Apparatus for inspecting a pipeline

• US 4,964,059 A
• Filed: 08/15/1988
• Issued: 10/16/1990
• Est. Priority Date: 08/21/1987
• Status: Expired due to Term

• Current Assignee: JFE Engineering Corporation (JFE Holdings Incorporated)
• Original Assignee: NKK Corporation (JFE Holdings Incorporated)
• Inventors: Murashita, Kikuji, Kobayashi, Motoi, Sugaya, Nobuyasu, Kondo, Munetaka
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): Cosimano, Edward R.
• Application Number:
  US07/232,494
• Time in Patent Office: 792 Days
• Field of Search: 73/598, 73/622, 73/623, 73/628, 324/229, 324/237, 324/240, 324/242, 364/507, 364/561, 364/563, 367/13
• US Class Current: 702/38
• CPC Class Codes: G01B 17/04 for measuring the deformation in a solid, e.g. by vibrating string
• CPC Class Codes: G01N 2291/02854 Length, thickness
• CPC Class Codes: G01N 2291/02872 Pressure
• CPC Class Codes: G01N 2291/0289 Internal structure, e.g. defects, grain size, texture
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/2636 cylindrical from inside
• CPC Class Codes: G01N 29/07 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 29/265 by moving the sensor relative to a stationary material

Abstract

An apparatus for inspecting a pipeline having a pig body which measures an inner shape and a wall thickness of a pipe body, travelling inside the pipe body, comprises: at least one distance measuring device for measuring a travelling distance of the pig body; a rotation angle gauge for measuring a rotation angle of the pig body round its center axis; a plurality of transducers for transmitting and receiving ultrasonic beams being arranged in the circumferential direction of the pig body and being confronted with the inner surface of the pipe body, which measures the inner shape and the wall thickness of the pipe body; a recorder of the pig body which stores measured data; a signal processing device for processing signals from the distance measuring device, the rotation angle gauge and the transducers; and a data processing device for analyzing the measured data stored in the recorder after the pig body has been taken out of the pipe body.

Claims

1. An apparatus for inspecting a pipeline having a pig body which measures an inner shape and a wall thickness of a pipe body, traveling inside the pipe body, comprising:

at least one distance measuring device for measuring a traveling distance of the pig body;

a rotation angle gauge for measuring a rotation angle of the pig body around its center axis;

a plurality of transducers for transmitting and receiving ultrasonic beams being arranged in the circumferential direction of the pig body and being confronted with the inner surface of the pipe body, for measuring the inner shape and the wall thickness of the pipe body;

a recorder associated with the pig body which stores measured data;

a signal processing device for processing signals from the distance measuring device, the rotation angle gauge and the transducers, wherein said signal processing device includes means for interpolating unknown data with obtained signals; and

a data processing device for analyzing the measured data stored in said recorder after the pig body has been taken out of the pipe body.

2. The apparatus for inspecting a pipeline of claim 1, wherein said signal processing device includes means for selecting input signals on the basis of predetermined threshold levels.

3. The apparatus for inspecting a pipeline of claim 1, wherein said signal processing device includes means for recording a period of time during which ultrasonic beams are transmitted from the transducers and the ultrasonic beams reflected from the inner surface and the outer surface of the pipe body are received by the transducers.

4. The apparatus for inspecting a pipeline of claim 1, which further comprises means for indicating the inner shape of the pipe body with a graphic representation or a drawing by analyzing the signals recorded an the recorder.

5. The apparatus for inspecting a pipeline of claim 1, wherein the pig body has a unified outer shell.

6. The apparatus for inspecting a pipeline of claim 1, wherein the recorder has means for cooling which comprises thermo-electric elements.

7. The apparatus for inspecting a pipeline of claim 1, wherein the transducers are arranged so that each interval of the scanning lines of the transducers can be from 5 to 20 mm.

8. The apparatus for inspecting a pipeline of claim 1, wherein the at least one distance measuring device includes a rotary distance measuring device.

9. The apparatus for inspecting a pipeline of claim 1, wherein the at least one distance measuring device includes a rotary distance measuring device and an eddy current distance measuring device when the at least one distance measuring device comprises two or more devices.

10. An apparatus for inspecting a pipeline having a pig body which measures an inner shape and a wall thickness of a pipe body, traveling inside the pipe body, comprising:

at least one distance measuring device for measuring a traveling distance of the pig body;

a rotation angle gauge for measuring a rotation angle of the pig body around its center axis;

a plurality of transducers for transmitting and receiving ultrasonic beams being arranged in the circumferential direction of the pig body and being confronted with an inner surface of the pipe body, for measuring the inner shape and the wall thickness of the pipe body;

a recorder associated with the pig body which stores measured data, said recorder having means for cooling which comprises thermo-electric elements;

signal processing device for processing signals from the distance measuring device, the rotation angle gauge and the transducers; and

a data processing device for analyzing the measured data stored in said recorder after the pig body has been taken out of the pipe body.

11. An apparatus for inspecting a pipeline having a pig body which measures an inner shape and a wall thickness of a pipe body, traveling inside the pipe body, comprising:

at least two distance measuring devices for measuring a traveling distance of the pig body, including at least a rotary distance measuring device and an eddy current distance measuring device;

a rotation angle gauge for measuring a rotation angle of the pig body around its center axis;

a plurality of transducer for transmitting and receiving ultrasonic beams being arranged in the circumferential direction of the pig body and being confronted with an inner surface of the pipe body, for measuring the inner shape and the wall thickness of the pipe body;

a recorder associated with the pig body which stores measured data;

a signal processing device for processing signals from the distance measuring devices, the rotation angle gauge and the

a data processing device for analyzing the measured data stored in said recorder after the pig body has been taken out of the pipe body.