Corrosion Of Cable Sheaths Research Articles

Effects of magnetic field on cable sheath corrosion

This article presents the results of research on the effects of utility-frequency magnetic fields on aluminum sheath corrosion of three-phase power cables in a 3 wt% NaCl aqueous solution. Various conditions were considered, including rotating and pulsating magnetic field and connection of the cable to a high-voltage source to research the degradation of aluminum sheath under conditions close to real operation. Influence on surface morphology was evaluated through scanning electron microscopy, energy-dispersive spectroscopy, and X-ray crystallography. Chemical analysis of NaCl solution samples was used to determine how aluminum concentration changes over time, demonstrating the effects of magnetic field. Influence of magnetic field on the evolution of field-gradient force near the sheath was also researched.

Corrosion of Lead Sheath In Manhole Water—A Contribution to the Work of NACE Technical Unit Committee T-4B(1), on Corrosion of Cable Sheaths★

Abstract Tests were made in 45 selected manholes in Tokyo by attaching lead coupons to cable sheaths in the manholes and submerging coupons in the manhole water. Potentials of the lead sheaths to ground were measured to each test point. Samples of water from each manhole were tested and mean values compiled. Corrosion losses by weight were measured at 100 and 240 days. These showed losses to be proportional to potential difference between cable and ground. Pitting was found where potential to ground was more than 100 mV. No relationship between weight losses and water composition could be determined because of varying potentials to ground. Laboratory tests were conducted with coupons subjected to uniform current densities so the influence of water composition could be weighed. Conclusions were: Water with more chlorides was most corrosive. Under cathodic corrosion conditions, loss was less than 1/10 that under anodic conditions but pH has greater importance. Under anodic conditions water composition is more significant. Under negative potentials tests coupons were evaluated under varying concentrations of chlorides. Current density continued to be the most significant variable while pitting was more pronounced with additions of chlorides up to 50 ppm but somewhat less when amounts greater than this were added. 7.7

A Concentrator For Coordinated Corrosion Testing—A Contribution to the Work of NACE Technical Unit Committee T-4B on Corrosion of Cable Sheaths(1)

Abstract A concentrator for coordinated corrosion testing is described with which 19 simultaneous voltage readings can be made and which requires only one suitable voltmeter. The test box contains nineteen 4 mf capacitors, each of which accepts a charge from one of the external test circuits. At the desired instant of testing, the external circuits are all disconnected from the capacitors by the opening of gang-type relays. The voltage standing on each capacitor is then the corresponding voltage of the particular external circuit at the instant of disconnection. By means of a rotary switch, these voltages can be taken off in sequence and read out on a suitable external voltmeter at the convenience of the observer. The advantages derived from the use of the test box are as follows: (1) One meter observer can duplicate the work of up to nineteen observers on a meter-per-circuit basis; (2) One accurate voltmeter, having a high input impedance, can be selected for use rather than using an assemblage of 19 meters; (3) Despite fluctuation in measured voltages, the data obtained are more accurate than ordinarily can be obtained by direct readings of a meter on a test circuit; (4) The readings are truly simultaneous; (5) The use of one observer and one meter avoids variances formerly introduced by human characteristics and meter dissimilarities. 4.5.3

Lead Cable Sheath Corrosion Under Cathodic Protection Conditions

Laboratory tests were conducted to determine whether or not corrosion of lead cable sheath can, occur under cathodic protection conditions. Some of the runs were made in cells containing the aqueous solutions of chlorides or chlorides and alkali while other tests were made with the lead cable sheaths in contact with soil saturated with the various solutions. The results from all of these tests indicated that no corrosion of the cable sheath occurred in any of these environments so long as the cathode was receiving protective current. It was found, how-ever, that corrosion and pitting of lead cable sheath could occur when the protective current was interrupted. It was determined that the cathode products of previous cathodic protection constitute an environment for potentially serious corrosion at any time that the protective current ceases to flow to any part of the lead cable sheath. 5.2.1

Stray Current Electrolysis—Fifth Interim Report of Technical Unit Committee T-4B on Corrosion of Cable Sheaths*,, **

Abstract Data collected from 19 companies operating power and communication cables indicates that:Communication cables generally are bonded at each manhole.Communication cables may be bonded to other subsurface structures to equalize potentials. Fre-quently this follows joint electrolysis surveys when the installation is made after agreement is reached among the owners of affected plant. Local electrolysis committees are useful in these agreements.Bonding of power cables usually is done to prevent personnel hazard from fault currents, to insure low impedence path of fault current return, aid in corrosion control, reduce sheath losses on single-conductor cables and reduce noise in communication circuits. Size of bond wire is related to probable fault current. 3.6.9

Cathodic Protection of Lead Sheathed Cables In the Utilities Industry—A Report of NACE Technical Unit Committee T-4B on Corrosion of Cable Sheaths (Prepared by Task Group T-4B-2 on Cathodic Protection of Cable Sheaths)

Cathodic Protection of Lead Sheathed Cables In the Utilities Industry—A Report of NACE Technical Unit Committee T-4B on Corrosion of Cable Sheaths (Prepared by Task Group T-4B-2 on Cathodic Protection of Cable Sheaths)

First Interim Report of Technical Unit Committee T-4B On Corrosion of Cable Sheaths. Pipe-Type Cable Corrosion Protection Practices In the Utilities Industry

Abstract Data received in reply to a questionnaire is compiled on the actual field practices of utilities operating pipe-type cables. The data cover more than 90 percent of this type of cable in operation at the time the survey was made. The prinicpal data are tabulated, giving reports by seventeen operators on field practices. The subjects covered include size and kind of pipe, coating materials, holiday testing, potential surveys, cathodic protection, coating resistance measurements, rates of coating resistance depreciation, bonding, stray current measurements, shunts, surveys, voltages and magnitudes of cathodic protection currents and other information.

Report on the Activities of Technical Practices Committee 16 on Electrolysis and Corrosion of Cable Sheaths

Report on the Activities of Technical Practices Committee 16 on Electrolysis and Corrosion of Cable Sheaths

Cable Sheath Corrosion and Prevention

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation B. B. REINITZ; Cable Sheath Corrosion and Prevention. CORROSION 1 November 1953; 9 (11): 425–431. doi: https://doi.org/10.5006/0010-9312-9.11.425 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest Search

Objectives of TP-16, Electrolysis and Corrosion of Cable Sheaths

Objectives of TP-16, Electrolysis and Corrosion of Cable Sheaths

Telephone Cable Sheath Corrosion in Non-Stray Current Areas

Telephone Cable Sheath Corrosion in Non-Stray Current Areas

Study of A-C Sheath Currents and Their Effect on Lead-Cable-Sheath Corrosion

The destruction of lead sheaths on underground cables by electrolysis usually is caused by the action of direct currents which originate from one or several well-defined sources. Little information is available concerning a-c electrolysis, and since the extent of its destructive action is less widespread than that produced by direct current it is considered generally to be relatively less important in the field of cable-sheath corrosion. This paper discusses two cases of electrolysis in which the lead sheaths on single-conductor power cables were corroded through, causing cable breakdowns; and describes field observations and laboratory tests which show that at first the corrosive action was accelerated greatly by rectified alternating currents which were induced in the sheaths by the load current. A method of protecting the sheaths against such electrolytic corrosion also is described.

Cathodic Corrosion of Cable Sheaths

Cathodic Corrosion of Cable Sheaths

Cathodic Corrosion of Cable Sheaths

Single crystalline 4H-SiC is a wide-gap semiconductor with optical properties that are poised to enable new applications in microelectromechanical systems (MEMS) and quantum devices. A number of key hurdles remain with respect to the micro and nano-fabrication of SiC to prepare precise photonic structures with nanometer-scale precision. These challenges include development of a fast, scalable etching process for SiC capable of producing a sub-nanometer roughness semiconductor surface while simultaneously reducing the total thickness variation across a wafer. Our investigation into UV photoelectrochemical processing of SiC reveals high dopant-type selectivity and the advantage of multiple etch stops to reduce layer thickness variation. We demonstrate dopant-type selectivities >20:1 using a single step and a >100x reduction in surface variation by combining two etch stops. Moreover, the etch rate is fast (>4 μm/hr) and the etched surface is smooth (~1 nm RMS). These results demonstrate a scalable path to the fabrication of precise nanoscale SiC structures and electronic devices that will enable the next generation of MEMS and photonic quantum devices.

Formation of Lead Monoxide as a Cable Sheath Corrosion Product

Formation of Lead Monoxide as a Cable Sheath Corrosion Product

Cable sheath corrosion — Causes and mitigation

Cable sheath corrosion — Causes and mitigation

Cable Sheath Corrosion -Causes and Mitigation

The causes and mitigation of telephone cable sheath corrosion are dealt with in this paper, which describes particularly a method of applying a counter potential to the cable sheath for the mitigation of corrosion from localized currents. This method, although not new, has had but limited application. It may find extensive future use for controlling corrosion on intercity toll cables, and in localities where street railways have been abandoned. In addition to a unique application of this method, there is also described the method of correcting by current drainage a particularly bad case of corrosion from stray current.

Cable sheath corrosion causes and mitigation

Cable sheath corrosion causes and mitigation