Westinghouse Electric Corporation

Francis X Gradich

Lee W Burtner

William G Clark, Jr

Michael J Metala

Charles H Roth, Jr

David A Chizmar

Warren R Junker

William E Pirl

William K Cullen

Annette M Costlow

Edward A Ray

Lawrence Galata

Stephen D Brown

Both a system and a method are provided which allows an eddy current probe to accurately determine both the proximity and dimensions of non-conductive structures which are normally invisible to such probes. The system comprises a portable target medium that is movable into a known position with respect to the non-conductive structure, and that includes a conductive material that couples strongly with a fluctuating magnetic field, and a movable eddy current probe that emanates a fluctuating magnetic field and which generates a signal indicative of the magnitude of the interaction between the field and the portable target medium from which the distance between the two may be computed. The system may be used to determine the proximity of non-conductive structures such as plastic pipes that have been buried under ground, as well as the dimensions of such non-conductive structures. When the system is applied to measure the dimensions of such a structure, the portable target medium assumes a form that is flexibly conformable to one of the walls of the structure and which is placed in abutting relationship thereto. The eddy current probe is then scanned against an opposing wall of the structure, whereby the width of the structure may be computed by measuring the strength of the interaction between the probe and the medium. In addition to measuring the dimensions of non-conductive structures, the system may be used to measure the dimensions of non-magnetic structures when the target medium includes a strongly magnetic material.

System and method using portable wall engaging ferromagnetic particle

Both a system and a method are provided which allows an eddy current probe to accurately determine both the proximity and dimensions of non-conductive structures which are normally invisible to such probes. The system includes a portable target medium that is movable into a known position with respect to the non-conductive structure, and that includes a conductive material that couples strongly with a fluctuating magnetic field, and a movable eddy current probe that emanates a fluctuating magnetic field and which generates a signal indicative of the magnitude of the interaction between the field and the portable target medium from which the distance between the two may be computed. The system may be used to determine the proximity of non-conductive structures such as plastic pipes that have been buried under ground, as well as the dimensions of such non conductive structures.

System and method including a buried flexible sheet target impregnated

System for inspecting the interior of tube plugs, particularly tube plugs of the type having expander elements disposed therein. The system includes a probe assembly connectable to the tube plug, the probe assembly having a rotatable and translatable probe carrier housing for housing a sensor probe capable of inspecting the tube plug. The probe assembly also includes a leaf spring extending through the probe carrier housing and attached to the sensor probe for radially outwardly biasing the sensor probe into sensing contact with the interior of the tube plug, particularly the interior of the tube plug located between the top of the tube plug and the expander element. A tangle-free flexible hose is connected at one end thereof to the probe carrier housing for transversely rotating and longitudinally translating the probe carrier housing. The flexible hose is also connected at the other end thereof to a probe driver assembly that rotates the flexible hose which in turn rotates the probe carrier housing. Rotation of the probe carrier housing rotatably translates the probe carrier housing into the tube plug for inspecting the tube plug in a helical scanning pattern.

Tube plug inspection system

An apparatus and a method for remotely inspecting the interior walls of a cavity having a circular cross section that varies in diameter, such as the interior of a hollow tube plug. The apparatus has an eddy current probe head having a distal and proximal end, wherein the distal end engages the cavity walls, an elongated support assembly connected to the proximal end of the probe that is insertable within the cavity, a radial extender mechanism for radially extending and withdrawing the distal end of the probe with respect to the longitudinal axis of the support assembly, and a probe driving and delivery system for inserting the support assembly into the cavity and helically moving the probe head to inspect the cavity walls for discontinuities. In the method of the invention, the radial extender mechanism radially retracts the probe head within the support assembly when it is inserted through the cavity prior to the inspection operation in order to avoid mechanical interference, and then radially extends the probe head into engagement with the cavity walls. The probe driving and delivery system then helically moves the probe head across the cavity walls to scan the walls for discontinuities that indicate cracks.

System and method for inspecting metallic plugs in heat exchanger tubes

Both an apparatus and method for accurately inspecting the profile of the inner wall of a conduit, such as a heat exchanger tube in a steam generator, is disclosed herein. The apparatus comprises a cylindrical probe body that is insertable within the tube, a probe assembly disposed within the probe body that includes an eddy current sensing coil and a copper plate which are movable with respect to one another, and a wall follower assembly including a stylus on one end and which is linked to the probe assembly on its other end for converting changes in the radius of the tube wall into changes in the distance between the eddy current sensing coil and the copper plate. A ferrite core is disposed within the sensing coil for focusing the electromagnetic flux into the copper plate. Additionally, the sensing coil is serially connected to a balancing coil in order to provide an accurate zero point for the sensing coil. In the preferred embodiment, the sensing coil is stationarily mounted within the probe body, while the copper plate is connected to the radially movable stylus assembly. The probe body and all of the components of the wall follower assembly including the springs which resiliently urge the stylus toward the tube wall are formed from nonconductive plastic materials so as to maximize the electromagnetic coupling between the eddy current sensing coil and the copper plate. The apparatus is capable of accurately detecting not only localized flaws within the inner tube wall, but also tube ovality and wall thinning which are typically caused by the deposition of sludge in the crevice regions of tubesheets and support plates of steam generators.

Apparatus and method for inspecting the profile of the inner wall of a

An optical inspection system for tubular products utilizes a feeler for engaging the internal surface of the tube to be inspected and a miniature charge coupled device video camera for viewing the interface between the feeler and the tube. An image processing computer responsive to the output of the video camera produces information for rapidly assessing damage or distortion of the tube. The camera is pulled or pushed through the tube while continuously monitoring the optical contrast between the feeler and the tube wall. The camera image of the tube ID is fed to the image processing computer to determine and record changes in ID contour is a function of the axial position of the camera and feeler. These data in turn can be used in tubing life prediction considerations. The data may be analyzed manually if desired.

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Elizabeth Township, PA, United States of America

Francis X Gradich