Time filter

Source Type

Rivera H.,Autonomous University of Mexico State | Canto J.,Autonomous University of Mexico State | Martinez-Dela-Escalera L.M.,Autonomous University of Mexico State | Godoy A.,Autonomous University of Mexico State | And 3 more authors.
Journal of Corrosion Science and Engineering

We report the engineering work and numerical modeling for the complete diagnosis and refurbishing of the cathodic protection system for the largest dry dock in Mexico. The dry dock is located in the shore of the Gulf of Mexico at Tampico City and it is capable of serving ships as long as 250 meters. South bound this dry dock is the largest ship repair facility all the Atlantic coast until Panama. We report results of an overall diagnosis of corrosion damages of sheet piling, reinforced concrete, and pilings. Also we report an overall surface and underwater polarized potential measurement mappings. The cathodic protection of the dry dock components was fully redesigned. A complete new design was proposed to accomplish a sound distribution of impressed current anodes all along the steel sheet pilings, and the "dolphin" pilings. At the "dolphin" a new design for the anode support and its protection was developed. One of its main features of the anode supports is the allowance of 90° of bending freedom so the anodes supports could move and return to their intended position when impacted by the forest and waste debris usually present at the Pánuco River delta. © 2011 University of Manchester and the authors. Source

Godoy A.,Autonomous University of the State of Morelos | De Silva-Munoz L.,Electric Research Institute of Mexico | Rubi F.,Corrosion y Proteccion Ingeneria | De Leon Ibarra A.,Corrosion y Proteccion Ingeneria | And 4 more authors.
NACE - International Corrosion Conference Series

The new integrity management standard will be operating for main pipelines in Mexico. In order to achieve that standard, a new methodology was developed where different variables and models of Geographic Information Systems (GIS) were combined in a geodatabase capable of identifying hot spots for corrosion on pipelines. Such geodatabase, integrated into GIS with a graphical user interface, facilitates data review when performing preassessments on an External Corrosion Direct Assessment campaign. Using multilayer systems from the Mexican Institute of Geography, factors influencing the corrosion rate of buried hydrocarbon pipelines can be visualized. Variables like soil pH, porosity, salinity, temperature, humidity, resistivity, redox potentials, and bacteria concentration can be categorized in order to estimate the likelihood of pipeline corrosion or soil corrosivity at a given area. In order to represent the physical-chemical properties of the soil, these are converted to a raster data format (data model in which geographic entities are represented by pixels arranged forming a grid, with many bands of data). This conversion discretizes continuous variables in order to render them easier to manage visually and mathematically. Data obtained from Close Inspection Survey (CIS), Direct Current Voltage Gradient (DCVG), Alternate Current Voltage Gradient (ACVG), and In-Line Inspection (ILI) studies can also be integrated to the database allowing more complete corrosion likelihood, and risk assessments. © 2011 by NACE International. Source

Canto J.,Corrosion y Proteccion Ingeneria | Martinez-Dela-Escalera L.M.,Corrosion y Proteccion Ingeneria | Godoy A.,Corrosion y Proteccion Ingeneria | Rubi F.,Corrosion y Proteccion Ingeneria | And 4 more authors.
NACE - International Corrosion Conference Series

Vandalized rectifiers, anode beds, wirings, and power transformers are common causes of cathodic protection (CP) failure and corrosion problems for Mexican pipelines. The cost of replacing vandalized rectifiers, ground beds, cables and transformers, and the resulting corrosion damage to pipelines has a serious economic impact. In recent years, vandalism has increased being hammer and chisel the main tools employed by vandals. In order to deter this kind of actions, a novel approach is needed for the protection against vandalism for CP systems. Concealing, dissuading, alerting, and strengthening are the key conceptual basis of a set of devices and strategies that were developed to protect CP components in socially hostile environments. We present the design of a double layer reinforced concrete bunker for the protection of deep anode bed top sections providing multiple vents for anodic reaction products, alarm wiring, and a cavity for manual measuring of the anode current. For rectifier protection, a system was developed in order to conceal and protect a rectifier under the floor level, where it can only be drawn out employing a magnetic handle. Finally, the use of plastic instead of concrete for pipeline CP system test stations was proposed along with high impact signs that better communicate the dangers of excavating on pipeline right of ways. © 2011 by NACE International. Source

Maya E.,Corrosion y Proteccion Ingeneria | Martinez L.,Corrosion y Proteccion Ingeneria | Martinez L.,National Autonomous University of Mexico | Martinez-Dela-Escalera L.M.,Corrosion y Proteccion Ingeneria | And 5 more authors.
NACE - International Corrosion Conference Series

The corrosion damage in reinforced concrete structures, cause enormous economic losses worldwide. Concrete structures in oceanic ports and piers are exposed to a series of physical and chemical processes that can cause the rapid deterioration of both concrete and steel rebars. Such structures must receive special attention by performing periodic assessments of their structural integrity and by installing cathodic protection systems. The present paper describes the sequence used to evaluate the corrosion of a reinforced concrete structure that crowned the sheet piling of the commercial pier of Puerto Quetzal in Guatemala. Repair and corrosion protection methods and strategies are also described. © 2011 by NACE International. Source

Rivera H.,Corrosion y Proteccion Ingeneria | Mares C.,Corrosion y Proteccion Ingeneria | Canto J.,Corrosion y Proteccion Ingeneria | Lopez C.G.,PEMEX | And 5 more authors.
NACE - International Corrosion Conference Series

As a part of the Direct Assessment goals the knowledge of the problems allows a better decision process. In this way, the use of these methodologies for the evaluation of metal corrosion phenomena increases the possibilities of pipeline integrity analysis; one of these new techniques is the guided waves application. Certain maritime terminals for oil distribution in Mexico have been making efforts in order to get more information about the pipeline integrity of its network, and several cases have been studied with this methodology. Our group has participated as corrosion evaluation specialist and the experiences have shown the necessity of extra information about the technique and the involved variables, so we have improved laboratory exercises to get that kind of data. The evaluation of pipeline integrity with the guided waves technology has become in a very useful tool for non ILI susceptible pipelines. The success of this technique is based on the capability of a continuous surface evaluation. This technique is based in the induction of mechanical vibration on the pipeline, and the evaluation of the reflections generated by the defects in both internal and external surfaces. Because the guided waves are mechanical vibrations propagated through the pipeline, there are many factors involved in its attenuation, such as the pipeline geometry, coatings, the product inside the pipeline and the physical characteristics of the soil or the water if the pipeline is buried or submerged. Field experiences and laboratory tests performed using the Magnetostrictive technology, have been analyzed to determinate the effect of attenuation caused by some specific conditions of the pipeline, the environment and the operation parameters of the guided waves equipment. The application of the guided waves in operation docks in Northwest Pacific coast (Mazatlan), south Pacific coast (Acapulco) and southeast Gulf of Mexico (Lerma) where cases as generalized corrosion in external surfaces and pitting or certain coating types have represented a difficult for the technique application. These conditions have been reproduced in the laboratory to characterize the effect of this condition in the attenuation of the guided waves signal. In this work, we present evidence of the mentioned corrosion cases, which are determined by using the guided waves methodology; however we are focused to determine the effect of the different involved variables in the laboratory analysis, it means the consideration of parameters associated to the pipeline and to operational conditions. This combined analysis of both laboratory studies and site evaluations allow a complete reference about the capabilities of guided waves methodology and the perspectives for application in the pipeline network. ©2010 by NACE International. Source

Discover hidden collaborations