Simulated Service Evaluation of Marine Coatings

1967 ◽  
Vol 4 (02) ◽  
pp. 189-195
Author(s):  
R. P. Devoluy ◽  
L. J. Nowacki ◽  
F. W. Fink
Keyword(s):  
Protective Coatings ◽  
Surface Preparation ◽  
Service Evaluation ◽  
Control Surface ◽  
Good Test ◽  
Electrical Currents ◽  
Marine Coatings ◽  
Service Conditions ◽  
Evaluation Techniques ◽  
Reliable Methods

There is a strong demand for faster, and yet reliable, methods of evaluating new protective coatings for underwater marine service. Many of the new materials are so durable that it is impractical to await the outcome of the traditional methods of testing panels in tropical waters. Furthermore, stationary panel exposures in sheltered waters often omit the service conditions that are the controlling causes of failure. For underwater coatings these variables may include exposure to electrical currents (cathodic protection),abrasion, impact, impingement, cavitation, and other velocity effects. Coatings tests applied to ships are costly to install. They are also prone to accidental damage, and subject to carelessness or overly protective attention. Moreover, it is difficult to control surface preparation, application, and climatic variables well enough to make a fair comparison between coating systems. Finally, they take so long that more promising materials are often available before the program is completed. This paper describes some of the proven techniques for simulating marine service and suggests their use to parallel more closely actual conditions that coatings encounter in marine service. The criterion for a good test is that it predict the order of performance of a number of coatings in the service for which they are intended. Proposed simulated service evaluation techniques must first be checked with coatings of known performance for that service. It is important that the coatings fail in laboratory studies in the same way as in actual service. Thus, the performance of new coatings can be related to the performance of the known coatings.

scholarly journals Chemical Degradation and Color Changes of Paint Protective Coatings Used in Solar Glass Mirrors

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 476
Author(s):  
Mohamed Guerguer ◽  
Sanae Naamane ◽  
Zineb Edfouf ◽  
Olivier Raccurt ◽  
Hassan Bouaouine
Keyword(s):  
Protective Coatings ◽  
Natural Aging ◽  
Attenuated Total Reflection ◽  
Chemical Degradation ◽  
Complete Analysis ◽  
Color Changes ◽  
Colorimetric Measurements ◽  
Marine Site ◽  
Service Conditions ◽  
Paint Coatings

This paper reports a study of the influence of outdoor natural aging on paint coatings applied to the back of three commercial solar glass mirrors (A1, C2, and D2) under two different exposure environments (marine and desert) in Morocco for a period of about three years. The aging assessment was carried out through colorimetric measurements and FTIR-ATR (Attenuated total reflection-Fourier transform infrared) analyses of the top coat paints. The obtained results demonstrate that the tested coating system had a high resistance at the desert site. Under the desert environment, no obvious changes to the coating occurred after 350 days. However, at the marine site, some color changes were detected, and the coating got yellow and more matte, especially for mirror A1. FTIR-ATR analyses have indicated many modifications in the intensity of many bonds of infrared spectra especially for paint of this mirror type (A1). This chemical degradation is not only due to UV degradation but also related to many factors, such as humidity, salinity, and rainfall. This finding was concluded after the faster degradation observed on samples exposed at the marine site. The present study confirms the need to use different exposure environments for testing the limits of new protective systems for solar glass mirrors rather than using only the real service conditions. Finally, accelerated tests are necessary for understanding the effect of each degrading parameter and their results should be compared to outdoor tests data for a complete analysis of coatings durability.

scholarly journals Carboline’s systems approach to the maintenance of coating systems for steel structures in the oil and gas industry

2019 ◽  
Vol 121 ◽  
pp. 02003
Author(s):  
Gennadiy Konovalov
Keyword(s):  
Oil And Gas ◽  
Systems Approach ◽  
Protective Coatings ◽  
Surface Preparation ◽  
Steel Structures ◽  
Oil And Gas Industry ◽  
Internal Stresses ◽  
Gas Industry ◽  
Low Levels ◽  
Protective Systems

The article discusses options for optimal repair systems with several advantages compared with competitive solutions in the market of protective coatings. The proposed materials have a high tolerance to the degree of surface preparation, compatibility with old protective systems, as well as low levels of internal stresses arising in the repair layer of coating, which significantly reduces the risk of pulling off the old protective coatings after repair.

scholarly journals ENHANCING PERFORMANCE CHARACTERISTICS OF EQUIPMENT OF SEA AND RIVER TRANSPORT BY USING EPOXY COMPOSITES

Transport ◽  
2016 ◽  
Vol 31 (3) ◽  
pp. 333-342 ◽  
Author(s):  
Andriy Buketov ◽  
Pavlo Maruschak ◽  
Oleksandr Sapronov ◽  
Dmytro Zinchenko ◽  
Vitaliy Yatsyuk ◽  
...  
Keyword(s):  
Impact Toughness ◽  
Silver Oxide ◽  
Filler Content ◽  
Protective Coatings ◽  
Physical And Mechanical Properties ◽  
Environmentally Benign ◽  
Impact Loads ◽  
Maximum Capacity ◽  
Marine Coatings ◽  
River Transport

Coatings based on epoxy diane oligomer ED-20 are being developed as environmentally benign, foulingresistant marine coatings. Silver oxide and carbonate (mixture) was used as filler, the dispersion of which is 0.5 µm. It is proved that for the formation of composites with the improved physical and mechanical properties it is necessary to add Mechanical Mixture of Silver Carbonate and Oxide (MMSCO) in the amount of q = 0.050…0.250 pts. wt. into the epoxy diane oligomer ED-20 (100 pts. wt.). The obtained values of impact toughness of composites during the introduction of MMSCO into the binder increased by 2.5 times compared to the epoxy matrix. Moreover, the maximum capacity to resist impact loads, including fracture toughness, was demonstrated by the Composite Material (CM) with the filler content q = 0.050 pts. wt. Impact toughness of this CM is а = 18.53 kJ/m2. The developed materials and protective coatings based on them were used on the dry cargo ship Oles Honchar.

Fitness for Service Assessment of the Thermal Sleeve Weld Failure for Steam Generator Reheat Condensate Nozzle in CANDU6 Nuclear Plant

2011 ◽  
Author(s):  
Reza Ghafouri-Azar ◽  
Alice Sze ◽  
Dan Vlaicu ◽  
Mike Stojakovic
Keyword(s):  
Heat Transfer ◽  
Steam Generator ◽  
Structural Integrity ◽  
Convection Heat Transfer ◽  
Internal Surface ◽  
Service Evaluation ◽  
Nozzle Design ◽  
Thermal Shield ◽  
Weld Failure ◽  
Service Conditions

An assessment was completed to address the failure of internal thermal sleeve weld for reheat condensate nozzle of steam generators. The plant is operated by Ontario Power Generation (OPG) in Pickering, and has CANDU®6 type reactors. The objective of assessment was to evaluate the effect of the failed weld on the overall structural integrity of the nozzle for the defined operating service conditions. The fitness for service of the steam generator nozzle was demonstrated by comparing the maximum stress ranges of the initial nozzle design with the failed weld nozzle configuration under the same service conditions. Two nozzle configurations were considered for this assessment. One configuration represents the original shape with no leakage at weld indicating as-designed condition. Transient heat transfer and the stress analyses were performed according to the defined service limits. Another configuration completed for the faulty condition in which weld is failed and thermal sleeve separated. The same transients as the first configuration were applied, but the leakage was introduced at the thermal sleeve weld. The effect of leakage was considered by changing the convection heat transfer coefficient in annulus area between the external side of sleeve and internal surface of the nozzle. Critical locations on the nozzle were identified for the whole transient cycles, and assigned different stress lines. The maximum and minimum stress intensity ranges of the initial nozzle design and the cracked weld nozzle design were compared for these stress lines. It was concluded that the thermal sleeve weld failure with the conservatively postulated leakage flow provides better results in terms of stress ranges compared to the as-design condition. The thermal shield was over constrained in as-design condition. And for the fitness for service evaluation in was decided to leave the failed weld in-service without repairing it.

scholarly journals Surface preparation as one of the main factors for ensuring the durability of anti-corrosion coatings

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Aleksei Bezgodov ◽  
Ilya Ovchinnikov
Keyword(s):  
Surface Treatment ◽  
Protective Coatings ◽  
Surface Preparation ◽  
Negative Consequences ◽  
Treatment Methods ◽  
Factors Affecting ◽  
Metal Structures ◽  
Optimal Processing ◽  
Main Factors ◽  
Paint Coatings

This article is devoted to the protection of bridge metal structures from corrosion. The article was written with the aim of studying one of the stages of anti-corrosion treatment, namely the preparation of the surface before applying a protective coating. In the article, the authors address the problem of the durability of paint coatings, and point to the main reasons, to a greater extent, affecting the service life. Studying the problem of the durability of protective coatings, the authors distinguish such a stage as preparing the metal surface of the bridge structure before applying the paintwork. The authors tell how important the preparation of the surface is and what negative consequences are possible if it is disturbed or not. For a more detailed study of the problem, the authors consider several methods of preparing the surface of the structure, such as: abrasive blast cleaning, phosphating the surface and heat treatment. When studying the above mentioned methods, the authors describe the technology of the work, the main factors affecting the final result of processing, as well as the positive and negative sides of each of the methods. For each of the surface treatment methods, the authors present illustrations that clearly show the basic concept of the selected treatment option. Summing up the comparative analysis of surface treatment methods before applying anti-corrosion coatings, the authors chose the most optimal processing method, as well as concluded that the importance of this stage and the possibility of its further improvement.

Outer Cover Damages on Flexible Pipes: Corrosion and Integrity Challenges

2014 ◽  
Author(s):  
Morten Eriksen ◽  
Knut Inge Engelbreth
Keyword(s):  
Early Detection ◽  
Pipe Wall ◽  
Confined Water ◽  
Integrity Assessment ◽  
Corrosion Rates ◽  
Flexible Pipes ◽  
Hole Configuration ◽  
Outer Cover ◽  
Service Conditions ◽  
Reliable Methods

According to published statistics for flexible pipes, penetrating holes in outside covers of flexible pipes is one of the most frequent damage mechanisms. The corrosion and fatigue performances of tensile and pressure armour wires are directly influenced by the fluids in the pipe wall annulus. There are several incidents where cover damages have led to serious pipe failures. In this perspective the best strategy is to avoid cover damage, but for those cases where damage occurs it is essential to have systems in place for early detection, as well as capabilities for repair. Holes in the outside cover can create a range of different conditions in an annulus depending on location of the hole, configuration of the pipe and service conditions. CO2 driven corrosion in a confined water filled annulus has been investigated extensively and reported by several authors to give very low corrosion rates. However, the environments that armour wires are exposed to in certain parts of an annulus may differ significantly from confined water with CO2. One obvious example is the region around a penetrating hole in the outer cover where there may be repeated ingress of oxygenated seawater or air that mix with CO2 in the annulus. Such environments could cause high corrosion rates that may explain some observed failures. In many cases it is difficult to quantify the annulus environments precisely and suitable corrosion models have not been established. The consequences are large uncertainties in the prediction of corrosion type and rate, giving challenges for integrity assessment. This paper will identify and discuss unresolved corrosion issues related to outer cover damage linking it to field experience. Needs for developing further knowledge and models will be addressed. Efficient and reliable methods for repair of outer cover damage that can be mobilized soon are essential for restoring the integrity of pipes with damages to outer covers.

Investigation of the Properties of Heat-Protective Coatings to Improve the Performance of Products

2021 ◽  
Vol 1037 ◽  
pp. 516-521
Author(s):  
Vladislav Smolentsev ◽  
Nikolay Nenahov ◽  
Natalia Potashnikova
Keyword(s):  
Combustion Chamber ◽  
Protective Coatings ◽  
Rocket Engine ◽  
Multilayer Coating ◽  
Surface Preparation ◽  
Rocket Engines ◽  
Initial Surface ◽  
Technological Parameters ◽  
Materials Used ◽  
Liquid Rocket

The heat-loaded part of the combustion chamber of a liquid rocket engine are Considered. The proposed coating has several layers: an internal metal coating that contacts the part or substrate, and an external coating made of a mixture of ceramic granules and metal powder. At the same time, to obtain the initial surface for coating with the required surface layer roughness, it is proposed to use the method of sand blasting. The article analyzes possible mechanisms of material formation for "base-coating" transition zones, as well as the influence of their chemical composition on the adhesive strength of layers.. The choice of brand and combination of materials used for coating is justified. Technological modes that have been tested in production conditions when applying heat-resistant coatings to parts of modern rocket engines are proposed. The influence of technological parameters of the initial surface preparation process and the geometry of the resulting micro-relief of the substrate on the adhesion characteristics of a multilayer coating made of heat-protective materials operating in the high-temperature zone of the combustion chamber of liquid rocket engines is revealed.

Protective Coatings Offshore: Introducing a Risk-Based Maintenance Management System—Part 1: Risk Analysis Methodology

CORROSION ◽  
2009 ◽  
Vol 65 (12) ◽  
pp. 809-816 ◽  
Author(s):  
S. B. Axelsen ◽  
O. Ø. Knudsen ◽  
R. Johnsen
Keyword(s):  
Risk Analysis ◽  
Management System ◽  
Protective Coatings ◽  
Surface Preparation ◽  
Maintenance Management ◽  
Analysis Methodology ◽  
Maintenance Program ◽  
Offshore Installations ◽  
System Part ◽  
Maintenance And Inspection

Abstract This paper summarizes the risk analysis methodology and challenges related to the establishment of a risk-based maintenance management system for protective coatings. Maintenance of protective coatings offshore is demanding on resources and costly. Initial selection of a coating system and the quality of the application work, including surface preparation, are vital elements for securing an acceptable coating lifetime. Most offshore installations will require, however, maintenance of the protective coatings due to degradation and/or mechanical damages. Development and implementation of a maintenance program for coatings is therefore an essential part of the overall maintenance programfor these installations. A complete maintenance program development includes: 1) establishment of coating quality status through inspection, 2) preparation of a maintenance program/strategy, and 3) preparation of detailed maintenance plans and job packages/descriptions. Optimization of maintenance and inspection programs through risk analysis is used frequently by the industry today. This principle can also be used for coating maintenance. Since the risk picture can be described by scenario, frequencies, and consequences, risk could be expressed as a function of coating status and a consequence of a coating damage. Based on this assumption, a systematic approach for optimization of the maintenance program has been developed.

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