Method and apparatus for inspecting conduits

• US 5,591,912 A
• Filed: 03/10/1995
• Issued: 01/07/1997
• Est. Priority Date: 03/10/1995
• Status: Expired due to Fees

• Current Assignee: United States Department of Energy (Government of the United States of America)
• Original Assignee: United States Department of Energy (Government of the United States of America)
• Inventors: Spisak, Michael J., Nance, Roy A.
• Primary Examiner(s): Williams, Hezron E.
• Assistant Examiner(s): FAYYAZ, NASHMIYA SAQIB
• Application Number:
  US08/402,219
• Time in Patent Office: 669 Days
• Field of Search: 73/598, 73/600, 73/622, 73/623, 73/625, 73/628, 73/641, 73/629, 376/252, 376/249
• US Class Current: 73/623
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/103 one emitter, two or more receivers
• CPC Class Codes: G01N 2291/2636 cylindrical from inside
• CPC Class Codes: G01N 29/265 by moving the sensor relative to a stationary material

Abstract

An apparatus and method for ultrasonic inspection of a conduit are provided. The method involves directing a first ultrasonic pulse at a particular area of the conduit at a first angle, receiving the reflected sound from the first ultrasonic pulse, substantially simultaneously or subsequently in very close time proximity directing a second ultrasonic pulse at said area of the conduit from a substantially different angle than said first angle, receiving the reflected sound from the second ultrasonic pulse, and comparing the received sounds to determine if there is a defect in that area of the conduit. The apparatus of the invention is suitable for carrying out the above-described method. The method and apparatus of the present invention provide the ability to distinguish between sounds reflected by defects in a conduit and sounds reflected by harmless deposits associated with the conduit.

Claims

1. An ultrasonic inspection method of inspecting an area of a conduit to detect a defect or a deposit, which comprises the steps of:

a) positioning a probe inside said conduit, said probe comprising a pair of ultrasonic transceivers positioned on said probe such that said transceivers are on either side of and substantially equidistant from said area;

b) directing a first ultrasonic pulse, from a first transceiver of said pair, at said area of the conduit, from a first direction axially forward of said area; and

substantially simultaneously directing a second ultrasonic pulse, from a second transceiver of said pair, at said area of the conduit, from a second direction axially rearward of said area;

c) receiving at said first transceiver reflected sound signals caused by reflection of said first ultrasonic pulse from said area;

d) receiving at said second transceiver reflected sound signals caused by reflection of said second ultrasonic pulse from said area;

e) plotting said reflected sound signals versus time, wherein a defect is distinguished from a deposit and identified by observing overlap of signal patterns produced by both said transceivers, indicating that said reflected sound is received at the same time by both said transceivers.