Westinghouse Electric Corporation

Clark B Candee

Gregory L Calhoun

David M Evans

An improved tube cutting apparatus and method for cutting through the inside of a metallic tube is disclosed herein. The apparatus generally comprises a support assembly which is slidably insertable within a tube, a flail tube cutting head connected to a short flexible shaft, and a linking shaft rotatably mounted within the support assembly for connecting the short flexible shaft of the cutting head to a longer flexible drive shaft. The center portion of the housing includes a mandrel circumscribed by a selectively expandable resilient bladder for temporarily affixing the support assembly to the inner wall of the tube in order to position the circular blade of the cutting head adjacent to a desired point along the longitudinal axis of the tube. The proximal and distal portions of the linking shaft include coupling assemblies for facilitating blade changes. In order to confine the cutting action of the blade on the cutting head to a thin circle around the inner wall of the tube, the support assembly also includes a thrust bearing that prevents the blade from moving longitudinally during the cutting operation.

Tube cutting apparatus and method

A sludge lance nozzle for removing sludge from between the tubes of a nuclear steam generator includes positioning apparatus mounted on top of the nozzle. The positioning apparatus includes a cylindrical eddy-current sensor mounted inside a cup-shaped non-magnetic electrically insulating spacer, which is in turn mounted in a cup-shaped support member fixedly secured to the nozzle. The tubes are arranged in rows and columns with the axes of the tubes in each column lying in a common column plane. The nozzle is moved perpendicular to the column planes close to one of the rows of tubes. The sensor produces a maximum-amplitude output signal when the sensing axis is coplanar with the column plane of a tube in the closest row of tubes and a minimum-amplitude output signal when the sensing axis is midway between adjacent tubes in the closest row of tubes.

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Edgewood, PA, United States of America

Clark B Candee