Pipe Cleaning Using an Abrasive Stone and Vacuum

Abstract

Municipalities and water utilities across the globe provide potable water to domestic, business and institutional consumer through thousands of kilometres of distribution and transmission pipelines. A large percentage (often over 50%) of water distribution pipes have been in service for over 50 years with little to no maintenance, rehabilitation and/or renovation. Pipe aging and deterioration have resulted in a significant increase in poor quality water at the tap and increased annual water utilities costs to fix an exponentially increasing number of leaks and breaks. Digging up old pipelines to install new pipelines, typically under streets and highways, is extremely costly and disruptive to residents and businesses and can result in large greenhouse gas emissions. An alternative to open-cut replacement is to use the old, insitu pipe as a form to build a new “pipe within the pipe” using cured-in-place pipe (CIPP) or spray in-place pipe (SIPP) methods. This paper discusses the importance of pipe cleaning and preparation prior to the installation of CIPP or SIPP liners. A new waterless pipe cleaning method (Tomahawk System) that uses abrasive stones under a low pressure condition is then described. This is followed by a description of a field pilot program to determine the benefits of three pipe cleaning methods: Tomahawk, rack-feed boring and hydro-jetting. The Tomahawk System was found to clean the pipe fastest using no water or swabbing and was also able to prepare the pipe surface to meet NACE WAB-2 requirments (near white metal finish). The Tomahawk was also found to provide superior pipe cleaning and preparation for liner adhesion and interlock. Liner adhesion and interlock are deemed critical for SIPP and CIPP liners’ long-term preformance.