Near Field Eddy Current Testing (NFT) Technology
PICA offers NFT tools to detect and quantify broken wires in embedded cylinder PCCP in its Standard NDT Service Solutions offering. The technique relies on a “transformer coupling” to induce an electric current in the wires, which is interrupted if the wires are broken.
PICA’s NFT tools have several advanced features not observed on tools used by competitors. During the electromagnetic (EM) inspection, PICA runs multiple frequencies simultaneously and employs several detectors on the NFT tool to increase resolution and accuracy of wire break data and provide our clients with a higher level of confidence in the inspection results.
APPLICATIONS
- NFT is available for dewatered pipe applications with minimum 20-inch diameter access openings.
- The technology is best for embedded cylinder PCCP with steel cylinder thickness less than 10 gauge (0.1345 inches).*
- NFT is used primarily in industries with larger diameter pipe, such as in the water, wastewater, and power industries.
*For PCCP steel cylinder thicker than 10 gauge and for lined cylinder PCCP, Remote Field Testing (RFT) will assess the condition of the steel cylinder and even identify stresses in the cylinder. This helps identify areas of concern in lieu of NFT, sometimes before the first wire break occurs
Large Diameter NFT Tools (36-inch to 120-inch)
CAPABILITIES
- Can be fitted with high-resolution CCTV and LiDAR.
- Tool is sensitive down to 5 continuous wire breaks.
- Multiple data sets provide good sensitivity and accurate wire break data.
- Tool components are modular, allowing the entire tool to be assembled inside the pipe.
- Electric drive wheel conveys the NFT through the pipe at approximately 45 fpm.
