Abstract: Defects in a pipeline may be detected by an in-line inspection tool passing therethrough. However, as the tool travels through the pipeline, errors associated with certain onboard components may accumulate. These errors may reduce the accuracy with which the locations of detected defects can be determined. Accordingly, markers may be positioned at various locations along the pipeline. Each marker may include a radio receiver to receive signal transmitted by an in-line tool passing thereby and one or more magnetic flux detection systems that may detect a magnetic field emanating from the in-line tool. The radio receiver may include an antenna comprising two or more coils connected in series and positioned side-by-side. The flux detection system may include one or more flux concentrators to amplify the strength of the magnetic field.

Abstract: Defects in a pipeline may be detected by an in-line inspection tool passing therethrough. However, as the tool travels through the pipeline, errors associated with certain onboard components may accumulate. These errors may reduce the accuracy with which the locations of detected defects can be determined. Accordingly, markers may be positioned at various locations along the pipeline. Each marker may include a radio receiver to receive signal transmitted by an in-line tool passing thereby and one or more magnetic flux detection systems that may detect a magnetic field emanating from the in-line tool. The radio receiver may include an antenna comprising two or more coils connected in series and positioned side-by-side. The flux detection system may include one or more flux concentrators to amplify the strength of the magnetic field.

Abstract: An in-line inspection tool is disclosed for inspecting the wall of a pipeline while traveling therethrough. The in-line inspection tool may include a transmitter, a signal generator, one or more receivers, and a decoder. The signal generator may generate a pseudorandom signal, generate an inspection signal, and drive the transmitter with a convolution of the pseudorandom signal and the inspection signal. The transmitter may transmit the convoluted signal to the wall of the pipeline. One or more receivers may receive from the wall of the pipeline a received signal comprising at least one of the convoluted signal and a reflection of the convoluted signal. The decoder may identify the inspection signal within the received signal by cross correlating the received signal and the pseudorandom signal.

Abstract: The invention locates impaired sections of a pipeline, such as sections where the wall of the pipeline has been weakened or thinned. It provides a moveable device which passes through the pipeline and which has a first station. The moveable device has means to locate its position accurately. There is a second station, which is mounted either on the moveable device or in association with a fixed location on the pipeline wall. Either the first station or the second station has an acoustic or seismic pulse generator, and the other has a pulse receiver. The time taken for a pulse to travel from the pulse generator to the receiver is found to vary with the condition of the pipeline wall at the location where the moveable device is located at the time it receives (or sends) the pulse. The rate of change of velocity of the pulse as the device passes different locations in the pipeline is also found to vary with the condition of the pipeline wall at such location.

Abstract: Defects in a pipeline may be detected by an in-line inspection tool passing therethrough. However, as the tool travels through the pipeline, errors associated with certain onboard components may accumulate. These errors may reduce the accuracy with which the locations of detected defects can be determined. Accordingly, markers may be positioned at various locations along the pipeline. Each marker may include a radio receiver to receive signal transmitted by an in-line tool passing thereby and one or more magnetic flux detection systems that may detect a magnetic field emanating from the in-line tool. The radio receiver may include an antenna comprising two or more coils connected in series and positioned side-by-side. The flux detection system may include one or more flux concentrators to amplify the strength of the magnetic field.

Abstract: An in-line inspection tool is disclosed for inspecting the wall of a pipeline while traveling therethrough. The in-line inspection tool may include a transmitter, a signal generator, one or more receivers, and a decoder. The signal generator may generate a pseudorandom signal, generate an inspection signal, and drive the transmitter with a convolution of the pseudorandom signal and the inspection signal. The transmitter may transmit the convoluted signal to the wall of the pipeline. One or more receivers may receive from the wall of the pipeline a received signal comprising at least one of the convoluted signal and a reflection of the convoluted signal. The decoder may identify the inspection signal within the received signal by cross correlating the received signal and the pseudorandom signal.

Abstract: A sensor unit for use in sensing conditions in a pipeline comprises an untethered a ball-shaped surround adapted to roll along the interior surface of a pipeline, and instrument package within the ball-shaped surround. The package contains at least one magnetometer or accelerometer. Preferably, three magnetometers, arranged orthogonally, are present. Other sensors can also be present as required, such as an acoustic sensor to detect leaks and a temperature or chemical sensor. Recording means record the data acquired by the magnetometer(s) or accelerometer and the sensors, and optionally also record a timing trace.

Abstract: This invention uses an interferometric fiber optic sensor, particularly a Sagnac or Michelson interferometer, in a first fiber to monitor a sensing length of the first fiber and to detect disturbances. Signals indicating disturbances are classified as being of interest or not of interest, depending on predetermined criteria. Disturbances of interest can be, for example, the breaking of reinforcement wires in concrete pipe, the breaking of wires in suspension cables, a fire, a pipeline leak, or an intrusion. A location sensor system is used to determine the location of disturbances of interest, and to confirm the interferometer signal to reduce noise. The location sensor system is a fiber optic sensor, such as a phase OTDR sensor or a Brillouin effect sensor, which can detect the location of events it senses. It is present either in the first fiber or in a separate fiber laid adjacent the first fiber along its sensing length, as for example in the same optical cable.

Abstract: Discloses methods to perform magnetic testing of tensioning elements in a pre-stressed concrete cylinder, such as a pipe or water reservoir and testing apparatus. The apparatus includes magnetic flux production means and detector means disposed proximal to a surface of the cylinder in a plane in common with the magnetic flux production means that is orthogonal to an axis of the cylinder. The apparatus operates over a range of low frequency signals, for example, between 20 and 300 hertz or a pulse. Output of the inspection apparatus includes a signal and distance plot showing the results of testing a cylinder at one or more frequencies. In accordance with another method of analysis, a characteristic of the phase of the output over distance is plotted, including the phase or representations of the in-phase or quadrature components of the received signal in relation to the driving signal.

Abstract: Discloses methods to perform magnetic testing of tensioning elements in a pre-stressed concrete cylinder, such as a pipe or water reservoir and testing apparatus. The apparatus includes magnetic flux production means and detector means disposed proximal to a surface of the cylinder in a plane in common with the magnetic flux production means that is orthogonal to an axis of the cylinder. The apparatus operates over a range of low frequency signals, for example, between 20 and 300 hertz or a pulse. Output of the inspection apparatus includes a signal and distance plot showing the results of testing a cylinder at one or more frequencies. In accordance with another method of analysis, a characteristic of the phase of the output over distance is plotted, including the phase or representations of the in-phase or quadrature components of the received signal in relation to the driving signal.

Abstract: A clamp has two injection moulded tangs 1, 2 hinges together by a pin 3 and held closed by a wing nut 4 and a screw 5 having a cross-head 6. The tangs each have a tapered groove 7 running around inside them. In use, this groove engages flanges F on tubes T with a seal S therebetween to hold the tubes in sealing relationship with each other. The one tang 2 has a clevis 10 defined by two lugs 11. Each has an overhung recess 12 into which the cross-head 6 of the screw clips. A crossbar 14 connects the lugs remote from their tang, whereby the screw is limited in its angular displacement about the recesses 12, as shown in FIG. 3. The crossbar also stabilises the lugs against relative displacement under load when the nut is tightened. The other tang 1 has a part conical formation 21 on lugs 22 defining a clevis 23 similar to clevis 10. The nut has a complementary conical recess 24. Engagement of the formation 21 in the recess 24 restrains the lugs from separating under load as the nut is tightened.

Abstract: Discloses methods to perform magnetic testing of tensioning elements in a pre-stressed concrete cylinder, such as a pipe or water reservoir and testing apparatus. The apparatus includes magnetic flux production means and detector means disposed proximal to a surface of the cylinder in a plane in common with the magnetic flux production means that is orthogonal to an axis of the cylinder. The apparatus operates over a range of low frequency signals, for example, between 20 and 300 hertz or a pulse. Output of the inspection apparatus includes a signal and distance plot showing the results of testing a cylinder at one or more frequencies. In accordance with another method of analysis, a characteristic of the phase of the output over distance is plotted, including the phase or representations of the in-phase or quadrature components of the received signal in relation to the driving signal.

Abstract: A clamp has two injection moulded tangs 1, 2 hinges together by a pin 3 and held closed by a wing nut 4 and a screw 5 having a cross-head 6. The tangs each have a tapered groove 7 running around inside them. In use, this groove engages flanges F on tubes T with a seal S therebetween to hold the tubes in sealing relationship with each other. The one tang 2 has a clevis 10 defined by two lugs 11. Each has an overhung recess 12 into which the cross-head 6 of the screw clips. A crossbar 14 connects the lugs remote from their tang, whereby the screw is limited in its angular displacement about the recesses 12, as shown in FIG. 3. The crossbar also stabilizes the lugs against relative displacement under load when the nut is tightened. The other tang 1 has a part conical formation 21 on lugs 22 defining a clevis 23 similar to clevis 10. The nut has a complementary conical recess 24. Engagement of the formation 21 in the recess 24 restrains the lugs from separating under load as the nut is tightened.

Abstract: Method and apparatus for detecting failure of tensioned reinforcements in a structure by means of a plurality of acoustic or seismic detectors disposed about the structure in a known arrangement, processing signals from the detectors to determine frequency contents and origins, and identifying simultaneous signals as due to the failure of tensioned reinforcements in the structure when they meet spectral and origin criteria.

Abstract: An array of acoustic sensors spaced along a cable is deployed in a fluid filled concrete pipeline and the sensors are monitored to find acoustic anomalies, particularly anomalies resulting from breakage of a reinforcing wire for the concrete. The location of wire breaks is found from the data collected.