A method of making cerium citrate includes combining cerium carbonate and citric acid to produce cerium citrate and carbon dioxide. The cerium citrate is substantially free of negative ions other than citrate. The cerium citrate can be used in a corrosion inhibitor composition.

A method of making cerium citrate includes combining cerium carbonate and citric acid to produce cerium citrate and carbon dioxide. The cerium citrate is substantially free of negative ions other than citrate. The cerium citrate can be used in a corrosion inhibitor composition.

A cathodic protection (CP) interruption system includes a metallic structure and a plurality of passive CP units embedded in an electrolytic medium, a plurality of test units electrically coupled with the structure and each of the CP units, and a low-power consumption component arrangement. The arrangement includes a real-time clock (RTC) and a GPS receiver coupled with each test unit for receiving GPS time from a GPS satellite. A controller is communicatively coupled with each RTC and GPS receiver for activating the GPS receiver once the RTC reaches a predetermined time to synchronize a RTC time of each RTC with GPS time. Interruption modules are coupled in electrical and data communication with the controller. The controller selectively changes an activation state of each interruption module once the RTC time reaches a predetermined activation state change time to selectively electrically couple or decouple each CP unit from the structure.

A cathodic protection (CP) interruption system includes a metallic structure and a plurality of passive CP units embedded in an electrolytic medium, a plurality of test units electrically coupled with the structure and each of the CP units, and a low-power consumption component arrangement. The arrangement includes a real-time clock (RTC) and a GPS receiver coupled with each test unit for receiving GPS time from a GPS satellite. A controller is communicatively coupled with each RTC and GPS receiver for activating the GPS receiver once the RTC reaches a predetermined time to synchronize a RTC time of each RTC with GPS time. Interruption modules are coupled in electrical and data communication with the controller. The controller selectively changes an activation state of each interruption module once the RTC time reaches a predetermined activation state change time to selectively electrically couple or decouple each CP unit from the structure.

A tubular includes a carbon steel main body defining a first flow passage. The carbon steel main body includes a first end and a second end. The carbon steel main body includes a beveled edge at the first end of the carbon steel main body. A corrosion resistant pup defines a second flow passage in-line with the first flow passage. The corrosion resistant pup includes a substantially same inner diameter and outer diameter as the carbon steel main body. The corrosion resistant pup includes a first end and a second end. The corrosion resistant pup includes a first beveled edge at the first end. The corrosion resistant pup is connected to the carbon steel main body by a weld along the beveled edge of the carbon steel main body and the beveled edge of the corrosion resistant pup.

A carbon steel main body defines a flow passage. The carbon steel main body includes an end. The carbon steel main body includes a beveled edge at the end. A corrosion resistant cladding is deposited along an inner surface of the carbon steel main body. The corrosion resistant cladding extends from the end to a distance into the carbon steel main body.

Assemblies and methods for maintaining cathodic monitoring of underground structures may include an electrode watering assembly having a cap that includes a cap body of a rigid material defining one or more chambers adjacent to a proximal electrode end of a permanent reference electrode when installed thereon. The cap body may include a distal cap end defining a distal opening configured to be disposed around the proximal electrode end and a proximal cap end defining a proximal opening. The electrode watering assembly may include a conduit having a flexible material. The conduit may include a distal conduit end configured to be fluidly coupled to the proximal opening and a proximal conduit end configured to be positioned at a cathodic test station, such that fluid directed into the proximal conduit end is directed through the conduit and into the one or more chambers for watering at least the proximal electrode end.

A heat exchanger, includes a heat exchange pipe unit and a fin unit, the heat exchange pipe unit includes a refrigerant input pipe, a heat exchange pipe assembly and a refrigerant output pipe; the refrigerant input pipe is connected to one end of the heat exchange pipe assembly; the refrigerant output pipe is connected to the other end of the heat exchange pipe assembly; the fin unit is fixedly arranged outside of the heat exchange pipe assembly; the heat exchange pipe assembly and the fin unit are made of aluminum alloy; and the corrosion potential of the aluminum alloy which forms at least a part of the heat exchange pipe assembly is greater than the corrosion potential of the aluminum alloy which forms the remaining part of the heat exchange pipe assembly.

A monitoring system (10) for monitoring parameters of a fluid heater. The heater (30) comprises a storage vessel (32) for storing heated fluid therein. The monitoring system (10) includes a first sensor (12) and associated first electrical metering circuitry (14), a second sensor (16) and associated second electrical metering circuitry (18), and a control switch (22). The control switch (22) is operable so as to be able to adopt a first mode of operation in which the first electrical metering circuitry (14) is activated, and, a second mode of operation in which the second electrical metering circuitry is activated. The monitoring system (10) also includes a controller (24) for causing periodic operation of the control switch so that it switches between the first and second modes of operation.

The invention provides an in situ method for protecting material exposed to molten salt, the method having the steps of supplying metal in a first nonreactive state to the molten salt to create a mixture; measuring a redox state of the mixture; and transforming the metal to a second reactive state when the redox state indicates corrosion of the material is about to occur. Also provided is a system for preventing corrosion of structural alloys in molten salt environments, the system having a vessel defining a void containing the molten salt; a voltammetry sensor inserted into the molten salt; a first cathode inserted into the molten salt; and a first anode inserted into the molten salt, whereby the cathode and anode are in electrical communication with an electrical power source.