Pipelines can be inspected for possible degradation post-lining. While liners can protect a pipe’s inside diameter from corrosion, the outer diameter of the pipe may still be subject to corrosion damage from exposure to the soil and coating holidays.
The remote field eddy current technique (RFT) is suitable for inspecting pipelines that are lined with polyethylene, HDPE, cement mortar and fiber-reinforced polymer (FRP). RFT can inspect through up to one-inch of liner with high-precision and accuracy. The tools require no contact, are bi-directional and can be deployed with either a rope tether or can free-swim through up to 30 miles of pipeline. They have soft, rubber, wheeled centralizers which are the only parts that touch the liner – ensuring that the inspection process does no damage. Their sensitivity to internal and external corrosion pits is equal. They can report the exact axial and clock location of any pits as well as defect depth and length, giving you all the components needed to ensure a pipeline’s condition.
United Pipeline Systems offers these RFT inspection services through a partnership with Russell NDE Systems Inc. of Alberta, Canada.