METHOD AND APPARATUS FOR PROTECTING UNDERGROUND METAL MULTIPLE-PIPE MAINS FROM ELECTROCHEMICAL CORROSION Russian patent published in 2003 - IPC

FIELD: protecting facilities for underground pipelines. SUBSTANCE: method involves using three one-phase direct voltage sources, input supply busbars, plus and minus loading output busbars, plus and minus busbars for measuring circuits connected with one another in predetermined manner. Apparatus is used for protecting multiple-pipe mains, water pipelines, communication cable pipelines and other extended underground metal constructions from electrochemical corrosion. Construction of apparatus allows shielding of one pipeline by another pipeline to be eliminated, one multiple-channel cathode protection station to be connected to three-phase supply mains and, accordingly, only one station to be used instead of three such stations, and weight of ferrite steel and copper wires used in apparatus to be reduced as compared to those used for three stations. Besides, protective pulsating current rate on pipelines is reduced. EFFECT: increased efficiency and simplified method by reduced labor intensity due to employment of one cathode protection station instead of three such stations. 6 cl, 3 dwg