AWWA ACE56250

In 2000, a new two part spray applied material based on polyurethane was approved by the Drinking Water Inspectorate in the United Kingdom, for application to potable water mains. The main benefit of this new material is its cure time which allows return to service after 30 minutes compared to existing epoxy resins that require 16 hours. The increase in early hoop stress enables the spraying of large diameter pipes that is not currently widely available with epoxy resin while being significantly less costly than the alternative of installing a polyethylene liner. After testing the new material on small diameter mains, Yorkshire Water undertook the successful lining of an 825mm diameter 100 year old cast iron pipe. This paper covers this trial and its conclusions and how this new technology is now being used to line large diameter mains throughout Yorkshire. It also details the benefits to customers, potential cost savings and shorter construction time which in turn has resulted in reduced traffic disruption. Includes 5 references, tables, figures.