JPS6142127Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention mainly relates to an adapter used in the water immersion angle 2 transmission type ultrasonic flaw detection method developed by the present inventors for aging deterioration inspection of austenitic cast steel heating pipes, and in particular, radial fissure etc. Provides an adapter for axial defect detection.

Conventionally, it has been almost impossible to perform ultrasonic flaw detection on austenitic heat-resistant cast heating tubes such as steam catalytic reforming heating tubes. That is, in the conventional ultrasonic flaw detection method for pipes, as described in Japanese Patent Publication No. 34-1700, the entire pipe to be inspected was submerged in water. Ultrasonic flaw detection of pipes was almost impossible to implement.

Further, as an ultrasonic flaw detection method using a partial water immersion method without submerging the entire pipe in water, for example, the method described in Japanese Patent Application Laid-Open No. 15190/1984 is known. However, since this partial immersion method forms a layer of water using a jet jet water column,
The method could not be used to inspect already installed heating pipes due to water splashing. The present inventors have developed a water immersion angle two-angle transmission type ultrasonic flaw detection method that can effectively inspect such heating tubes. This new ultrasonic flaw detection method is shown in Fig. 1 and briefly explained. A transmitting probe 3 and a receiving probe are placed at a predetermined angle and interval on the same circumference along the outer circumference of a pipe to be inspected 1 such as a heating pipe. The ultrasonic wave 5 is transmitted from the transmitting probe 3 through the wall thickness of the tube to be inspected along a straight line connecting two points A and B on the outer periphery of the tube, and the receiving probe 4 detects the transmitted echo. By receiving this, it is possible to detect axial gaps (radial fissures) within the wall thickness of the pipe to be inspected. in this case,
Transmission and reception of the ultrasonic waves 5 between the tube 1 to be inspected and each of the probes 3 and 4 is carried out by the water immersion method so as not to be affected by the surface properties of the tube 1 to be inspected, and by the bevel method. The sound waves 5 are incident on the inner peripheral surface of the tube to be inspected at an incident angle such that they are not reflected from the bottom surface but are transmitted straight through the wall thickness.
Therefore, the ultrasonic wave 5 that is incident on the tube to be inspected 1 from the transmitting probe 3 at an incident angle of i using the water immersion method is refracted at the refraction angle θ at the incident point A, and moves in a straight line within the wall thickness of the tube to be inspected. It transmits at a depth of d, and at the incident point B, the incident angle θ
is refracted at a refraction angle i, and then the receiving probe 4
If there is a defect in the tree direction indicated by reference numeral 6, it will be detected by the reception probe 4 as an attenuated transmitted echo, and the presence of the defect 6 can be detected.

The outline of the apparatus used in such a water immersion angle two-transmission ultrasonic flaw detection method is shown in Fig. 2 and explained. 1 is a tube to be inspected, 2 is a device that incorporates a transmitting probe 3 and a receiving probe 4. This is an adapter disposed along the pipe 1 to be inspected. In order to use the water immersion method, water is supplied from a water tank 7 via a pump 8 to a portion of the adapter 2 that corresponds to the ultrasonic path between the probes 3 and 4 and the pipe to be inspected 1, as will be described later. As shown, the water leaking through the pipe to be inspected 1 flows into the water receiver 9 disposed below the pipe to be inspected 1 and is discharged to the outside. There is no risk of water flowing into the heating furnace even if it is in the heated state. Ultrasonic transmitting and receiving probes 3 and 4 built into the adapter 2 above
are respectively connected to a flaw detector 10, and as shown in FIG. The height of the transmitted echo is recorded on the recorder 11.

By the way, in the above device, when the outer diameter and inner diameter of the tube to be inspected 1 are redacted, or when the flaw detection depth d is changed, as is clear from FIG. The distance must also be changed.
However, since this device detects flaws using a local water immersion method, a predetermined layer of water must be formed between the probes 3 and 4 and the surface of the tube 1 to be inspected. Therefore, when changing the distance between the probes 3 and 4, it is necessary to maintain a constant distance between the probes 3 and 4 from the surface of the tube 1 to be inspected. However, an adapter having such a function has not yet been devised.

Therefore, the present invention uses a water immersion method to form a layer of water only on the surface of the tube to be inspected and in a very limited space between the probe, without submerging the entire tube to be inspected. It is an object of the present invention to provide an adapter in which a transmitting probe and a receiving probe can be attached to a sonic flaw detection device so as to be able to change their positions.

Therefore, the feature of the present invention is that the upper and lower hanging members 19 are connected by an arcuate angle 12 along the outer peripheral surface of the pipe 1 to be inspected, and an arcuate guide is attached to the angle 12 along the circumferential direction. A hole 13 is formed, and transmitting and receiving probe attachment blocks 14 are attached to the angle 12 via the guide hole 13 so that relative movement can be adjusted independently in the circumferential direction. , the transmitting probe 3 and the receiving probe 4 are respectively attached, and the inner circumferential surface of each block 14 on the side of the tube to be inspected 1 is slid along and onto the outer circumferential surface of the tube to be inspected 1. A hollow portion 16 is formed in each block 14 as a contacting curved surface that reaches from the inner peripheral surface to each probe 3, 4, and water is poured into the hollow portion 16 of each block 14 to fill the hollow portion 16 with water. and each block 14
A water supply port 17 for filling the gap between the inner circumferential surface of the tube 1 and the outer circumferential surface of the tube 1 to be inspected with water is formed respectively.

The embodiment shown in FIGS. 3 to 5 will be described below. The figure shows the adapter 2 attached to the tube to be inspected 1. In the figure, 12 is formed in an arc shape along the tube to be inspected 1, and has a pair of upper and lower guide holes 13 provided on both left and right sides. It's an angle. Reference numeral 14 denotes a pair of left and right probe built-in blocks into which the transmitting probe 3 or the receiving probe 4 is fitted and attached from the outside at a predetermined angle, and screw holes are provided at predetermined positions on the upper and lower surfaces. It is clamped and fixed between the upper and lower angles 12 by screwing together a fixing screw 15 through the guide hole 13 of the angle 12. The inner surface of the block 14 that comes into contact with the tube to be inspected 1 is formed into a concave surface along the outer circumferential surface of the tube to be inspected, and the tube to be inspected of each of the probes 3 and 4 built-in to perform the water immersion method. A hollow portion 16 is formed that opens from the opposing surface to the inner surface of the block, and water is injected into the hollow portion 16 from the water supply port 17 communicating with the hollow portion 16 as described above, and the inner surface of the block and the inspected object are injected with water. Even if water leaks from the gap with the pipe 1, the hollow part 1
6 is constantly filled with water.
Water leaking from inside the block 14 is discharged by the water receiver 9 as described above. Here, reference numeral 18 in the figure is a member for preventing the probes 3 and 4 from coming off, and reference numeral 19 is a hanging member for operating the adapter.

In the adapter 2 having the above configuration, each of the probes 3 and 4 is integrated with the block 14, and the inner surface of the block is brought into sliding contact with the tube to be inspected 1, and the adapter 2 is rotated around the tube to be inspected 1. Also, each probe 3, 4 is held at a constant angle with respect to the tube 1 to be inspected. Therefore, if the distance between the probes 3 and 4 on the same circumference is adjusted, the transmitted echo of the ultrasonic wave passing through the wall thickness of the tube to be inspected will be received by the receiving probe 4 as shown in FIG. In the above case, the distance between the probes 3 and 4 can be freely adjusted by loosening the fixing screw 15 and moving each probe 3 and 4 in the circumferential direction together with the block 14.
The probes 3 and 4 can be placed at the best reception position. By scanning the adapter 2 with the probes 3 and 4 arranged at predetermined positions along the tube 1 to be inspected, defects in the axial direction can be clearly detected.

In addition, the adapter 2 can also be used in welded parts where the outer diameter of the pipe 1 to be inspected changes or in pipes 1 to be inspected with different outer diameters.
is applicable. That is, when the outer diameter of the tube to be inspected 1 changes, the angle of the probes 3 and 4 with respect to the tube to be inspected 1 changes, and if the distance between the probes 3 and 4 is fixed, a transmitted echo will be transmitted to the receiving probe 4. However, if the probe spacing can be adjusted on the same circumference as described above, the probe 3,
This can be done by adjusting the 4 intervals. In this case, if the outside diameters of the tubes 1 to be inspected are extremely different, the connection between the inner surface of the block and the tube 1 to be inspected will be poor, making inspection impossible. It is necessary to replace it with.

Furthermore, if the retainers 18 of the probes 3 and 4 are removed from the adapter 2 and those having different angles with respect to the tube to be inspected 1 are attached, each probe 3,
4 can be adjusted on the same circumference, so the depth of flaw detection within the wall thickness of the tube to be inspected can be adjusted by changing the ultrasonic incident angle, and even if the wall thickness of the tube to be inspected 1 changes, flaw detection can be performed. It is possible.

In this way, the adapter of the present invention is used for detecting axial defects in the water immersion angle two-angle transmission type ultrasonic flaw detection method of pipes, and the transmitting probe and receiving probe can be moved on the same circumference. Because of this, it has excellent functions as mentioned above, and if you use this adapter to perform ultrasonic flaw detection on pipes such as austenitic cast steel heating pipes, it will be easier and faster to qualify than conventional destructive testing. The industrial effect of this method is significant because pipes can be inspected. In addition, the inner circumferential surface of the transmitting and receiving probe mounting blocks on the tube side to be inspected is a curved surface that runs along the outer circumferential surface of the tube to be inspected and slides into contact with the outer circumferential surface of the tube to be inspected. Leakage of water interposed between the pipe and the outer peripheral surface of the pipe to be inspected can be minimized.

Also, during inspection, by sliding the inner circumferential surface of each block along the outer circumferential surface of the tube to be inspected in the circumferential and axial directions, the distance between each probe and the outer circumferential surface of the tube to be inspected can be kept constant. The adapter can be easily and efficiently moved in the circumferential and axial directions with respect to the pipe under test while maintaining the same state, and the ultrasonic flaw detection using the local water immersion method of the pipe under test can be carried out easily and effectively. Even when the adapter is moved, leakage of water interposed between each probe and the outer peripheral surface of the tube to be inspected can be minimized.

Further, even when changing the distance between the probes, the distance between each probe and the outer circumferential surface of the tube to be inspected can be easily changed by keeping it constant.

In addition, each block was provided with a water supply port that injected water into the hollow part and filled the hollow part with water, and also filled the gap between the inner circumferential surface of each block and the outer circumferential surface of the pipe to be inspected. By connecting the flexible water supply hoses of the water supply device to the water supply ports, there will be no problem even when the adapter is moved relative to the pipe under test or when the distance between each probe is changed. Water can be supplied to the necessary parts such as departments.

[Brief explanation of the drawing]

Figure 1 explains the principle of the present invention, Figure 2 is a schematic diagram showing an example of the device used in the invention, Figures 3 and 4.
The figures are a front and plan view of the adapter according to the present invention, and FIG. 5 is a sectional view taken along line AA in FIG. 4. 1...Tube to be inspected, 2...Adapter, 3...Sending probe, 4...Receiving probe.

Claims (1)

[Scope of utility model registration request] The upper and lower hanging hand members 19 are connected to the arc-shaped angle 12 along the outer peripheral surface of the pipe 1 to be inspected, and the angle 12
An arc-shaped guide hole 13 along the circumferential direction is formed in the angle 12, and the transmitting and receiving probe mounting blocks 14 can be independently adjusted relative to each other in the circumferential direction via the guide hole 13. The transmitting probe 3 and the receiving probe 4 are respectively attached to each block 14, and the inner circumferential surface of each block 14 on the tube 1 side to be inspected is connected to the tube 1 to be inspected. Each block 14 has a curved surface along the outer peripheral surface of the block 14 and in sliding contact with the outer peripheral surface.
First, a hollow part 16 is formed that reaches each probe 3 and 4 from the inner peripheral surface, and water is poured into the hollow part 16 of each block 14 to fill the hollow part 16 with water. An adapter for ultrasonic flaw detection using a local water immersion method of a pipe, characterized in that a water supply port 17 is formed for filling the gap between the surface and the outer peripheral surface of the pipe 1 to be inspected with water.