Patent ID: 7435326

Claim:
A method for controllably inhibiting the galvanic corrosion resulting from the fluid connection of two electrolyte-conveying, dissimilar, metal pipes electrically connected to a ground, the method comprising: (a) applying a protection current through the electrolyte between a pair of protection electrodes that are axially spaced from each other, interposed between the dissimilar pipes and in electrical contact with the electrolyte; (b) sensing the electrical current to ground through the electrolyte and a control electrode in electrical contact with the electrolyte and located between the protection electrodes and one of the metal pipes; and (c) adjusting the protection current to reduce the magnitude of the sensed current; wherein the method further comprises forming the control electrode of substantially the same metal as one of the pipes and positioning the control electrode between the pipe having substantially the same metal composition as the control electrode and the protection electrodes.