Abstract
A report is given of the practical considerations involved in the cathodic protection of the coated steel gas main distribution system in New Orleans. Topics discussed include topography and soils in New Orleans, types of gas mains used in system, use of coatings, use of galvanic anodes, experience with rectifiers and ground beds, use of insulated joints, importance of educational programs, and cost of cathodic protection. Data are given for a portion of one periodic rectifier survey and yearly tests on three galvanic anodes.
Results secured were good. It was found that successful operation of cathodic protection in New Orleans could be materially aided by observing the following procedure: (1) Secure reasonably good coating of the mains to be protected, (2) Maintain the systems to be protected electrically continuous, and free from electrical contact with other metallic subsurface structures, (3) Maintain the electrical potential of the systems to be protected at least —0.85 volt to a copper sulfate reference electrode placed in the earth, (4) Maintain continuous operation of the device furnishing the current for cathodic protection, (5) In general use many small (rather than a few very large) units for furnishing the cathodic protection currents. This minimizes problems of cathodic coordination. 5.2.3
