ILI tools exceeding their design speed collect inaccurate data
Inspecting the integrity of a gas pipeline with inline inspection tools such as MFL or UT pigs not always delivers the expected results:
The inspection pigs collect data with the required accuracy only up to their design travel speed. Data collected at higher travel speed does not show the pipeline's integrity with the desired resolution thus allowing for the possibility to oversee eventual dangerous developments.
ILI tool speed over inspected pipeline length
Depending on the kind of inspection pig used in a gas pipeline, up to 40% of the pipeline length is inspected at a travel speed above the pig's design speed. Accordingly the pipeline operator does not receive reliable integrity data for up to 40% of his pipeline!
Until today customers and authorities had to accept this high share of unreliable integrity data as no reliable speed control method was available on the market.