Proving Grounds for Evaluation and Comparison of Metallic and Reinforced Concrete Buried Water Transmission Lines
How well do different types of water pipe and protective methods perform in corrosive soil conditions?
Need and Benefit
BOR needs to begin an extensive long term program to evaluate methods of protection on various types of pipes, coatings and encasements that are used on pipeline systems.
Pipelines are used for water conveyance; protecting pipe from corrosion reduces the maintenance, repairs, and replacement costs. Therefore, it is important to protect the pipelines as long as possible. Protective coatings, tape wraps, and polyethylene encasements are used in conjunction with cathodic protection to minimize corrosion. There are numerous products to choose from, including some new technology. Without a performance testing program it is becoming difficult to know that a particular product is the best means of protection for a specific application.
The majority of Reclamation pipelines are buried. As a result, buried environments are significantly different from above ground conditions. Soil conductivity and ions are an important part in the deterioration of the pipeline. Aggressive soils have a high concentration of ions, are very conductive, and generally go through a wetting and drying cycle. Reclamation used to conduct some burial exposure studies of pipeline at Marston Lake, (just south of Denver), which had the proper soil conditions for an aggressive environment. It would be beneficial to conduct burial studies to evaluate different protective coatings and encasements.
Different types of pipeline could also be investigated for new installation of pipeline to meet the needs of Reclamation customers. The program would determine what type of pipeline is the most cost effective and longest lasting for planning of new construction or installations. The water demand is always increasing, especially in the west, where new installation is inevitable. Testing different pipeline types will provide the knowledge to specify the most cost effective system.
A pipeline is only as good as its weakest link. With this in mind, many failures are not along the solid pipe section, but at the joints. Part of the study will consist of examining different types of joints and materials to protect those joints.
BOR would benefit from reduction in maintenance costs and fewer repairs. Another benefit would be to develop a new method of corrosion detection and monitoring of the polyethylene encasement type protection, currently there is not one.