pipeline corrosion monitoring

Buried Pipelines (external corrosion):

Buried pipelines usually receive two forms of external corrosion protection. A protective coating represents the primary form of protection, while cathodic protection (CP) is the secondary form. The CP system is designed to protect the external pipeline surface against corrosion at coating defects that are invariably present. The coating condition tends to deteriorate with time, leading to increased CP current requirements.

Various corrosion monitoring / inspection techniques are employed in the pipeline industry, such as test station potential readings, Close Interval Potential Surveys (CIPS), Direct Current Voltage Gradient Technique (DCVG), current mapping, corrosion coupons and in-line inspection tools.

Topical issues in modern pipeline corrosion monitoring/inspection programs include:

The use of the Global Positioning System (GPS).
Geographic information systems (GIS) to manage corrosion information.
Integration of corrosion data from various monitoring/inspection techniques.
Remote monitoring and wireless transmission of corrosion and CP data over long distances.
Stable, long-life reference electrodes and power supply for accomplishing the above.
The use of coupons to monitor the performance of CP systems.

References/Literature:

A.W. Peabody: "Control of Pipeline Corrosion", NACE International, Houston, 1967.

M.E. Parker and E.G. Peattie: "Pipeline Corrosion and Cathodic Protection, Third Edition.", Gulf Publishing, 1984.

NACE International and the Institute of Corrosion "Specialized Surveys for Buried Pipelines", Publication CEA 54277, Houston, 1990.

NACE International and the Institute of Corrosion "Cathodic Protection Monitoring for Buried Pipelines", Publication CEA 54276, Houston, 1990.

R.L. Pawson: "Close Interval Potential Surveys - Planning, Execution, Results", Materials Performance, February 1998, pp.16-21.

J.M. Leeds and J. Grapiglia: "The DC Voltage-Gradient Method for Accurate Delineation of Coating Defects on Buried Pipelines", Corrosion Prevention and Control, Volume 42, No. 4, 1995, pp.77-86.

K.M. Lawson and N.G. Thompson: "The Use of Coupons for Monitoring the Cathodic Protection of Buried Structures", Paper # 672, Corrosion 98, NACE International, San Diego, 1998.

M. Tullmin and J.W. Fourie: "GPS Technology in Pipeline Corrosion Control", Paper #8A.4, Northern Area Eastern Conference and Exhibition, NACE International, Ottawa, 1999.

Links:

Office of Pipline Safety, U.S. Department of Transportation:
http://ops.dot.gov/

Industry page in corrosion-club.com

Comprehensive information on GPS (by Peter H. Dana, The Geographer's Craft Project, Department of Geography, The University of Texas at Austin) at:
www.utexas.edu/depts/grg/gcraft/notes/gps/gps.html

"GPS World" publication at:
www.gpsworld.com

Natural Resources Canada - Pipeline Integrity Internet Icon (PICon) at:
http://www2.nrcan.gc.ca/mms/picon/main_e.asp