# SOUTHWEST RESEARCH INSTITUTE^®^ {#southwest-research-institute .nTitle}

# Quarterly Status and Progress Report for Period Ending October 31, 2007 {#quarterly-status-and-progress-report-for-period-ending-october-31-2007 .nTitle}

# Other Transaction Agreement DTRS56-02-T-0001 SwRI^®^ Project 14.06162 {#other-transaction-agreement-dtrs56-02-t-0001-swri-project-14.06162 .nTitle}

# APPLICATION OF REMOTE-FIELD EDDY CURRENT (RFEC) TESTING TO INSPECTION OF UNPIGGABLE PIPELINES {#application-of-remote-field-eddy-current-rfec-testing-to-inspection-of-unpiggable-pipelines .nTitle}

## Phase 3---Development of RFEC System and Integration with Explorer II Robot

Many pipelines contain internal restrictions that do not allow the
passage of inspection pigs that use conventional inspection technology.
In the current phase of this project (Phase 3), a remote-field eddy
current (RFEC) system is being developed to accommodate internal
restrictions**.** This system will be fabricated and integrated with the
Explorer II robot under development by Carnegie Mellon University (CMU).
The integrated system will be tested on a live operating pipeline.

The Explorer II robot consists of a series of 11 modules that are linked
together to form a self-propelled device that can travel untethered
through a pipe. The robot is designed for pipe that ranges in diameter
from 6 to 8 inches. In order to accommodate sharp bends in the pipe,
however, the robot must have the capability to collapse to 4 inches in
diameter**.** RFEC inspection capability is being added to Explorer II
by developing two modules, one containing an excitation coil and the
other an array of 48 sensors on spring-loaded, retractable arms. The
arms expand to the required pipe diameter for inspection and retract to
4 inches to negotiate bends or obstacles in the pipe.

During the current reporting period, the RFEC system, as integrated with
Explorer II, was subjected to endurance testing on the outdoor
above-ground pipe loop at CMU, as well as to validation testing on
schedule 40 and 0.250-inch wall, 8-inch diameter pipes with simulated
corrosion defects.

A field test of the system was held during the week of September 10,
2007 in Brookville, PA. The following observations were made for the
RFEC portion of the system.

-   The RFEC data appears to be of good quality, although analysis has
    not been completed.

-   The RFEC sensor shoes successfully traversed welds and service taps
    while fully deployed.

-   No damage to the RFEC sensor shoes resulted from the sharp edges of
    the entrance hole during launch/unlaunch.

-   The RFEC sensors were successfully deployed and retracted about 10
    times while in the pipe.

-   RFEC data were successfully transmitted over the Explorer II
    robot\'s wireless link and were also stored on internal flash
    memory.

-   No significant wear occurred to the RFEC sensor shoes or protective
    tape.

-   RFEC data were taken with active cathodic protection (CP) turned on
    and off, and no apparent effect of CP was observed.

## Point of Contact

Gary L. Burkhardt, Staff Scientist

Applied Physics Division

Southwest Research Institute

6220 Culebra Road

San Antonio, Texas 78238

\(210\) 522-2075

\(210\) 684-4822 fax

<gburkhardt@SwRI.org>