Patent ID: 8153057

Claim:
A method of controlling a real-time oxidation-reduction potential (“ORP”) in a hot water system to inhibit corrosion in the hot water system, the method comprising: (a) defining one or more operational protective zones (“zone” or “zones”) in the hot water system; (b) selecting at least two of the defined zones, wherein at least two of the selected zones includes at least one ORP probe operable to measure the real-time ORP and communicate with a controller; (c) either intermittently or continuously measuring the real-time ORP at one or more of the selected zones while the hot water system is at operating temperature and pressure; (d) transmitting the measured real-time ORP to the controller; (e) assessing whether the measured real-time ORP or a calculated ORP based upon the measured real-time ORP conforms to an ORP setting, wherein the ORP setting is either a same ORP setting for each of the selected zones or a different ORP setting for at least two of the selected zones; (f) feeding an effective amount of one or more active chemical species into the hot water system, if the measured real-time ORP or the calculated ORP does not conform to the ORP setting; and (g) ramping from one of the selected zones to another one of the selected zones after a triggering event.