Internal riser inspection device
First Claim
Patent Images
1. A method of inspecting a pipe, comprising:
- (a) mounting to a inspection unit a first ultrasonic transducer for determining wall thickness of a pipe and a second and third ultrasonic transducers for inspecting weld volume defects;
(b) inserting the unit into a pipe and conveying the unit along the pipe;
(c) periodically causing the first ultrasonic transducer to emit an acoustical signal into the pipe and detecting a return acoustical signal from the pipe to determine wall thickness; and
(d) positioning the unit in a position that places the first and second ultrasonic transducers on opposite sides of a weld, then 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.
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Abstract
An internal inspection unit for pipe has ultrasonic transducers that inspect weld volume, weld root, and wall thickness. The ultrasonic transducers are mounted to a portion of the inspection unit that is rotatable, but no more than one full revolution. One of the units has independently movable shoes for each separate transducer. The shoes are moved between retracted and extended positions by pneumatic cylinders. The other unit has shoes that support more than one transducer, the shoes being biased outwardly by springs.
90 Citations
26 Claims
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1. A method of inspecting a pipe, comprising:
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(a) mounting to a inspection unit a first ultrasonic transducer for determining wall thickness of a pipe and a second and third ultrasonic transducers for inspecting weld volume defects;
(b) inserting the unit into a pipe and conveying the unit along the pipe;
(c) periodically causing the first ultrasonic transducer to emit an acoustical signal into the pipe and detecting a return acoustical signal from the pipe to determine wall thickness; and
(d) positioning the unit in a position that places the first and second ultrasonic transducers on opposite sides of a weld, then 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. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of inspecting a pipe, comprising:
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(a) providing a self-propelled drive unit having a longitudinal axis;
(b) mounting an inspection unit on the drive unit for rotation about the longitudinal axis, the inspection unit having a first ultrasonic transducer for determining a wall thickness of a pipe, second and third ultrasonic transducers spaced axially from the first ultrasonic transducer for detecting any flaws in a volume of a weld, and third and fourth ultrasonic transducers for detecting flaws in a root of the weld, the third and fourth ultrasonic transducers being spaced the same axial distances from the first ultrasonic transducer as the second and third ultrasonic transducers, but circumferentially offset, each of the transducers being mounted to a separate shoe that is movable between a retracted position and an extended position;
(c) stopping the unit within the pipe in a position that places the second and third ultrasonic transducers on opposite sides of a weld and the fourth and fifth ultrasonic transducers on opposite sides of the weld, causing the shoes that contain the second through fifth ultrasonic transducers to contact an inner diameter of the pipe, then rotating the inspection unit less than one full revolution; and
(d) while rotating the inspection unit, causing the second ultrasonic transducer to emit an acoustical signal into the volume of the weld and receiving a return acoustical signal with the third ultrasonic transducer to inspect the volume of the weld; and
(e) at the same time as step (e), causing the fourth ultrasonic transducer to emit an acoustical signal that reflects into the root of the weld, and receiving with the fourth ultrasonic transducers any acoustical signals resulting from any defects in the root of the weld, and causing the fifth ultrasonic transducer to emit an acoustical signal that reflects into the root of the weld and receiving with the fifth ultrasonic transducer any acoustical signals resulting from any defects in the root of the weld; and
(f) moving the inspection unit linearly within the pipe, moving the shoe containing the first ultrasonic transducer to an extended position in contact with the inner diameter of the pipe and causing the first ultrasonic transducer to periodically emit an acoustical signal into the pipe and detecting a return acoustical signal to determine wall thickness. - View Dependent Claims (9, 10, 11, 12)
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13. An apparatus for inspecting pipe, comprising:
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an inspection unit having an axis;
a first ultrasonic transducer carried by the inspection unit for emitting and receiving acoustical signals to determine a wall thickness of the pipe;
second and third ultrasonic transducers carried by the inspection unit for emitting and receiving acoustical signals through a volume of a weld in the pipe;
fourth and fifth ultrasonic transducers carried by the inspection unit, each for emitting acoustical signals and receiving acoustical signals that pass through a root portion of the weld; and
the second through fifth ultrasonic transducers being mounted for selective rotation about the axis of the inspection unit no more than one full revolution. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. An apparatus for inspecting pipe, comprising:
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a frame having an axis and mounted on a set of drive wheels and a set of support wheels spaced axially from the drive wheels;
a linear drive motor mounted to the frame and coupled to the drive wheels for moving the frame linearly along an interior of a pipe;
an inspection unit mounted to the frame;
a radial drive motor for rotating the inspection unit relative to the frame about an axis of the frame;
a plurality of sets of shoes carried by the inspection unit and spaced circumferentially around the axis, each of the sets comprising at least two shoes spaced circumferentially apart from each other, the shoes within each of the sets being at the same axial position along the inspection unit, some of the sets being located at different axial positions from other of the sets;
a plurality of pneumatic cylinders, each mounted to one of the shoes of the inspection unit perpendicular to the axis;
at least one control valve coupled to the pneumatic cylinders for selectively moving the shoes radially outward to an extended position for engaging an inner diameter of the pipe and moving the shoes radially inward to a retracted position to facilitate entry of the inspection unit into the pipe;
a plurality of recesses in outer surfaces of the shoes;
a plurality of ultrasonic transducers mounted in the recesses for emitting and receiving acoustical pulses to determine a wall thickness of the pipe and detect defects in welds; and
a plurality of passages in the shoes for delivering a coupling liquid to the recesses. - View Dependent Claims (21, 22, 23)
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24. An apparatus for inspecting pipe, comprising:
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an elongated frame having an axis and mounted on at least two sets of wheels;
an inspection unit mounted to the frame intermediate forward and rearward ends of the frame, defining a forward frame portion and a rearward frame portion, with one of the sets of the wheels mounted to the forward portion and the other of the sets of wheels mounted to the rearward portion;
a radial drive motor for rotating the inspection unit relative to the frame about an axis of the frame;
a plurality of shoes spaced circumferentially around the axis, each of the shoes being elongated in a axial direction and urged radially outward relative to the inspection unit;
a plurality of recesses in an outer surface of each of the shoes;
a plurality of ultrasonic transducers mounted in the recesses for emitting and receiving acoustical pulses to determine a wall thickness of the pipe and detect defects in welds; and
a plurality of passages in the shoes for delivering a coupling liquid to the recesses. - View Dependent Claims (25, 26)
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Specification