TDW introduces small diameter inspection tool

TDW has commercialised the 4 inch (102 mm) magnetic flux leakage (MFL), deformation and internal versus external discrimination tool.

The inline inspection (ILI) tool helps ensure pipeline integrity by detecting pitting and general corrosion as well as interacting features such as dents with metal loss.

It produces comprehensive metal loss and geometry data in a single run and its design ensures the tool performs within the optimal inspection velocity range, producing high quality survey results with reduced flow conditions.

The tool generally requires a minimum operating pressure of 20.7 bar, although it is capable of lower pipeline operating pressures and flows on a case-by-case basis, with TDW validating the reliability of the tool in liquid and gas at pressures as low as 13.78 bar. 

TDW Senior Product Manager Pipeline Integrity Tod Barker said that the tool can overcome some of the challenges in MFL inspections.

“ILI using MFL technology is one of the most common non-destructive inspection methods utilised for the detection of general and pitting corrosion in pipelines,” said Mr Barker.

“The difficulty associated with conventional 4 inch MFL designs is, to sufficiently saturate the pipe wall with magnetic flux, the brushes must be short and thick.

“This creates drag that makes it more difficult for the tool to traverse the pipeline at optimal velocity.

“Slowing down, speeding up and stops and starts can all negatively affect the quality of the inspection data.

“The 4 inch tool significantly reduces that risk.”

Mr Barker said that the ILI tool performed within the recommended speed of 3.05 m/s or less for 100 per cent of a recent low flow liquid pipeline inspection.

During tool development, testing covered more than 430 km of pipeline across more than 31 customer inspections.

For more information visit the TDW website.

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