Water pipeline condition assessment using transient response analysis

Abstract

Constriction and blockage due to ageing and deterioration is a common problem in water pipeline systems throughout the world. Preliminary pipework investigations can be undertaken using steady state pressure and flow measurement tests. A further investigatory step that may be taken is the use of CCTV cameras. However, there are a number of difficulties that ultimately reduce the effectiveness of CCTV camera inspection systems including lack of access to pipelines (and limited range), internal obstructions prohibiting inspection and the difficulties associated with assessing some aspects of condition visually (e.g. pipe wall thickness). Controlled transient events have been applied to two water distribution pipelines and a trunk transmission pipeline, and the pressure response measured at high speed, to obtain information in addition to that available from steady state pressure and flow measurements. Subsequent analysis of the transient response of the pipelines demonstrated that both discrete and extended blockages could be successfully diagnosed without the need for further CCTV camera investigation. Furthermore, direct measurement of the wave speed in the pipelines enabled an assessment of the condition of the pipe walls.