In 2010, T.D. Williamson, Inc. (TDW) announced the debut of its patent pending Spiral Magnetic Flux Leakage (SMFL) inspection tool, the latest addition to its range of magnetic flux leakage inspection tools.
According to TDW, combined MFL and TFI capabilities offer unprecedented detection capability. Whereas traditional axial MFL technology detects volumetric pipeline anomalies, general corrosion and wide circumferential flaws, the new SMFL tool makes it possible to detect long, narrow defects in a pipe body and in long seam welds. Transverse field inspection (TFI) tools are designed to detect general corrosion, as well as long and narrow metal loss features.
“By combining the capabilities of the standard TFI tool with those of a conventional axial MFL system, the new SMFL tool fills a niche in the market for a system that combines inspection technologies,” said Enzo Dellesite, General Manager - Middle East Operations for TDW. “By doing so, operators can detect and characterize a much wider range of pipeline defects that simply was not possible until now,” he added.
The high resolution SMFL tool offers a number of benefits. For example, while TFI technology relies upon two magnetizers, the SMFL tool requires only one. As a result, the SMFL tool can be paired with MFL technology without having to extend the length of the tool to accommodate it. The ability to pair tools means that multiple datasets are generated in a single run.
TDW uses these datasets by overlaying them, which greatly enhances characterization of anomalies that are revealed during an inspection run. For example, recently TDW ran separate runs with each system in a 16-inch pipe with a .250 wall thickness. While the axial MFL tool did not detect an external axial gouge, data generated by the SMFL tool revealed an external gouge measuring six inches long x .25-inch wide x 40% deep.
With a sampling frequency of up to 750 samples per second, the SMFL tool has an operating pressure range of 300 to 2,000 psi (21 to 137.8 bar) and an in-line temperature range of 14 to 131°F (-10° to 55°C.) It has a minimum bend radius of 1.5D and can travel at up to 8.3 ft/second, making it an extremely adaptable and efficient inspection system.
The addition of the SMFL tool further extends TDW’s comprehensive pipeline inspection services, which features the recently launched 48-inch Gas Magnetic Flux Leakage (GMFL) inspection tool. This tool operates at a steady speed in spite of variations in gas pressure that tend to cause other tools to stall and surge as they move through a gas line.