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The ductile fracture toughness of steel is used to assess the ability of a pipeline to resist long running ductile fractures in a burst event. With the introduction of modern low carbon clean steels with ultra high toughness, conventional measures of ductile fracture toughness (standard Charpy and DWTT energy) are under review, and alternatives are being studied. The crack tip opening angle (CTOA) was investigated to evaluate its appropriateness as a measure of modern pipeline steel ductile fracture toughness. At first, fracture mechanics tests at quasi-static rate were analyzed to examine the constancy of CTOA with crack growth. The results of this initial review are based on four pipeline steels with a range of ductile fracture toughness. The CTOA values are also compared with appropriate parameters from conventional tests to examine potential relationships that may be used to indicate the relative resistance of pipeline steels to ductile fracture propagation. The final objective is to compare CTOA values determined by the simple two specimen method and those developed through a formal fracture mechanics based technique.

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Traditional pipeline technology will be severely challenged as design-operating pressures continue to rise and gas field developments occur in more remote locations including the arctic. Cost-effective solutions to these issues can be found through innovative designs using new technology and its implementation. Some of these designs have considered the use of high-pressure natural gas pipelines resulting in the development of high strength steel. In order to meet these increases in pressure TransCanada and JFE/NKK have been working extensively on the application of X100 (Grade 690) linepipe and this has culminated in the construction and installation of a X100 project in the fall of 2002. This paper will discuss the development of the related research projects that allowed the successful completion of the field project. The topics will include the material properties and fracture control plans for X100. In addition the approach to strain based design for X100 will include the analysis for both the tensile strain limits (weld mismatch consideration) and compressive strain limits (i.e. buckling capacity). The development of the field welding process will also be covered. The paper will discuss the implications of using X100 from the perspective of the successful field project and the application of a strain-based design.

This paper presents a successful demonstration of application of neural networks to perform various data mining functions on an RB211 gas-turbine-driven compressor station. Radial basis function networks were optimized and were capable of performing the following functions: (a) backup of critical parameters, (b) detection of sensor faults, (c) prediction of complete engine operating health with few variables, and (d) estimation of parameters that cannot be measured. A Kohonen SOM technique has also been applied to recognize the correctness and validity of any data once the network is trained on a good set of data. This was achieved by examining the activation levels of the winning unit on the output layer of the network. Additionally, it would also be possible to determine the suspicious, faulty or corrupted parameter(s) in the cases which are not recognized by the network by simply examining the activation levels of the input neurons.