0
Research Papers: NDE

Pipe Wall Damage Detection in Buried Pipes Using Guided Waves

[+] Author and Article Information
Rais Ahmad, Sourav Banerjee

Department of Civil Engineering and Engineering Mechanics, University of Arizona, Tucson, AZ 85721

Tribikram Kundu1

Department of Civil Engineering and Engineering Mechanics, University of Arizona, Tucson, AZ 85721tkundu@email.arizona.edu

1

Corresponding author.

J. Pressure Vessel Technol. 131(1), 011501 (Nov 25, 2008) (10 pages) doi:10.1115/1.3027460 History: Received February 26, 2007; Revised February 21, 2008; Published November 25, 2008

It is well known that cylindrical guided waves are very efficient for detecting pipe wall defects when pipes are open in the air. In this paper it is investigated how efficient the guided waves are for detecting pipe wall damage when the pipes are embedded in the soil. For this purpose guided waves were propagated through pipes that were buried in the soil by placing transmitters on one end of the embedded pipe and receivers on the other end. Received signals for both defect-free and defective pipes were recorded. Then the received signals were subjected to wavelet transforms. To investigate whether embedding the pipe in the soil makes it more difficult to detect the pipe wall defects, the same set of defective and defect-free pipes were studied before and after burying them in the soil. In both cases the defective pipes could be easily identified. Interestingly, contrary to the intuition, it was observed that under certain conditions defective pipes could be identified more easily in buried conditions. For example, the difference between the strengths of the initial parts of the received signal from defect-free and dented pipes was found to be greater for the buried pipes. Some qualitative justification for easier detection of buried dented pipes is provided.

FIGURES IN THIS ARTICLE
<>
Copyright © 2009 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Defect free (top) and defective (bottom three) steel pipes. All pipes are 1200mm(∼4ft) long with outer diameter 21.4mm and inner diameter (15.6mm). Defect dimensions are given in Table 1. All defects cover a complete (360deg) revolution.

Grahic Jump Location
Figure 2

Steel pipe embedded in soil, placed in a wooden box. Transmitter is on the left side and receiver on the right side.

Grahic Jump Location
Figure 3

Schematic of the pipe, transmitter and receiver—(a) free pipe and (b) embedded pipe. Transmitter on the left side is mounted on a plexiglas coupler that has a spherical outer surface and the receiver on the right side is in direct contact with the pipe.

Grahic Jump Location
Figure 4

Solid coupler with spherical outer surface, cylindrical inner surface, and conical side surface connects the transmitter and pipe. Incident beam striking the pipe at critical angle generates guided wave in the pipe wall.

Grahic Jump Location
Figure 5

Time histories for (a) defect-free pipe A, (b) gouged pipe B, (c) dented pipe C, and (d) removed metal pipe D when the pipes are open in the air, as shown in Fig. 3

Grahic Jump Location
Figure 6

Time histories for (a) defect-free pipe A, (b) gouged pipe B, (c) dented pipe C, and (d) removed metal pipe D, when the pipes are embedded in the soil, as shown in Figs.  23

Grahic Jump Location
Figure 7

Continuous wavelet transforms for a scale 1:16 using db4 wavelet function of the time histories for (a) defect-free pipe A, (b) gouged pipe B, (c) dented pipe C, and (d) removed metal pipe D when the pipes are open in the air, as shown in Fig. 3

Grahic Jump Location
Figure 8

Continuous wavelet transforms for a scale 1:16 using db4 wavelet function of the time histories for (a) defect-free pipe A, (b) gouged pipe B, (c) dented pipe C, and (d) removed metal pipe D when the pipes are embedded in the soil, as shown in Figs.  23

Grahic Jump Location
Figure 9

Continuous wavelet transforms for first 400 time divisions of the time history plots shown in Figs.  56 for a scale 1:16 using db4 wavelet function for defect-free pipes (top row), and dented pipes (bottom row), open in the air (left column), and buried in the soil (right column)

Grahic Jump Location
Figure 10

Reflected, transmitted, and leaky energies in different situations—defect-free ((a) and (b)) and defective pipes ((c) and (d)), pipes open in the air ((b) and (d)) and embedded in the soil ((a) and (c))

Grahic Jump Location
Figure 11

Gradation chart for soil particle size distribution

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In