Transmission Main Inspection and Assessment

Transmission Main Inspection and Assessment

Transmission Main Inspection and Assessment

Since 2011, we have been providing inspection and condition assessment to Phoenix’s 42-inch and larger prestressed concrete cylinder pipe (PCCP) water mains. Through this program, we’ve inspected 22 distinct projects or scenarios, totaling over 57 miles of transmission pipeline.

For each of the 22 scenarios, we led all communication with the City and their job order contractor (JOC). This included the development of shutdown and startup plans, detailed dewatering and refilling operations, as well as in-line and side outlet valve repair and replacement. We managed the City’s JOC on a task-by-task basis throughout all planning and assessment activities.

An Inspection and Monitoring Plan was developed for each pipeline describing technologies and techniques to be applied. Inspection and monitoring protocols included internal electromagnetic inspections, internal visual and sounding inspections, external corrosivity surveys, external visual inspections, external continuity testing and pressure transient monitoring. We trained City staff with hands-on experience in shutdown/startup planning, visual/sounding inspection, pipe dissection and transient pressure monitoring.

Based on assessment results, we recommended emergency repairs (spot carbon fibre reinforced polymer or selective replacements), minor maintenance (repairs of joint grout, leaking or broken valves), long-term rehabilitation and future inspection activities.

Transmission Main Inspection and Assessment
Client
City of Phoenix
Location

Phoenix, AZ
United States

Size
57 miles