| Contents Notes |
The social importance and economic cost of water and sewage pipelines make it essential to maintain them in good working order. Corrosion is one of the most common factors in their alteration and possible, untimely destruction, but it can be prevented or controlled, usually at a relatively low cost. Based on an analysis of existing literature and a number of case studies, this document suggests a series of guidelines for effective corrosion control. Water treatment can play a key role in preventing or controlling internal pipe corrosion; the use of appropriate linings can protect metal components. Coatings or protective outer thin plastic sleeves can effectively guard pipelines against corrosion from external factors. Cathodic protection is also effective, but should be used only where required. New techniques are being developed for rehabilitating old pipelines to extend their functional life, thereby avoiding costly replacement. These processes require, however, a high level of expertise as well as specialized equipment; urban areas in developing countries with relatively newer and smaller pipeline networks and labor costs may therefore find rehabilitation to be a less cost-effective and attractive option. |
