Detection for Flexible Water Pipeline Inspection and Disease Analysis

Underground pipeline serves as the "lifeline of the city" and is closely related to people's everyday life. Both rigid and flexible material are used in the production of these pipes; the former includes concrete and clay and the latter includes unplasticised polyvinyl chloride (UPVC) and polyethylene. Due to the serious results the pipeline malfunction may bring about, it is of great importance for non-excavated pipeline inspection to be conducted. Current inspection methods include: closed-circuit television (CCTV) inspection, sonic distance measurement, and quick view method. An overview of the features of both rigid and flexible pipes as well as the current methods for underground pipeline condition assessments is presented in this paper. Besides, an application of closed-circuit television (CCTV) inspection method on water pipelines is reported. The water pipes, called double wall corrugated pipes, are made of high-density polyethylene (HDPE) material. Problems detected during the inspection are listed and factors contributing to the pipe deterioration are categorized into three aspects, namely, material factor, construction features and local external factors. General suggestions are made regarding possible directions for further research at the end of this paper.