 is transmitted to the data collection device 31 through the wiring integrally provided in the cable 30. Then, after the measurement of the thickness of the boiler tube 52 by the sensor probe 2 is finished, the cable 30 is pulled out from the boiler tube 52 and the guide tube 3. This completes the wall thickness measurement operation.

According to the above embodiment, the roller chain 9 that functions as a rail for guiding the guide tube is laid in the header 51, and the guide tube 3 is fixed to the roller chain 9. It can be securely fixed in the stopper 51. Further, since the guide tube 3 can be moved along the roller chain 9, the guide tube 3 can be easily aligned in the direction along the longitudinal direction of the header 51.

  Further, the guide tube 3 can be easily aligned in the direction along the longitudinal direction of the header 51 by operating and rotating the annularly connected roller chain 9 outside the inspection hole.

  Further, by applying tension to the roller chain 9 with the sprocket 13 that constitutes the chain fixing member 11, the roller chain 9 can be prevented from loosening, and the guide tube 3 can be aligned more smoothly.

  Further, since the tip of the guide tube 3 can be bent by operating the operation wire 7, the tip of the guide tube 3 can be bent in the direction of the boiler tube 52, and the sensor probe 2 can be made more smoothly. The tube 52 can be guided.

(Second embodiment)
Next, a second embodiment of the ultrasonic thickness measuring apparatus according to the present invention will be described in detail with reference to the drawings. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted. In this embodiment, the guide rail 15 is used as a rail.

As shown in FIGS. 9, 10, and 11, the guide rail 15 is obtained by connecting a plurality of guide rail pieces 14 to each other. Each guide rail piece 14 is attached to a base member 16 having a long plate shape, a guide rail body 17 having a long plate shape attached to one surface 16 a of the base member 16, and the other surface 16 b of the base member 16. And an electromagnet 18 having a long plate shape.
The guide rail 15 is adjusted so that its length is substantially the same as the distance between the first inspection hole 53 and the second inspection hole 54.

  The base member 16 has connection portions 19a and 19b formed at one end and the other end, and can be connected to each other. The connecting portions 19a and 19b are connected by connecting pins 19 extending along the one surface 16a and the other surface 16b of the base member 16 and perpendicular to the longitudinal direction of the base member 16, and adjacent base members. 16 can rotate around the connecting pin 19.

The long plate-shaped guide rail body 17 has a hexagonal shape in which the cross-sectional shape perpendicular to the longitudinal direction is long in the width direction of the guide rail body 17, and one end and the other end of the cross-section in the longitudinal direction Nagata) shape. That is, among the four surfaces connecting one surface and the other surface of the guide rail body 17, the acute angle mountain-shaped ridges 20 extending in the longitudinal direction of the guide rail body 17 are formed on two surfaces extending in the longitudinal direction. Is formed.
The apex angle of the ridges 20 is preferably about 70 °. Moreover, as a material of the guide rail main body 17, a heat-treated carbon alloy is suitable, for example.

  The electromagnet 18 has a long plate shape that is substantially the same shape as the guide rail body 17 except that no protrusions are formed. The electromagnets 18 are connected to each other by an electric cable (not shown) and can supply power.

As shown in FIG. 12, a carriage 22 can be attached to the guide rail 15.
The carriage 22 includes an attachment plate portion 23 and three traveling wheels 24.
The mounting plate portion 23 has a rectangular plate shape, and three traveling wheels 24 are rotatably supported. The running wheel 24 is composed of a bearing 25 and a support shaft 26 that are slidably in contact with the ridges 20 of the guide rail body 17. A V-shaped groove corresponding to the ridges 20 is formed on the outer periphery of the bearing 25. 25a is formed.

  The traveling wheel 24 is fixed to the mounting plate portion 23 so that the two traveling wheels 24 and the one traveling wheel 24 have a positional relationship such that the guide rail body 17 is sandwiched therebetween. A mounting hole is formed at a fixed location of the traveling wheel 24 of the mounting plate portion 23, and the traveling wheel 24 is fixed to the mounting hole by a nut 28 screwed into a male screw formed on the outer periphery of the support shaft 26. ing.

That is, the carriage 22 can move along the guide rail 15 by the bearing 25 of the traveling wheel 24 sandwiching the guide rail body 17 rotating on the ridge 20. A cart operation wire (not shown) is attached to the cart 22. The carriage operation wire is a wire extended along the guide rail 15, and the carriage 22 can be moved along the guide rail 15 by pulling the carriage operation wire.
The number of traveling wheels 24 is not limited to three. For example, four traveling wheels 24 may be provided so as to be arranged on both sides of the guide rail 15.

The ultrasonic thickness measuring method according to this embodiment includes a rail laying step P1, a guide tube fixing step P2, a guide tube moving step P3, and a guide tube bending step P4 in this order.
The rail laying step P <b> 1 of the present embodiment is a step of laying a plurality of guide rails 15 so as to extend in the longitudinal direction of the header 51.

  Specifically, first, as shown in FIG. 13, after attaching the wire 10 to the distal ends of the plurality of connected guide rails 15, the wire 10 is inserted from the first inspection hole 53, and the wire 10 is pulled. The inside of the header 51 is extended to the position of the second inspection hole 54. This step is performed with the carriage 22 attached to the guide rail 15. One end of a rod-shaped fixing member 27 is attached to the rear end of the guide rail 15.

Next, as shown in FIG. 14, the guide rail 15 is fixed at the positions of the first inspection hole 53 and the second inspection hole 54.
Specifically, after the rod-shaped fixing member 27 is attached to the tip of the guide rail 15, the fixing member 27 is fixed to the first inspection hole 53 and the second inspection hole 54.
Next, the electromagnet 18 is energized to attach the guide rail 15 to the inner peripheral surface of the header 51.

  The guide tube fixing step P2 is a step of fixing the guide tube 3 to the carriage 22 of the guide rail 15. When the guide tube 3 is fixed to the carriage 22 of the guide rail 15, the guide rail 15 is taken out of the inspection holes 53 and 54 using the fixing member 27. Specifically, as shown in FIG. 15, the guide tube 3 is fixed to the guide rail 15 using a U-shaped gripping tool 35 attached to the carriage 22. As shown in FIG. 16, the gripping tool 35 can be folded so as not to hinder the movement of the guide tube 3 when the sensor probe 2 is inserted into the boiler tube 52.

As shown in FIG. 17, the guide tube moving step P <b> 3 is a step of aligning the guide tube 3 in the header 51 by operating a carriage operation wire attached to the carriage 22. After the alignment, the tip of the guide tube 3 is bent in the same manner as in the first embodiment so that the tip of the guide tube 3 faces the boiler tube 52.
The method of moving the guide tube 3 is not limited to the wire operation, and a method of moving the carriage 22 by providing a drive source in the carriage 22 and driving the drive source by an operation such as remote control.

  A camera 29 for aligning the guide tube 3 can also be attached to the carriage 22. Furthermore, the carriage 22 can also be used as a support in the middle of the guide tube 3.

  According to the embodiment, the guide tube 3 can be easily aligned in the direction along the longitudinal direction of the header 51 by moving the carriage 22 slidably fixed along the guide rail 15. .

  Further, by fixing the guide rail 15 to the header 51 using the fixing member 27, it is possible to prevent the guide rail 15 from being loosened and to align the guide tube 3 more smoothly.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, a bellows-shaped guide tube or the like can be used as an alternative to the guide tube 3 used in the above embodiments.

DESCRIPTION OF SYMBOLS 1 ... Ultrasonic wall thickness measurement unit 2 ... Sensor probe 3 ... Guide tube 9 ... Roller chain (rail) 11 ... Chain fixing member 13 ... Sprocket 14 ... Guide rail piece 15 ... Guide rail 21 ... Mounting member 22 ... Bogie 30 ... Cable 51 ... Drawer 52 ... Boiler tube 53 ... First inspection hole 54 ... Second inspection hole

Claims (6)

A cable is inserted through a guide tube into a boiler tube connected to the header through an inspection hole formed in the header, and the meat of the boiler tube is measured by an ultrasonic measurement sensor probe provided on the cable. An ultrasonic thickness measurement method for measuring thickness,
A rail laying step of laying rails so as to extend in the longitudinal direction of the header;
A guide tube fixing step of fixing a tip of the guide tube to the rail;
A guide tube moving step of moving the guide tube along the rail, and an ultrasonic thickness measuring method. The rail is constituted by a roller chain connected in an annular shape outside the inspection hole,
The ultrasonic thickness measuring method according to claim 1, wherein the guide tube is connected to the roller chain via an attachment member connectable to the roller chain. The rail laying step
Inserting the roller chain from the first inspection hole and pulling it out from the second inspection hole via the header;
Connecting the roller chain outside the inspection hole and making it annular,
Providing a tension to the roller chain by arranging a plurality of sprockets inside the header,
The ultrasonic thickness measurement method according to claim 2, wherein the guide tube moving step moves the guide tube by rotating the roller chain. The rail is a guide rail composed of a plurality of guide rail pieces connected to each other;
It consists of a carriage that can be slidably attached to the guide rail,
The guide tube is attached to the guide rail via the carriage,
The ultrasonic wall thickness measuring method according to claim 1, wherein the guide tube moving step is performed by pulling the carriage with a wire. The rail laying step
Inserting the guide rail from the first inspection hole and extending the interior of the header to the position of the second inspection hole;
The ultrasonic thickness measurement method according to claim 4, further comprising a step of fixing the guide rail at positions of the first inspection hole and the second inspection hole. The guide tube is configured to be able to bend its tip by remote operation,
The ultrasonic wall thickness measuring method according to any one of claims 1 to 5, further comprising a guide tube bending step of bending the tip of the guide tube.

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