JPH0434450Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a continuous pipe inner surface inspection device for continuously inspecting circumferential welds of pipes in pipelines by ultrasonic flaw detection.

[Prior art and its problems]

When inspecting welds in the circumferential direction of pipes in pipelines using angle angle flaw detection, the position of the weld is accurately detected and the distance between the weld and the angle probe is measured. Accurate understanding is required.

An eddy current sensor is generally used as a means for detecting the position of a welded portion. However, detection with an eddy current sensor uses electromagnetic discontinuity, so if there is insufficient penetration in the weld, the electromagnetic disturbances generated in that area will cause accurate welding. It is not possible to know the location of the part.

When inspecting welds in the inner circumferential direction of pipes in pipelines using angle angle flaw detection, it is necessary to accurately determine the distance between the weld and the angle probe. Nevertheless, conventionally,
There was a problem that this could not be detected with high precision.

[Purpose of invention]

Therefore, the purpose of this invention is to accurately measure the distance between the weld and the angle probe when inspecting the weld in the circumferential direction of a pipe in a pipeline using the angle angle flaw detection method. It is an object of the present invention to provide a continuous pipe inspection device that can accurately inspect welded parts.

[Summary of the idea]

This idea uses an ultrasonic surface wave probe to detect the position of the weld in the circumferential direction of the pipe, and an oblique probe to detect defects on the pipe inner surface in a pipe inspection pig that travels inside the pipe. It is characterized in that the tentacles are arranged at predetermined intervals in the tube axis direction.

[Structure of the idea]

Next, this invention will be explained with reference to the drawings. FIG. 1 is a schematic side view of the device of this invention. Inside the pipe 1, which is connected to each other by a circumferential weld 2, runs a pig 3 to which disk-shaped through-hole cups 4, 5 are attached at the front and rear of the pipe.

In the pig 3, a tire-shaped surface wave probe 6 and a tire-shaped bevel probe 7 are arranged in this order at regular intervals in the tube axis direction, and each in the circumferential direction of the pig 3.
It is attached by levers 6' and 7'. The surface wave probe 6 is in contact with the inner surface of the tube 1 by a lever 6', and the angle probe 7 is in contact with the inner surface of the tube 1 by a lever 7'.

FIG. 2 is a schematic side view showing an example of a tire-shaped probe, and FIG. 3 is a schematic longitudinal sectional view. As shown in the drawing, the tire-shaped probe has a shaft 8 as its center, an inner water chamber 9 containing water as an ultrasonic signal propagation medium, an outer rubber tire 10, and a tire-shaped probe attached to the shaft 8. It consists of a probe 11 that is 12 is an O-ring, and 13 is a seal packing. A vibrator 14 is provided within the probe 11 .

In this invention, the surface wave probe 6 and the angle probe 7 having the above-described configurations are attached to the pig 3 at a constant interval a, as shown in FIG.

In the inspection, first, the distance b from the position of the surface wave probe 6 to the defective part 2' in the welded part 2 of the pipe 1 is determined using the surface waves as indicated by the arrows from the surface wave probe 6. Since the distance a between the surface wave probe 6 and the angle probe 7 is known, the distance a between the distance a and the distance b from the position of the surface wave probe 6 to the defective part 2' of the welded part is From the difference, the distance c from the angle probe 7 to the defective portion 2' can be determined.

Since the position of the angle probe 7 is fixed with respect to the pig 3, the position of the pig 3 with respect to the pipeline length can be measured separately using a counter etc. The position of the welding defect detected by No. 7 can be easily known.

[Effect of idea]

As described above, according to the device of this invention, the surface wave probe and the angle probe are arranged at a predetermined interval in the pipe axis direction on the pig traveling inside the pipeline. , the distance between the weld in the circumferential direction of the pipe in the pipeline and the angle probe can be determined with high precision, and thereby the weld can be inspected continuously and accurately. Industrially advantageous effects are brought about.

[Brief explanation of the drawing]

Fig. 1 is a schematic side view of the device of this invention, Fig. 2 is a schematic side view showing an example of a tire-shaped probe, and Fig. 3 is a schematic side view of the device of this invention.
The figure is a schematic longitudinal sectional view, and FIG. 4 is an explanatory diagram showing the positional relationship between the surface wave probe and the angle probe in the device of this invention. In the figure, 1... pipe, 2... welded part, 3...
...Pig, 4, 5...Scraper cup, 6...
Surface wave probe, 7... Bevel probe, 8... Axis, 9
... Water chamber, 10 ... Rubber tire, 11 ... Probe, 12 ... O ring, 13 ... Seal packing, 14 ... Vibrator.

Claims (1)

[Scope of utility model registration request] The pipe inner surface inspection pig that travels inside the pipe is equipped with an ultrasonic surface wave probe to detect the position of the weld in the circumferential direction of the pipe, and an angle probe to detect defects on the pipe inner surface. A continuous tube inner surface inspection device, characterized in that the tube is disposed at predetermined intervals in the tube axis direction.