Pure Technologies Verifies Afo Wire Break Activity Wssc
As part of a comprehensive pipeline management program, Washington Suburban Sanitary Commission (WSSC) and Pure Technologies have been monitoring sections of Prestressed Concrete Cylinder Pipe (PCCP) using Pure’s Acoustic Fiber Optic monitoring since 2007.
In October 2012, WSSC took the opportunity to proactively verify a 0.5 mile section of the River Road transmission main that had experienced elevated wire break activity. The individual pipes to be rehabilitated were selected from a comprehensive list of all monitored pipelines that contains all pipe sections that have an elevated risk of failure according to Finite Element Analysis and a combination of data sets, primarily collected from electromagnetic (EM) inspections and AFO monitoring.
This is part of a new drive from WSSC to initiate repairs on pipelines experiencing a high number of wire breaks before the situation becomes critical and prior to the normal 5 to 6-year inspection cycle.
Using an EM verification tool and internal visual and sounding, Pure verified all the wire breaks recorded with AFO and determined that all of the pipes were significantly more distressed than they were two years ago after the initial EM inspection.
In addition to the wire breaks, a hollow section was found on one of the pipes that signals a broad loss of prestressed wires. This hollow section was not found during the initial EM inspection and shows that the pipe section was beyond its allowable amount of wire break damage.
The verification of the four damaged pipe sections on River Road shows WSSC’s commitment to preventing pipeline failures through ongoing proactive pipeline management.