Monitoring Buried Pipe with Permanently Installed Guided Wave System

Guided Wave ultrasonic inspection offers definite advantages for assessing the condition of buried piping or piping that is difficult to access for inspection. In the case of buried piping, excavation costs can easily exceed the cost of the inspection. Guided Wave monitoring systems (PIMS) are now available for situations where periodic monitoring is appropriate as opposed to repair or replacement. These systems eliminate re-excavation costs for re-inspection and offer enhanced sensitivity in subsequent monitoring inspections. This application is especially applicable for hydrant fuel systems. PIMS are now now being used extensively by nuclear power plants to monitor the condition of buried service water systems and and the pipeline industry to monitor cased pipe sections.

The typical installation follows a guided wave inspection where indications have been determined to be acceptable for continued operation but the operator chooses to monitor the condition until repair or replacement is necessary. The technical advantage is that the initial guided wave inspection provides a baseline to which future inspections can be compared. Changes as small as 1% in the pipe condition can be detected after the initial baseline inspection.

This presentation describes the conditions for the use of a monitoring system, their technical advantages, installation procedures and longevity.