Part 1
Like many things, the way an idea is implemented usually has a major impact upon its success. In the world of corrosion control using cathodic protection (CP), this is translated to proper installation of the system. Although there are many configurations, often the system consists of multiple galvanic anodes placed in what is referred to as a “groundbed”.
While these systems may seem simplistic in nature and appearance, most come with their share of complications such as cased road crossings, foreign pipeline crossings, and areas where the installation of electrical isolation is required by the design. These complications need special treatment with regard to proper installation of components required by local standards and the design. Those complications include critical parts of the installation that can ultimately determine whether the CP system works properly to prevent corrosion and whether the system continues to work for the intended design life.
Generally, the installation of a CP system designed for residential water line use is required to be tested. The majority of the tests involve verifying that the CP system components are installed correctly and are operating properly. Each type of specialized test station has its own test to verify proper installation as it relates to the pipe, and the CP in many cases. Sometimes the results of the testing verifies whether everything is installed properly, or if it isn’t.
When testing recognizes that parts of the CP system are not operating properly the first consideration for the cause is installation. Many of the seemingly mundane aspects of the installation may not seem that important to the CP operation, but items such as an improper crimp, damaged wire, weak weld, or poor coating repair can be critical. Any of these aspects of the installation may require repair in order for the system to operate properly, and retesting. In many cases, there are multiple installation errors that dramatically impact the performance of the CP.
Typically, the critical installation errors that negatively impact CP installation are discovered at the end of the project, after the backfill, landscape, and cleanup are performed. It’s no secret that the majority of the cost for underground utility installations is related to the excavation, the dirt work. Especially, when it is done more than once.
