In-Line Inspection Frequency for Transmission Pipelines

[Metcorr]

Hi All,

Hope all are well and safe.

I am seeking inputs from colleagues on the frequency of Inline Inspection (ILI) runs for transmissions pipelines. Currently we have a time-based frequency of 5-years for each technology such as (i) MFL, (ii) Crack, (iii), IMU and (iv) Caliper. We are wondering what is usual frequency of ILI runs in your experiences and is there any guideline to decide between time-based frequency and risk or condition-based frequency for Inline Inspection (ILI).

Any feedback, experience and available literature would be greatly welcomed.

Best regards,
Habiby

 

[1503-44]

5 Years is a typical starting point, however under pipeline integrity principles that 5 yr period can vary considerably with necessity according to the type, previous performance, pipe segment location and condition of any particular pipeline.

For documentation you can start with US CFR Title 49 Part 192 for gas pipelines and also Part 194 for liquid pipelines. In Part 192 you may want to refer to PP 150, 305, 612, 927, 931, 939, Table E II 2, and 941 among others. You will also probably want to review ASME B318 including Part S and B31.4 for liquid pipelines.

There are tons of both free and pay articles on assesment of pipeline integrity available on the internet, especially from free copies of pipeline industry magazines and other research papers. Google it.

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"

 

[gerhardl]

Any inspection must be done not less often than relevant local/national rules requires, and with increased frequency if experience says so,or cost of downtime,repair and cost of faults are higher than normal Other than purely mechanical considerations will influence frequency: Ringline (double) or single line? Availability of spares and repair if failure risk? important for a single factory or for a larger environment?

 

[Metcorr]

Hi ax1e.

Thanks for the inputs. Appreciated.

Best regards,
Habiby

 

[Metcorr]

Hi Gerhardl,

Thanks for your inputs. Appreciated.

Best regards,
Habiby