Baltimore County, Maryland has implemented a state-of-the-art assessment and
management program for one of their PCCP water transmission mains. The
transmission main is 48-inch supply feeder from a major pumping station to a large
finished water reservoir. A major focus of their assessment program has been to utilize
non-destructive techniques to assess the main and identify actively corroding PCCP.
The program consisted of two phases: electromagnetic testing simultaneously with
visual inspections for Phase 1; and, acoustic monitoring for Phase 2. The Phase 2
program was subsequently revised based upon the results from the initial Phase 1
inspection and the simultaneous availability of evolving technologies.
Phase 1 results showed that approximately 16 percent of the pipe sections comprising
the 1.5 mile pipeline inspected exhibited wire breaks. Four pipe sections were
identified as requiring immediate replacement before the main could be returned to
service. Subsequent to pipe replacement, the four pipe sections were dissected as a part
of forensic analysis. The actual number of wires broken were compared with those
previously predicted using the electromagnetic inspection techniques.
Following the Phase 1 inspection, the County's Phase 2 assessment program was
modified to incorporate new technology which uses "fiber optics" in lieu of the planned
"acoustic" technology. The fiber optic technology is being used to monitor on-going
wire breakage over a 90-day period. In addition, and for trial purposes, both
technologies are also being compared side by side for a short section of the pipe being
monitored.
The paper uses the case study of the Baltimore County main to discuss corrosion
mechanisms of PCCP, to review the latest technologies and methodologies available to
assess the PCCP main, and to critique the results stemming from their employment in
the pipeline assessment and management program. Includes reference, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 350 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 9 |
| Published : | 06/01/2006 |
