Denver Water
PPIC field technician inspectiing a pipeline with PipeRider
Pipe Diameter: 60"
Pipe Type: PCCP
Distance Inspected: 1.08 miles
Service: PipeRider™- Remote Field Transformer Coupling (RFTC)
Denver Water serves a population in excess of 1.1 million people in the Metro Denver area and operates over 2,600 miles of water transmission mains. Denver Water was one of the first utilities to implement a Condition Based Asset Managment program for its prestressed concrete cylinder pipe (PCCP) pipelines. To date, Denver Water Utility has inspected 23 miles of PCP using the patented Remote Field Transformer Coupling (RFTC) technology from the Pressure Pipe Inspection Company (PPIC) to establish the baseline condition of some of its more critical PCP assets.
Due to the need of this water utility to move additional water from one treatment plant to another one, the Chief of Engineering was interested in determining if it was safe to raise the hydraulic gradient in Conduit No. 30 by 20 to 30 psi. "Our choices are raising the pressure in this line, or building a new one," said the Chief of Engineering. "For budgetary control purposes, we’d obviously prefer to raise the pressure in the line. However, before doing so, we needed to determine its structural condition. RFTC provides data on the structural integrity of PCP. Only with accurate data, can we asses the risk that this pressure increase will have on individual pipes."
Conduit No. 30 is a 60" diameter PCP pipeline that was manufactured by International Pipe & Ceramics Corporation in 1963 and does not contain shorting straps.
On August 17, 2005, PPIC conducted a non-destructive evaluation of Conduit No. 30 using the RFTC technology. The RFTC inspection was performed between STA 5+32 and STA 60+61, and between STA 63+02 and STA 64+82, spanning an overall distance of 1.08 miles and a total of 366 pipes. Analysis of the data obtained during this inspection determined that only seven pipes (2%) in this portion of Conduit No. 30 contained broken prestressing wires.
The Chief of Engineering stated that the inspection provided the baseline condition information that they needed to move their stress analysis program forward.