Method and system for detecting and displaying defects in piping

• US 5,907,100 A
• Filed: 06/30/1997
• Issued: 05/25/1999
• Est. Priority Date: 06/30/1997
• Status: Expired due to Term

• Current Assignee: Gas Technology Institute
• Original Assignee: Gas Research Institute (GTI Energy)
• Inventors: Cook, Patrick
• Primary Examiner(s): Brock, Michael
• Assistant Examiner(s): MILLER, ROSE MARY
• Application Number:
  US08/885,367
• Time in Patent Office: 694 Days
• Field of Search: 73/643, 73/597, 73/598, 73/599, 73/600, 73/602, 73/609, 73/610, 73/611, 73/612, 73/613, 73/614, 73/615, 73/616, 73/620, 73/622, 73/624, 73/628, 73/625 , 73/644
• US Class Current: 73/602
• CPC Class Codes: G01N 2291/0421 Longitudinal waves
• CPC Class Codes: G01N 2291/0422 Shear waves, transverse waves, horizontally polarised waves
• CPC Class Codes: G01N 2291/2634 cylindrical from outside
• CPC Class Codes: G01N 2291/2636 cylindrical from inside
• CPC Class Codes: G01N 29/2412 using the magnetostrictive properties of the material to be examined, e.g. electromagnetic acoustic transducers [EMAT]; investigating the presence of flaws using eddy currents G01N27/90, magnetostrictive transducers B06B1/08, measuring magnetostrictive properties G01R33/18
• CPC Class Codes: G01N 29/38 by time filtering, e.g. using time gates
• CPC Class Codes: G01N 29/40 by amplitude filtering, e.g. by applying a threshold or by gain control
• CPC Class Codes: G01N 29/50 using auto-correlation techniques or cross-correlation techniques

Abstract

A detection and imaging system 10 is provided for locating defects in pipes using electromagnetic acoustical transducer (EMAT) sensors. The system includes an ultrasonic generator 22 (FIG. 2) configured to transmit a pulse signal to the EMAT transmitter 16 (FIG. 1). The transmitter 16, in turn, sends an ultrasonic wave through a pipe 13. The EMAT receiver 18 (FIG. 1) is configured to detect the transmitted ultrasonic signal 24 and receive a reflected ultrasonic signal that is reflected by a defect in the pipe. A processor is configured to generate a filter signal based upon the transmitted ultrasonic signal 24, to correlate the filter signal and the rejected ultrasonic signal to derive the location of the defect relative to the receiver, and to display the profile of the defect.

Claims

1. A detection system for locating defects in pipes using ultrasonic waves, comprising:

an ultrasonic generator configured to transmit an ultrasonic signal through a pipe, said ultrasonic generator configured to produce a linear chirp firing pulse and including a linear chirp coil adapted to receive said firing pulse and produce said transmitted ultrasonic signal therefrom;

an ultrasonic receiver configured to detect said transmitted ultrasonic signal and receive a reflected ultrasonic signal that is reflected by a defect in said pipe; and

a processing logic configured to generate a filter signal based upon said transmitted ultrasonic signal and configured to correlate said filter signal and said reflected ultrasonic signal to derive a location of said defect relative to said detector.

2. The system of claim 1, further comprising an indicator configured to indicate to a user said location of said defect.

3. The system of claim 1, wherein said generator and said detector are disposed on an external surface of said pipe.

4. The system of claim 1, wherein said generator and said detector are disposed on an internal surface of said pipe.

5. The system of claim 1, wherein said generator and said detector are disposed on opposite surfaces of said pipe.

6. The system of claim 1, wherein said generator and said detector are an electromagnetic acoustic transducer.

7. The system of claim 1, wherein said processing logic comprises:

digital sine and cosine filters based upon said transmitted ultrasonic signal.

8. The system of claim 2, wherein said indicator is a graphical computer interface.

9. A detection system for locating defects in pipes using ultrasonic waves, comprising:

an ultrasonic generator configured to transmit said ultrasonic signal through a pipe, said ultrasonic generator configured to produce a linear chirp firing pulse and including a linear chirp coil adapted to receive said firing pulse and produce said transmitted ultrasonic signal therefrom;

an ultrasonic receiver configured to detect said transmitted ultrasonic signal and receive a reflected ultrasonic signal that is reflected by said defect in said pipe;

a processing logic configured to generate a filter signal based upon said transmitted ultrasonic signal and configured to correlate said filter signal and said reflected ultrasonic signal to derive a location of said defect relative to said detector; and

said processing logic further configured to correlate said filter signal and said reflected ultrasonic signal to derive a profile of said defect.

10. A detection system for locating defects in pipes using ultrasonic waves, comprising:

an ultrasonic generating means for transmitting an ultrasonic signal through a pipe, said ultrasonic generating means configured to produce a linear chirp firing pulse and including a linear chirp coil adapted to receive said firing pulse and produce said transmitted ultrasonic signal therefrom;

a receiving means for receiving a reflected ultrasonic signal that is reflected by a defect in said pipe based upon said transmitted ultrasonic signal;

a signal processing means for processing said reflected ultrasonic signal to determine a correlation vector and a peak vector; and

an imaging means for displaying a two-dimensional gray image of said defect of said pipe based upon said correlation vector and said peak vector.

11. A detection method for locating defects in pipes using ultrasonic waves, comprising the steps of:

transmitting an ultrasonic signal through a pipe by means of an ultrasonic generator configured to produce a linear chirp firing pulse, said ultrasonic generator including a linear chirp coil adapted to receive said firing pulse and produce said transmitted ultrasonic signal therefrom;

receiving a reflected ultrasonic signal that is reflected by a defect in said pipe based upon said transmitted ultrasonic signal;

generating a filter signal based upon said transmitted ultrasonic signal;

correlating said filter signal and said reflected ultrasonic signal to derive a location of said defect relative to said detector; and

correlating said filter signal and said reflected ultrasonic signal to derive a profile of said defect.

12. The method of claim 11, further comprising the step of indicating via a user device said location of said defect.

13. The method of claim 11, further comprising the step of indicating via a user device said profile of said defect.

14. The method of claim 11, further comprising the steps of:

transmitting said transmitted ultrasonic signal from a first position outside said pipe; and

receiving said reflected signal from a second position outside said pipe wall.

15. The method of claim 11, further comprising the steps of:

transmitting said transmitted ultrasonic signal from a first position inside said pipe; and

receiving said reflected signal from a second position inside said pipe wall.

16. The method of claim 11, further comprising the steps of:

transmitting said transmitted ultrasonic signal from a first position inside said pipe; and

receiving said reflected signal from a second position outside said pipe wall.

17. The method of claim 11, further comprising the steps of:

transmitting said transmitted ultrasonic signal from a first position outside said pipe; and

receiving said reflected signal from a second position inside said pipe wall.

18. The method of claim 11, further comprising the steps of:

generating said transmitted ultrasonic signal with a transmit electromagnetic acoustic transducer; and

receiving said reflected ultrasonic signal with a receive electromagnetic acoustic transducer.

19. The method of claim 11, further comprising the step of displaying on a screen said location of said defect.

20. The method of claim 11, further comprising the step of displaying on said screen said profile of said defect.

21. A computer readable medium comprising a program for locating defects in pipes using ultrasonic waves, comprising:

means for producing linear chirp firing pulses for activating an ultrasonic generator including a linear chirp coil adapted to produce a transmitted ultrasonic signal from the linear chirp firing pulses;

means for generating filter signals based upon said transmitted ultrasonic signal;

means for correlating said filter signals and a reflected ultrasonic signal to derive a location of said defect; and

means for correlating said filter signals and said reflected ultrasonic signal to derive a profile of said defect.