p-CAT™ case study
p-CAT™ condition assessment was applied to a 16 inch MSCL water main for SunWater during June 2016. The aim of the project was to examine the pipeline integrity and provide the findings to SunWater in order to assist in the prioritisation of their water main maintenance program.
A comprehensive desktop study and site inspection were undertaken prior to p-CAT™ testing in order to develop a tailored test plan for the pipeline. The established test plan enabled high quality results to be collected within the allocated time frame with minimal disturbance to the system operation.
During testing, p-CAT™ equipment, which includes a pressure transducer, a data acquisition box and a transient generator, were attached to existing pipeline fittings – primarily air valves. A small, carefully controlled pressure transient was introduced into the pipeline at a number of locations along the assessed section, and the resultant data captured and collated.
Testing was conducted at nine locations within two days allocated for field works. The original scope of work was to assess 5 km of pipeline. However, Detection Services were able to collect sufficient data for the analysis of 14 km of pipeline within the two days.
The collected data was subsequently analysed using an advanced and patented algorithmic method based on the speed of the transient signal. p-CAT™ analysis has determined the remaining wall thicknesses for 37 sub-sections of different deterioration conditions over this 14 km section, and has also identified and located a number of anomalies including a potential service connection not known to SunWater and a deteriorated section.
Another significant finding is the presence of high air content, which is potentially the main cause of deterioration of this section. The locations of known pipeline features, including air valves, scour valves and an opened off-take were also identified during the analysis.
During p-CAT™ testing, Detection Services also identified potential issues related to the operation of the pump station. The field observations regarding the pump cycle times and transients generated during pump start and stop sequences, together with potential consequences and recommendations were also provided to SunWater.
p-CAT™ results have provided a comprehensive understanding on the condition of the pipeline as a results of the integrated and collaborative work environment supported by SunWater during the planning and testing phases.