Project Appreciation and Objectives
New polyethylene (PE) pipes do not offer the leak-free solution previously envisaged, mainly due to the conditions found on site and the level of skill required to carry out the jointing work. With industry estimates of one in five site-made joints leaking or failing, each new PE pipe laid has the potential to further contribute to water losses. Leaks on PE pipes are also typically harder to find. The reasons for most failures in PE pipes are understood: the correct choice of joint type together with the appropriate level of training and supervision can reduce the risk of premature failure and the cost of remedial work during the lifetime of the pipeline.
Understanding leakage from a growing cohort of PE pipes and a focus on reducing unwanted customer contacts to minimise SIM scores are leading to closer examination of joint selection and site practice. It is therefore timely to quantify the costs and benefits of different PE jointing methods to inform future company policy.
This project will deliver quantified relationships related to PE installation methods which will help participants to determine the most cost-effective route when designing and procuring new PE schemes. The resultant model framework will allow practitioners to take account of the benefits and avoided costs from alternative policies on site supervision, training, reliability and suitability of jointing methods.
Business Benefits to Clients
- More informed decision making on future spend on product, supervision and installation contracts.
- Understanding the influence that procurement choices and working practices have on leakage and customer service.
Project Output and Implementation
- Develop a robust method of calculating the whole life costs of PE pipe joints;
- Quantify the costs associated with purchasing, installation and ensuring quality ;
- Quantify the potential for avoiding cost (i.e. benefits) of later repair interventions by understanding factors which impact on the leak flow rate from PE joints;
- Provide a cost-benefit tool to allow companies to assess the most cost-effective jointing technique for a range of circumstances e.g. by location, diameter, local environmental conditions.
- Prepare worked examples to demonstrate how the cost-benefit assessment tool may be implemented.
Spreadsheet tool constructed in MS Excel 2010 to assess the whole life costs and benefits of different PE jointing methods and assist in developing future product purchasing and installation contract requirements. The tool will include user-editable parameters to allow asset planners to incorporate their own schedule of rates, product selection and contractual arrangements. It will be supported by a report detailing model data sources, methods of quantification of costs and benefits, and worked examples.
Related WRc Work
- Cost benefit analyses and economic level of leakage assessments for water companies.
- Mains interventions - Improving benefits valuation, CP338, 2010.
- True consequences of asset failure on service in distribution, CP463, ongoing.