Patent ID: 6904818

Claim:
A method of inspecting a pipe, comprising: (a) mounting an inspection unit to a frame and mounting to the inspection unit a first ultrasonic transducer for determining wall thickness of a pipe and second and third ultrasonic transducers axially spaced apart from each other relative to a longitudinal axis of the unit for inspecting weld volume defects; (b) inserting the unit with the first, second and third ultrasonic transducers mounted thereto into a pipe and conveying the unit along the pipe; (c) periodically causing the first ultrasonic transducer to emit an acoustical signal into a wall of the pipe and detecting a return acoustical signal from the pipe and thereby determining wall thickness of the pipe; and (d) positioning the unit in a position that places the second and third ultrasonic transducers on opposite sides of a weld that extends circumferentially around the pipe, then rotating the second and third ultrasonic transducers relative to the frame about the axis of the unit and simultaneously causing the second ultrasonic transducer to emit an acoustical signal into the weld and receiving a return acoustical signal with the third ultrasonic transducer, to determine if a volume of the weld has any defects.