Device for the ultrasonic non-destructive testing of tubes

Claim 2

Ultrasonic device for non-destructive testing of tubes having a thickness which is small as compared with their diameter, comprising a head having a longitudinal axis and insertable into a tube along said longitudinal axis means for centering the head in a tube and means for imparting to the head a rectilinear motion along said longitudinal axis and a rotational motion about said axis, said head containing ultrasonic transducer means arranged to be coupled with a wall of a tube into which said head is introduced through a fluid and able to transmit an ultrasonic beam in a direction at an angle with said longitudinal axis and to detect echoes of said beam, wherein said transducer means comprise two first ultrasonic transducers located symmetrically with respect to a plane perpendicular to said axis and delivering a focussed base directed in a plane containing said longitudinal axis and at an angle with a direction perpendicular to the longitudinal axis, and two second ultrasonic transducers located symmetrically with respect to a plane perpendicular to said longitudinal axis and each delivering a focussed beam directed parallel to a line perpendicular to said longitudinal axis and located at a distance from said line whereby the beam is oblique with respect to the wall of a tube into which said head is introduced.

Claim 3

Device according to claim 1, wherein said two second ultrasonic transducers are offset along said axis by one half the distance over which said head is moved rectilinearly per turn of said rotational motion during said rectilinear motion.

Claim 4

Device according to claim 1, wherein said first and second ultrasonic transducers are so angularly located that the angle of the beam delivered by each one of said transducers in a tube wall is about 45° with respect to a line orthogonal to a tube wall.

Claim 5

Device according to claim 1, wherein said means for centering said head in said tube comprises a plurality of balls retained in said head, distributed at angular intervals about said longitudinal axis and by resilient pushing means biasing said balls in a direction radially outwardly of said head.

Claim 6

Ultrasonic device for non-destructive testing of tubes having a small thickness as compared with their diameter, comprising a head having a longitudinal axis and insertable into a tube along said longitudinal axis, means for centering the head in a tube and means for imparting to the head a rectilinear motion along said longitudinal axis and a rotational motion abut said axis, said head containing ultrasonic transducer means arranged to be coupled with a wall of a tube into which said head is introduced through a fluid and able to transmit an ultrasonic beam in the form of a volume waves in a direction at an angle with said longitudinal axis and to detect echoes of said beam, wherein said transducer means comprise at least one first ultrasonic transducer delivering a focussed beam directed in a plane containing said longitudinal axis and at an angle with a direction perpendicular to the longitudinal axis, and at least one second ultrasonic transducer delivering a focussed beam directed parallel to a line perpendicular to said longitudinal axis and located at a distance from said line whereby the beam is oblique with respect to the wall of a tube into which said head is introduced, wherein one at least of said first and second ultrasonic transducers is provided with a reflector for receiving an echo of said beam on an internal face of a tube wall and reflecting said echo toward the respective transducer, and wherein said head is operatively associated with a circuit having range gates for separating echoes due to internal faults and external faults in a tube into which said head is introduced, said gates being synchronized by a signal generated responsive to the echo from said reflector.

Claim 7

Ultrasonic device for non-destructive testing of tubes having a small thickness as compared with their diameter, comprising a head having a longitudinal axis and insertable into a tube along said longitudinal axis, means for centering the head in a tube and means for imparting to the head a rectilinear motion along said longitudinal axis and a rotational motion abut said axis, said head containing ultrasonic transducer means arranged to be coupled with a wall of a tube into which said head is introduced through a fluid and able to transmit an ultrasonic beam in the form of a volume waves in a direction at an angle with said longitudinal axis and to detect echoes of said beam, wherein said transducer means comprise at least one first ultrasonic transducer delivering a focussed beam directed in a plane containing said longitudinal axis and at an angle with a direction perpendicular to the longitudinal axis, and at least one second ultrasonic transducer delivering a focussed beam directed parallel to a line perpendicular to said longitudinal axis and located at a distance from said line whereby the beam is oblique with respect to the wall of a tube into which said head is introduced, wherein one at least of said first and second ultrasonic transducers is provided with a reflector for receiving an echo of said beam on an internal face of a tube wall and reflecting said echo toward the respective transducer, and wherein said head is operatively associated with a circuit having range gates for separating echoes due to internal faults and external faults in a tube into which said head is introduced, said gates being synchronized by a signal generated responsive to the echo from said reflector.