SoundPrint® AFO - PCCP Wire Break Monitoring

SoundPrint® AFO (Acoustic Fiber Optic) is a fiber optic monitoring system used to detect and locate wire failures in prestressed concrete cylinder pipe (PCCP).

3D Plot of Pipe Distress

Technician Installing Fiber



  • Potable Water
  • Raw Water
  • Wastewater

Pipe Types

Pipe Diameter

24" (600mm) and larger

Related Media

When developing a management program for a PCCP pipeline, there are two very important variables to consider:

  • The Baseline Condition of the Pipeline - Condition Assessment
  • The Rate of Deterioration - Pipeline Monitoring (SoundPrint AFO)

With this information a reasonable estimate on the remaining useful life can be ascertained. Electromagnetic inspections provide the baseline condition of a pipeline where SoundPrint AFO acoustic monitoring determines which pipes within the line are actively experiencing wire failures which ultimately provides the rate of deterioration.

What is SoundPrint AFO?

SoundPrint AFO technology continuously monitors the acoustic activity in a pipeline to identify the acoustic events associated with the failure of prestressing wires. SoundPrint AFO continuously tracks the condition of each pipe in the line and reports the time and location of breaking prestressing wires. Thus acoustic monitoring can identify actively deteriorating pipe sections and determine the rate of deterioration.

How Long Should a Pipeline be Monitored?

In general, SoundPrint AFO is used to accomplish one of two objectives: short term pipeline assessment or long term pipeline management. Long term management of PCCP mains involves the long term installation of the acoustic monitoring equipment thereby converting an existing main into a SmartPipe. With a SmartPipe the condition of the main is continuously reported so operators can identify problems as they develop to minimize the risk of failure.

For condition assessment programs relying on acoustic monitoring, there is no simple answer on how long to monitor a pipe. The longer the monitoring program, the better the assessment. It is known that pipes can go through periods of reduced wire break activity, when there is no wire break activity followed by periods of increased wire break activity on individual pipe sections. The monitoring period should be long enough to extend past the inactive periods to permit the identification of deteriorating pipe sections, if any. Pure Technologies recommends a minimum three month monitoring program.

SoundPrint AFO Configurations

SoundPrint AFO is provided through one or more combinations of several different sensor configurations. These multiple configurations permit the most flexibility when implementing a system, so a cost effective and reliable monitoring program can be implemented on almost any PCCP main. The SoundPrint system uses the following sensor configurations:

  • Hydrophone Arrays - cable installed inside up to 5000 feet of pipe with numerous hydrophones embedded on the cable
  • Surface Mounted Sensors - piezoelectric sensors adhered to the surface of the pipe or on appurtenances along the pipe
  • Hydrophone Stations - individual hydrophones inserted into the water flow through existing appurtenances
  • Fiber Optic Sensors - Glass fiber installed inside the pipe where the entire fiber is acoustically sensitive

SoundPrint AFO Advantages

  • Detects actively deteriorating PCCP sections
  • Pipelines remain in service while monitoring is performed
  • Proven history and the most reliable acoustic monitoring technology for PCCP
  • Numerous sensor configurations permit flexible monitoring solutions
  • Close sensor spacing ensures wire breaks are reliably detected and accuratley located

All wire breaks are located and reported in near real-time through a web based reporting system

SoundPrint AFO is Applicable for

  • Prestressed Concrete Cyclinder Pipe (PCCP)
  • Potable water, raw water, and wastewater
  • Pipelines 24-inches and larger

Learn More

Washington Suburban Sanitary Commission Avoids Critical Failure Through the use of Fiber Optic Monitoring

Washington Suburban Sanitary Commission Avoids Critical Failure Through the use of Fiber Optic Monitoring

To prevent critical water main failures, the Washington Suburban Sanitary Commission (WSSC) has installed acoustic fiber optic cable in many of its Prestressed Concrete Cylinder Pipe (PCCP) transmission mains. This technology has prevented a number of major pipeline failures, most recently in Prince George’s County on a 54-inch transmission main.

CONAGUA Case Study

CONAGUA Prevents Failure on the Cutzamala Pipeline

After prestressed wire break activity on the Cutzamala Pipeline in March 2013, CONAGUA intervened on two pipe sections that were badly distressed, taking quick and decisive action to prevent a failure. The transmission main had previously been inspected using PipeDiver® technology in July 2012.

Baltimore City Case Study

Case Study: Baltimore City

In summer 2012, Baltimore City Public Works (BPW) intervened on a critical 54-inch PCCP pipe that was showing signs of distress. The pipe section was replaced and service resumed after avoiding a major pipe failure.