Detection of Internal and External Pits from Outside of a Pipe with New Technology

In-line inspection tools are commonly used to detect and locate pitting on pipelines with high accuracy; however, after excavation it is not always known exactly where the pitted area is located. External coatings must be removed and the pipe cleaned down to bare metal with sand-blast or other techniques, so that supplemental NDT techniques can be employed to locate the pitting and confirm its dimensions prior to repairs.A new technology has been developed, with industry support, to locate pits through coatings and deposits. Pit depths and remaining wall thickness can be sized, and pitted areas can be mapped out. Where access is provided to the inside of the pipe, a second (internal) tool, using the same multi-channel technology, can be used to scan up to 100 meters from the access point.