Detecting breaks in prestressing pipe wire

Prestressed concrete pressure pipe (CPP) is in widespread use throughout Ca nada and the United States, with a total of some 19,000 mi (30,000 km) of p ipe in use in North America's major water utilities. Many of these lines ar e more than 50 years old, and half are expected to need repair or replaceme nt over the next 20 years. To selectively maintain these lines and avoid co sts from catastrophic pipe failures, utilities needed an inspection techniq ue that was highly sensitive, reliable, effective, and economical, An innov ative electromagnetic technique, based on the remote field eddy current (RF EC) inspection technique, has been developed that allows nonintrusive inspe ction of prestressed CPP, Full-scale testing conducted on embedded cylinder pipes and bar-wrapped pipelines demonstrated the new RFEC technique's sens itivity to both single and multiple breaks in prestressing wire.