RFT tools inspect metallic pipes for corrosion through internal liners and scale. The technique is ideally suited to inspect pipes with internal liners (such as cement mortar, HDPE, coal tar epoxy, and other liners), but it can also be deployed on unlined pipes. Properly implemented RFT employs many detectors (sometimes hundreds) around the circumference to create detailed corrosion maps of the metal cylinder. The technique is well suited for cast iron pipe, ductile iron pipe, steel pipe, concrete cylinder (bar-wrapped) pipe, reinforced concrete cylinder pipe, and prestressed concrete cylinder pipe (PCCP). Detailed mapping of the cylinder also provides insight on the construction style (e.g., spiral welded vs. seam welded) and cylinder stresses, in addition to both internal and external localized corrosion. It is called “remote field” because the exciter and detectors are spaced at least 2.5 pipe diameters apart. PICA’s Remote Field tools are also known as “See Snake” Tools.
- RFT is used in all industries served by PICA (water, wastewater, power, industrial, mining, and oil & gas).
- RFT is designed to be used on all metallic pipes, including nodular materials such as cast and ductile iron.
- RFT is also successfully used to inspect concrete pressure pipes containing a steel cylinder, such as C303 bar-wrapped (concrete cylinder) pipe, PCCP, and reinforce concrete cylinder pipe.
- Free-swimming RFT tools can be launched in fully operational pipes up to 42-inch diameter.
- RFT tools for dewatered applications in pipe sizes from 36-inch to 84-inch are winched between access openings.
Mid-Size (16-inch to 30-inch)
- Articulated mechanical design provides flexibility to navigate elbows.
- The diameter of each tool is slightly smaller than the internal diameter of the pipe to allow for protrusions, lining, and scale. Centralizers maintain a uniform annulus between the tool and the pipe.
- Size-on-size access is required for tool insertion and retrieval.
- Depending on tool size and access availability, the tools can be directly loaded into the pipeline through a manhole, through a removed section of pipe, or through a launch barrel.
- If a tool can be deployed in free-swimming mode, it can travel long distances between access points.
- In dewatered pipe, tools can be tethered on both ends and winched through pipeline sections up to 6,000 feet.