JP2010160030A - Non-destructive inspection jig - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-destructive inspection jig capable of easily performing reproducible non-destructive inspection ensuring a definite precision with respect to the flaw detection of the curvature part and rectilinear part of the bend part of piping having a small caliber in a short time. <P>SOLUTION: A piping fixing part 19 comes into contact with the outer peripheral surfaces of the straight pipe parts of the front and rear of the bend part 12 of piping to be fixed by a fixing member and a probe holder retaining part 22 for retaining a probe holder 21, on which a probe 20 is mounted, is supported on the slide surface 19a of the piping fixing part 19 in a slidable manner by a support part 23. Then, the guide rail 24 of a guide plate 25 guides the probe holder retaining part 22 along the slide surface of the support part 23 in the longitudinal direction of the curvature part and rectilinear part of the bend part 12 of the piping. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nondestructive inspection jig for mounting a probe and scanning the surface of an inspection object to inspect the inspection object from the outside.

  Piping such as a drain line of a power plant has a bend (bent portion) and changes the direction of the fluid flowing through the piping. The pipe bend easily undergoes internal thinning due to erosion / corrosion or the like, and when erosion / corrosion occurs and internal thinning proceeds, internal fluid may leak. Erosion-corrosion is a thinning phenomenon caused by the interaction between erosion due to mechanical action and corrosion due to chemical action, similar to corrosion fatigue. Erosion is a phenomenon in which a surface is mechanically damaged due to repeated collision of a fluid with a material, and a part of the surface is detached. Corrosion refers to all damage chemically received by erosion.

  In order to cope with such a thinning phenomenon caused by erosion / corrosion, thinning control is performed by measuring the wall thickness at a fixed point of the pipe using ultrasonic waves. It is difficult to obtain an accurate flaw detection result because of the curvature shape of the bend portion of the small diameter pipe. In particular, when the bend portion of the small-bore pipe is formed of a socket elbow, the socket elbow has a complicated external shape, and therefore, the fender is hardly flawed. In view of this, usually, the test results of the most recent straight pipe portion are substituted and the thinning of the bend portion is evaluated. Further, instead of the ultrasonic flaw detection, a radiation transmission test is performed.

  Here, as a means for flaw detection at the elbow of the pipe bend, a trajectory is set on the pipe including the elbow, the moving body is moved along this trajectory, and the flaw detection arm is moved in a direction crossing the trajectory of the moving body. There is one which is arranged and attached so as to be rotatable in a plane perpendicular to the surface to be inspected (see Patent Document 1). This flaw detection apparatus obtains the distance of the probe with reference to the weld line between the straight pipe of the pipe and the elbow, and performs flaw detection while specifying the flaw detection position of the elbow.

  In addition, a pair of fixtures are brought into contact with the outer peripheral surface of the pipe across the bend portion of the pipe, the pair of fixtures are fixed to the pipe with a fixing band, and a probe is attached at the fixed portion. The probe holder holding part holding the child holder is rotatably supported, and the probe holder holding part is rotated in the longitudinal direction and the circumferential direction of the bend part of the pipe, so that the bend part of the small diameter pipe is provided. On the other hand, there is one that can perform nondestructive inspection easily and in a short time (for example, see Patent Document 2).

JP-A 61-223510 JP 2007-212406 A

  However, in the inspection by the radiation transmission test (RT), after filming, the film is developed and evaluated, so in the detailed measurement when the filming is unclear or in the unlikely event that thinning has occurred, You must shoot again. Therefore, not only does it take time to evaluate, but also increases the burden on workers.

  Moreover, in the thing of patent document 1, since the apparatus structure is complicated and the position of a flaw detection arm must be measured, it is difficult to flaw the bend portion of a small-diameter pipe, and the flaw detection work takes time. .

  Moreover, in the thing of patent document 2, although the flaw detection of the bending part (curvature part) which has the curvature of the bend part of piping is possible, the flaw detection of the part (straight part) which does not have the curvature in the bend part of piping is possible. Can not. This is because the probe holder holding portion holding the probe is supported by the rotation support portion so as to be freely rotatable, and can be slid and scanned only in the range of 0 ° to 90 °. is there. Since the pipe bend portion may be thinned not only in a curvature portion having a curvature but also in a straight portion having no curvature, it is desirable that flaw detection of the straight portion in the bend portion of the pipe can be performed.

  An object of the present invention is to provide a nondestructive inspection treatment capable of easily performing a flaw detection of a curvature portion and a straight portion of a bend portion of a small-diameter pipe and performing a reproducible nondestructive inspection in a short time. Is to provide the ingredients.

  The non-destructive inspection jig according to the invention of claim 1 is a probe for attaching a probe to a pipe fixing portion that is in contact with an outer peripheral surface of a straight pipe portion before and after a pipe bend portion and fixed by a fixing member. A probe holder holding portion holding the probe holder, and a support portion that slidably supports the pipe fixing portion; and the probe holder holding portion that is attached to the pipe fixing portion along a sliding surface of the support portion. And a guide plate having a guide rail for guiding the portion in the longitudinal direction of the curved portion and the straight portion of the bend portion of the pipe.

  A nondestructive inspection jig according to a second aspect of the present invention is the probe of the first aspect, wherein the probe holder holding portion is capable of sliding and scanning the probe holder in the circumferential direction of the outer peripheral surface of the pipe. It is comprised so that the said probe holder may be hold | maintained so that it may become.

  According to the first aspect of the present invention, the probe holder holding portion holding the probe is guided by the guide rail of the guide plate in the longitudinal direction of the curved portion and the straight portion of the bent portion of the pipe. In addition to the curvature portion of the portion, flaw detection of the straight portion is also possible. If the non-destructive inspection jig is installed in the pipe, the position of the non-destructive inspection jig is fixed, and the probe holder is guided by the guide rail of the guide plate. In this range, flaw detection can be performed quickly, and in the inspection of high-dose piping at a nuclear power plant, etc., it is possible to reduce the exposure of workers.

  According to the invention of claim 2, the probe holder holding part holds the probe holder so that it can be slidably scanned in the circumferential direction of the outer peripheral surface of the pipe. Directional flaw detection can be performed easily.

The block diagram at the time of applying the nondestructive inspection jig concerning embodiment of this invention to a socket elbow. The structure figure of the socket elbow which is a test object of the nondestructive test | inspection in embodiment of this invention. The arrow line view seen from arrow A1 direction of FIG. The arrow view seen from the arrow B1 direction of FIG. The front view of the piping fixing | fixed part in embodiment of this invention. The front view of the guide plate in embodiment of this invention. Sectional drawing of a state with no defect in the bend part of the back side of the socket elbow which is a test object of the nondestructive inspection in embodiment of this invention. The data figure of the flaw detection image data of the test object which makes the position of the probe holder holding part in the cross-sectional position of FIG. 7 a variable.

  FIG. 1 is a configuration diagram when a nondestructive inspection jig according to an embodiment of the present invention is applied to a socket elbow, FIG. 2 is a structural diagram of a socket elbow to be inspected for nondestructive inspection, and FIG. The arrow view seen from the arrow A1 direction, FIG. 4 is the arrow view seen from the arrow B1 direction of FIG.

  In FIG. 2, it is assumed that the inspection object of the nondestructive inspection in the embodiment of the present invention is the socket elbow 11, and the inspection object part is the back side of the socket elbow 11. The socket elbow 11 has a bend portion 12 for changing the flow direction of fluid and a socket portion 13 for connecting to other piping, and the socket portion 13 and a straight pipe portion 14 of other piping are connected by a welded portion 15. Is done. The bend portion 12 of the socket elbow 11 has a curved portion (curvature portion) 16 having a curvature and a portion (straight portion) 17 having no curvature, and the curvature portion 16 and the straight portion 17 on the back side of the bend portion 12. Is the site to be examined. A non-destructive inspection is performed by scanning a probe described later in the longitudinal direction (arrow S1 direction) on the back side of the bend portion 12. Further, as shown in FIG. 4, a non-destructive inspection is performed by scanning a probe described later in the circumferential direction (arrow S2 direction) of the outer peripheral surface of the bend portion 12.

  As shown in FIG. 1, a nondestructive inspection jig 18 is attached to the outer periphery of the socket elbow 11. The nondestructive inspection jig 18 includes a pipe fixing portion 19 having grip portions 29 at both ends for fixing the nondestructive inspection jig 18 to the outer peripheral surface of the socket portion 13 of the socket elbow 11, and a probe 20. A probe holder holding part 22 for holding the attached probe holder 21, a support part 23 for slidably supporting the probe holder holding part 22 on the sliding surface 19a of the pipe fixing part 19, and a pipe fixing A guide plate 25 having a guide rail 24 for guiding the probe holder holding portion 22 along the sliding surface 19a of the portion 19 in the longitudinal direction of the curvature portion and the straight portion of the bend portion 12 of the socket elbow 11; Composed. A guide screw 28 protruding from the support portion 23 is inserted into the guide rail 24.

  The probe holder holding portion 22 is guided by the guide rail 24 of the guide plate 25 and moves in the longitudinal direction on the back side of the bend portion 12 (in the direction of arrow S1). At that time, the probe holder holding portion 22 moves to the probe holder holding portion 22. The attached support portion 23 slides on the sliding surface 19 a of the pipe fixing portion 19. As a result, the probe 20 of the probe holder 21 moves in contact with the curved portion and the linear portion on the back side of the bend portion 12, and flaw detection data is detected by the probe 20. The flaw detection data detected by the probe 20 is input to a signal processing device (not shown).

  An interlocking rod 30 that moves in conjunction with the movement of the guide screw 28 is attached to the guide screw 28, and the other end of the interlocking rod 30 is attached to the position detector 31. As a result, the position detector 31 detects the position of the probe holder holding portion 22 (the position of the probe 20). The position of the probe 20 detected by the position detector 31 is input to a signal processing device that inputs and processes the aforementioned flaw detection data. Thereby, the signal processing apparatus stores the flaw detection data to be inspected in association with the position of the probe holder holding unit 22 detected by the position detector 31.

  Next, as shown in FIG. 3, the probe holder holding portion 22 is formed in a sector shape, and a guide hole 26 is provided in the sector shape portion. The probe holder 21 is guided by the guide hole 26 of the probe holder holding portion 22, and sliding scanning is also possible in the circumferential direction (direction of arrow S <b> 2) of the outer peripheral surface of the bend portion 12 of the socket elbow 11. Yes. In this case, although not shown, a circumferential position detector for detecting the sliding position of the probe holder 21 is provided, and the circumferential position is input to the signal processing device and associated with the circumferential position. The flaw detection data to be inspected is stored.

  The pipe fixing portions 19 are provided on both sides of the fan-shaped probe holder holding portion 22 so as to sandwich the socket elbow 11, and the pipe fixing portions 19 slide the support portions 23 at both ends of the probe holder holding portion 22. It is supported by the moving surface 19a. Guide screws 28 are provided on the support portions 23 at both ends of the probe holder holding portion 22 and are inserted into the guide rails 24 of the guide plate 25 attached to the pipe fixing portion 19. As a result, the probe holder holding portion 22 is guided by the guide rail 24 and scanned in the longitudinal direction (arrow S1 direction) on the back side of the bend portion 12.

  Further, a fixing member 27 is provided in a portion of the pipe fixing portion 19 that contacts the socket elbow 11, and this fixing member 27 contacts the outer peripheral surface of the straight pipe portion before and after the bend portion 12 of the socket elbow 11. The pipe fixing part 19 is fixed to the socket elbow 11.

  FIG. 5 is a front view of the pipe fixing portion 19, and FIG. 6 is a front view of the guide plate 25. As shown in FIG. 5, gripping portions 29 are provided at both ends of the pipe fixing portion 19 for contacting and gripping the outer peripheral surface of the straight pipe portion before and after the bend portion 12 of the socket elbow 11. The fixing member 27 is attached to the socket elbow 11 side of the portion 29 (the back side in FIG. 5). The fixing member 27 is formed of, for example, an adsorbing member (a suction cup, a magnet, etc.), and is adsorbed and fixed to the socket elbow 11 by a fixing member 27 of a pair of pipe fixing portions 19 provided so as to sandwich the socket elbow 11. A sliding surface 19 a on which the support portion 23 of the probe holder holding portion 22 slides is formed in the pipe fixing portion 19.

  As shown in FIG. 6, attachment portions 32 that are attached to the pipe fixing portion 19 are provided at both ends of the guide plate 25, and a grip portion 29 of the pipe fixing portion 19 is attached to the back side of the attachment portion 32. The guide plate 25 is provided with a mounting portion 33 for mounting the guide rail 24 and the position detector 31.

  FIG. 7 is a cross-sectional view showing a state in which the bend portion 12 on the back side of the socket elbow 11 is not defective. FIG. 8 is a diagram of flaw detection data to be inspected with the position of the probe holder holding portion at the cross-sectional position in FIG. It is a data diagram. As shown in FIG. 7, the positions of the curvature portion 16 and the straight portion 17 on the back side of the bend portion 12 of the socket elbow 11 are as shown in FIG. 7 when the position of the curvature portion 16 is represented by 0 ° to 90 °. The position can be represented by -α ° and 90 ° + β °. FIG. 7 shows a case where α and β are 15 °.

  In the linear portion 17, the probe holder holding portion 22 is linearly slid on the sliding surface 19 a of the pipe fixing portion 19 in the range of −15 ° to 0 ° and 90 ° to 105 °. In this case, the probe holder holding part 22 is guided by the guide rail 24 of the guide plate 25 and slides linearly on the sliding surface 19 a of the pipe fixing part 19. Similarly, in the curvature portion 16, the probe holder holding portion 22 slides in an arc shape on the sliding surface 19 a of the pipe fixing portion 19 in the range of 0 ° to 90 °.

  The probe 20 held by the probe holder 21 of the probe holder holding part 22 has the probe holder holding part 22 on the sliding surface 19a of the pipe fixing part 19 from the position of -15 ° to 105 °. Accompanying the movement to the position, flaw detection data is detected in the range of −15 ° to 105 ° of the bend portion 12 of the socket elbow 11. The signal processing device associates the flaw detection data measured by the probe 20 with the flaw detection data to be inspected in correspondence with the position of the probe holder holding portion 22 detected by the position detector 31 as shown in FIG. Remember as.

  A curve L1 in FIG. 8 is a characteristic curve indicating the thickness h of the bend portion 12 at each rotation position (−15 ° position to 105 ° position) of the probe holder holding portion 22. At the −15 ° position, the thickness of the bend portion 12 is h1, at the 0 ° position the thickness h is h2, at the 45 ° position the thickness h is h3, and at the 90 ° position the thickness h is h4, At the 105 ° position, the thickness h is h5. As described above, when the bend portion 12 on the back side of the socket elbow 11 is healthy, the thickness of the center portion of the bend portion 12 is the thickest and the thickness h gradually decreases toward both ends. A characteristic curve of the thickness h of the bend portion 12 along the original shape is obtained. In the embodiment of the present invention, not only 0 ° to 90 ° at the position of the curvature portion 16 but also thicknesses in the range of −15 ° to 0 ° and 90 ° to 105 ° at the position of the linear portion 17 can be measured.

  In the above description, the case where the nondestructive inspection jig 18 is mounted on the bend portion 12 of the socket elbow 11 to detect the flaw has been described. Is also possible.

  According to the embodiment of the present invention, the probe holder 21 to which the probe 20 is attached is held by the probe holder holding part 22, and the probe holder holding part 22 is held by the guide rail 24 of the guide plate 25. In this way, since the guiding is performed in the longitudinal direction of the curved portion and the straight portion of the pipe bend portion 12, not only the curved portion of the bent portion 12 of the pipe but also the straight portion can be detected.

  Further, since the nondestructive inspection jig 18 is fixed to the pipe by the fixing member 27 of the pipe fixing portion 19, the position of the nondestructive inspection jig 18 is fixed. Therefore, the support part 23 of the probe holder holding part 22 guided by the guide rail 24 of the guide plate 25 can slide on the sliding surface 19a of the pipe fixing part 19 stably. As a result, flaw detection can be quickly performed in the range of the curved portion and the straight portion of the bend portion 12 of the pipe, and in the inspection of the high-dose pipe at a nuclear power plant or the like, it is possible to reduce the exposure amount of the worker. Further, since the probe holder holding part 22 can slide and scan the probe holder 21 also in the circumferential direction of the outer peripheral surface of the pipe, flaw detection can be performed over a wide range of the bend part 12 of the pipe.

DESCRIPTION OF SYMBOLS 11 ... Socket elbow, 12 ... Bend part, 13 ... Socket part, 14 ... Straight pipe part, 15 ... Welded part, 16 ... Curvature part, 17 ... Straight part, 18 ... Nondestructive inspection jig, 19 ... Pipe fixing part, DESCRIPTION OF SYMBOLS 20 ... Probe, 21 ... Probe holder, 22 ... Probe holder holding part, 23 ... Support part, 24 ... Guide rail, 25 ... Guide plate, 26 ... Guide hole, 27 ... Fixing member, 28 ... Guide Screws, 29 ... gripping part, 30 ... interlocking rod, 31 ... position detector, 32 ... mounting part, 33 ... mounting part

Claims (2)

A pipe fixing part that abuts the outer peripheral surface of the straight pipe part before and after the pipe bend part and is fixed by a fixing member;
A support unit that slidably supports a probe holder holding unit that holds a probe holder to which the probe is attached to the pipe fixing unit;
A guide having a guide rail attached to the pipe fixing part and for guiding the probe holder holding part along the sliding surface of the support part in the longitudinal direction of the curved part and the straight part of the bend part of the pipe. The board,
A nondestructive inspection jig characterized by comprising:   The probe holder holding portion is configured to hold the probe holder so that the probe holder can slide and scan in the circumferential direction of the outer peripheral surface of the pipe. The nondestructive inspection jig according to claim 1.

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