Corrosion Modeling Solutions Showcased at NACE 2014
BEASY participated in a very busy NACE Corrosion Conference in San Antonio last month. We were active in the conference program and exhibition hall, highlighting corrosion modeling services and software. It was good to see many friends and interested engineers visiting us at our booth. There were a number of papers presented during the Technical Program which featured some engineering projects carried out by the BEASY engineering services team and by customers.
Improved Effectiveness Of Direct Assessment Field Surveys Through The Application Of Boundary Element Analysis (BEA) To Simulate Electrical Field Interference Between Collocated Pipelines. Katurah Hansen, Angel R. Kowalski, Shane Finneran, Jason Land. Det Norske Veritas (USA), Inc.
Direct Assessment above ground surveys are often time consuming, laborious, expensive and require operational knowledge of NACE Standard TM0109-2009. The use of boundary element analysis (BEA) software allows for a more comprehensive re-creation of different possible conditions and can provide additional analysis to validate survey results when conditions, such as buried metallic structures adjacent to the pipeline being assessed limit the sensitivity of the survey tools. This combined use approach offers the benefit that a simulation model can be developed that fits well to the actual conditions of the pipeline, with minimal assumptions.
To evaluate the effectiveness of the designed CP System, a boundary element analysis (BEA) was performed to analyze the predicted potential distribution and current density for the natural gas pipeline collocation. The interfering current makes it difficult to accurately calculate these distributions by other methods. Results from the BEA allow for current shielding, over potential hot spots, and other critical areas where the CP is least effective, to be identified.
ICCP System Design on the Hull of an Ice Breaker by Computational Analysis. Min-Jung Lee, Chae-Seon Lim. Samsung Heavy Industries Co., Ltd
Impressed current cathodic protection (ICCP) systems have been employed with coatings to prevent corrosion on the hulls of ice breakers. Many ICCP systems used for commercial vessels are designed based on the designer's experiences rather than by analytical method. The purpose of this paper is to simulate the performance of ICCP systems on hulls under Arctic conditions by a computational analysis based on boundary element methods (BEM) and to deduce an optimized design. For this purpose, an Arctic shuttle tanker that will travel across the Barents Sea was investigated. The coating breakdown factors at the end of the design life were assumed to range from 1% to 5% depending on the ice strengthening areas of the hull. The design optimization process consisted of a series of calculations of the structure potential with several cases of ICCP system arrangements and reference cell target potentials. The effects of these factors were studied under Arctic conditions.
The model predicted the potential distributions on the hull and the results were used to determine the optimized design of the ICCP systems under the service conditions.
Image: Coating damage on the hull of an Arctic vessel after 2.5 years under Arctic Sea
The Application Of Computer Modeling To Improve The Integrity Of Ballast Tanks. Robert Adey, Guy Bishop, John Baynham, CM BEASY Ltd
Generally additional cathodic protection (CP) systems are installed in ballast tanks to provide protection to the areas that may become unprotected by degraded coatings. Because of the complex geometry of the tanks and the presence of pipework, equipment and in some cases ladders and walkways the correct placement of both sacrificial & ICCP anodes is essential to get a good potential distribution that ensures no areas are either under or over protected.
Computer modeling has become widely used in the maritime corrosion industry to predict the performance of CP designs and to ensure adequate protection is provided to the structure over its life. In this paper a case study is presented where computer modeling is used to verify and optimize the design of the corrosion control system of a ballast tank and to predict how it will perform over the service life of the tank. Case studies are presented for both a sacrificial CP system and ICCP design.
Image: Optimized anode layout showing initial consumption rates