An Evaluation Of Failure Modes For Cast Iron And Ductile Iron Water Pipes

Abstract

The need to evaluate the performance of cast iron and ductile iron water pipes is of great importance since they are the most common pipe materials for water mains. The concern in the water industry is about the cost involved in repairs and replacement of water pipes due to failure. The rate of pipe failures increases as the design life ends and become a financial burden on the water industry. This thesis evaluates the failure modes for the two most used pipe materials for water mains in the United States which are cast iron and ductile iron pipes. A study based on 15 survey responding water utilities on different failure parameters such as age of the pipe, diameter, manufacturing process, type of joints and type of failure will help in identifying future research areas. This thesis consists of a detailed literature review and a limited survey conducted to gather failure data of from several water utilities in the United States. The thesis concludes that stress failure is the most commonly occurring mode of failure followed by corrosion failure and joint failure for cast iron and ductile iron water pipes and provides a limited prediction of water main problems only for the inventory water utilities which responded to the survey.