Other

Corrpro Companies, Inc.

Harco Corporation

Harsco Technologies Corporation

James B Bushman

Clark P Weldon

David H Kroon

William P Carlson

Stephen L Wolfson

James R Dimond

Michael K Baach

Richard E Say

Charles G Waits

Karl W Nicholas

Joseph W Rog

Wayne J Swiat

Brian C Donovan

John Hennessy

Gary Goldsmith

A method for manufacturing improved cast anodes for corrosion protection in storage tanks calls for integrating a plurality of spaced steel core rods into a sacrificial galvanic anode material sheet. The sheet is divided into segments such that a width of each segment is four to eight times the thickness of the galvanic sheet.

Combination galvanic anode and wear plate for storage tanks

A storage tank for fluids comprises a novel striker plate. The striker plate is comprised of a sacrificial galvanic anode and a steel core, and it is situated opposite an access opening used for measuring depth of fluid in the tank. The striker plate can also function adjacent other corrosive areas in a tank, such as along a seam in a tank wall, to reduce corrosion.

Reference electrode improvement

An integrated cell and the test station is disclosed in a unitary package which includes internally encapsulated wiring connections at both the cell and test station. The cell and test station are tethered together by a flexible bungee tube which can be coiled and which can elongate or contract. The flexible tube provides a variable length and wide lateral flexibility. The tube also provides a convenient means to encapsulate the connections at both the cell and test station. The cell has a unique core formed by a double junction ceramic capsule. A pure copper coil element is positioned in the capsule in a super saturated solution of copper sulphate, for example. The capsule is sealed and the coil or element is electrically connected to a lead extending through the tube, and the end of the tube is encapsulated sealing the connection. The capsule is joined to one end of the bungee tube and the entire end is embedded in a stabilized hygroscopic gel which contains additional salt crystals. The entire cell end of the tube is contained in a microporous filter bag, which is in turn secured to the lower end of the tube. The test station comprises a section of rigid plastic tube with a slightly domed cap. Brass rivets are recessed in the top of the dome and connected to appropriate wiring inside the dome. The interior of the test station is then encapsulated fully sealing the wiring connections, and connecting the rigid tube to the bungee tube.

Reference cell

Non self-passivating cathodic protection anode materials such as graphite and high silicon iron are treated to improve corrosion resistance. Anodically stable oxide coatings such as cobalt oxide (cobalt spinnel) or precious metal oxides are received on the underlying anode substrate. The rate of consumption of the anode material during the operation of the cathodic protection system is dramatically reduced.

Catalytically coated anodes

Impressed current anodes such as cathodic protection anodes comprise iron based alloys including less than 70% iron and less than 0.1% carbon. Additional components may include molybdenum, chromium, nickel and others. The iron based alloy may itself comprises the anode or it may provide a substrate to which an electrolytic coating is applied.

Corrosion-resistant ferrous alloys for use as impressed current anodes

An electrode is disclosed which is particularly useful as a reference electrode in cathodic protection systems. In any reference electrode or half cell, its continued stability is predominantly dependent on the metal ion concentration around it. In time such ions tend to leach away reducing the stability, effectiveness and life of the electrode. With the present invention such ions in the electrolyte may be replenished by the addition of a concentrated solution of metal salt to a ceramic canister which may include a glaze coating which may have one or more diffusion ports permitting the metal salt solution to leach at a controlled slow rate to the area surrounding the electrode ensuring continued stability and longer effective life for the electrode. The one or more diffusion ports also provide a low resistance current path to or from the lead within to the canister and the surrounding electrolyte.

Electrode

A cathodic protection monitoring system which provides IR drop free cathodic protection potential measurements which are indicative of the effectiveness of the cathodic protection system. The system measures the polarized potential between a reference electrode and a coupon subsequent to decoupling the coupon from the protected structure. The present invention controls the time or times at which the potential is measured in order to ensure that the potential is measured only after the polarized potential has achieved a relatively steady state value. More particularly, the cathodic protection monitoring system controllably measures the polarized potential after the potential has stabilized to the extent that there are no inductive or capacitive voltage spikes present, and before the coupon potential decays significantly due to depolarization. The system also can eliminate or reduce to an acceptable level the impact of telluric and other stray DC currents in the earth or structure metal path on the potential values measured.

Method and system for measuring the polarized potential of a

The invention relates to a cathodic protection system for an above-ground storage tank having a metal bottom, both new and retrofitted bottoms. A leak containing dielectric safety membrane is spaced a short distance below and extends beneath the tank bottom generally parallel thereto forming a narrow envelope. Compacted electrolytic conductor is positioned between the membrane and the tank bottom supporting the tank bottom embedding a horizontally disposed cathodic protection anode, the anode being in the form of a matrix or grid of interconnected titanium bars and ribbons. A reticulate dielectric insulator may be embedded in the electrolytic conductor and positioned directly above the anode and such insulator is operable to keep any portion of the anode from contacting the tank bottom and to maintain a generally uniform spacing between the anode and tank bottom. The ribbons extend transversely of the bars and are spot welded on uniform centers to bars on diameters or major chords of a circular tank bottom. A low profile connection is provided between the bars and power feeds to a rectifier, and for large tank bottoms a multiplicity of such connections strategically spaced are provided. Similarly, a plurality of reference cells both in location and kind may be provided so there are redundant power feeds and reference cells. The anode is constructed by uncoiling, arranging and connecting the bars and ribbons on a compacted layer of electrolytic conductor on the liner. After the conductors are attached and routed to the external rectifier, the insulator may be placed above the anode grid. Further compacted electrolytic conductor fills the openings in the insulator.

Cathodic protection system and method for above-ground storage tank

Offshore or onshore electrical surveys of buried or submerged structures such as pipeline are conducted in a fixed-cell-to-moving-cell fashion either before or after one or more established pipe-to-electrolyte potentials can be obtained. The results of the fixed-cell-to-moving-cell survey are then corrected by a summation of the fixed-to-moving-cell recorded potential and the established potential at the location of the established potential to obtain a reliable electrical survey of the structure. As indicated, the fixed-cell-to-moving-cell survey may be conducted either before or after the established potential is obtained or either before or after a disposable wire survey using a direct connection to the structure.

Method and apparatus for electrical surveys of subsurface structures

A tubular anode such as tubular cast iron, magnetite, graphite, carbon or steel may be provided with an easily made internal or center connection having assured uniform resistance characteristics by the employment of at least two diametrically opposed wedge blocks, such blocks having parallel crowned and serrated contact surfaces and a wedge surface interface, such interface including a tongue and slot connection between the blocks, one or both blocks having oppositely extending tubular crimpable lead connections. The blocks may be made of malleable material so that when assembled and placed in the proper location inside the anode, one may be held while the other is driven axially, or both may be driven in axially opposite directions easily to form an electrical connection of assured electrical resistivity.

Anode and connection

An electrical survey of buried structures such as underwater or underground pipelines utilizes the steps of connecting one end of an economically disposable wire from a wire supply to the structure, either directly or through a heavier lead, the opposite end being electrically connected to a cell. The cell is moved along the structure together with a wire supply and a meter to obtain periodic measured structure-to-electrolyte potential values. If the wire is accidentally or intentionally disconnected during the survey, a stationary electrode is positioned at the wire break or last valid measured reading, such electrode being reconnected to the free end of the wire from the supply. The survey then continues periodically obtaining electrode-to-cell potential values. A structure-to-electrolyte potential profile is obtained by summing the last valid recorded structure-to-electrolyte potential value with each electrode-to-cell values. The summing may be done after the survey is completed by computer.

Electrical surveys of underwater or underground structures with

A reference cell for conducting closely spaced buried structure-to-soil electrical surveys uses a soil contact cell adapted to be mounted on the lower end of a pole or cane to be held by the surveyor walking over the right-of-way of the buried structure such as an underground pipeline. The cell includes a fluid chamber on the lower end of the pole or cane and includes on the lower end of the chamber a ground contact pad. A spring loaded bottom wall or boot closes the chamber and is operative to reduce the volume of the chamber when the lower end of the chamber is forced by the pole into contact with the ground above the buried structure. The reduction in volume of the chamber forces fluid through the contact pad to the ground to insure good electrical contact. Fluid in the chamber may be continuously replenished by a make-up supply carried by the surveyor which is drawn from the supply by return of the boot to its unstressed state. The ground contact pad may be porous and/or provided with a fluid flow opening which is opened when the pad is forced against the ground.

Low resistance, fluid replenishing, reference cell and method for using

An anode having an elongated body which may be extruded contains a bore extending at least partially through the body. The bore has an intermediate portion between the ends of the anode. A lead wire in the bore is fastened to a connector member having a self-tapping thread engageable at predetermined torque with the surface of the bore at the intermediate portion for cutting a thread in the bore upon relative rotation of the connector member and the body of anode material. A sealant is inserted in the bore after a thread is cut in the bore and surrounds the left in place connector member preventing moisture from reaching the connection to the anode at the intermediate portion.

Anode and method of construction

A cathodic protection system and method for steel reinforcement in concrete structures such as bridge decks, parking garage decks and highways utilizes platinized niobium or like metal wire anodes strategically positioned adjacent the concrete in a matrix of conductive carbonaceous material. The anode and matrix are preferably positioned in slots saw cut in the concrete surface avoiding the disposition of a conductive and wear resistant surface overlay which is not only expensive but which may exceed the design limitations of the structure. An impressed protective cathodic protection current is provided between the anodes and the steel of the structure. At places where the anode crosses in close proximity to reinforcing steel which may be exposed by the slot, or at places where cathodic protection current is not desired, a plastic sleeve may be placed over the anode. The anode may be connected directly to a current source or it may be spliced to an insulated copper lead wire and be brought down through the deck of the structure to be connected to the rectifier beneath the deck. Although more than one anode may be connected to any single rectifier circuit, it is preferred to have as many individual circuits as practicable to assist in analyzing the system performance with either permanently installed reference electrodes or portable reference electrodes.

Growing community of inventors

Medina, OH, United States of America

James B Bushman