Cathodic protection setpoint

So they build whole pipelines, and in the areas where they have AC electricity, they put in a rectifier, create DC electricity, put electrodes in the ground, and they actually make the whole pipeline 0.85 volts to a reference electrode. And it will keep the thing from corroding for a hundred years, a thousand years. When they're somewhere where they don't have electricity — I was out in west Texas where they're putting in some transmission towers — they use zincs. At the very back of this handout, they talk about marine corrosion and how they use zinc as the sacrificial anode, and the sacrificial anode corrodes rather than the ship's hull. Or they put on an electrical system — they have an insoluble anode and insulation and everything else, but they essentially are impressing electric current. That's what we do for nuclear subs.