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Corrosion of metallic water pipelines is a function of the pipe's surrounding environment (soil and water). This means that it is important to know the physical and chemical characteristics of the pipe's surrounding environment. The corrosion of externally unprotected metallic water pipelines, particularly ductile iron pipes, in localities with aggressive soil conditions is becoming a significant problem: repair and replacement costs are high, and failures cause supply interruptions to customers and inconvenience to the public. Anti-corrosive protection for metallic water pipelines, their fittings and accessories is very important, because they may be attacked by corrosion with time. The tendency of a metallic substrate to corrode is a function of the surface characteristics of the metal and of the metal/protective film interface, the physical, electrical and electrochemical properties of the film, and the nature of the environment in which the pipelines system is placed.In this work the authors have looked at the corrosion problems of metallic water pipelines and their control. The corrosive properties of water and soil environments are reviewed. Parameters affecting corrosion are discussed. The pollution of drinking water transported by metallic pipes caused by corrosion is discussed. The purpose of this work is to provide guidelines for materials selection in water and soil environments, and how the water pipelines can be protected against metallic corrosion. Keywords: corrosion of metallic water pipelines, drinking water pollution, corrosive water, metallic water pipes.

In the casting technology, defect free casting had been the primary goal since the inception of the technology. However in the present casting arena, emphasis on the precise and defect free casting has got greatly increased due to energy saving, environmental and economy considerations apart from the stringent product quality standard requirements. In order to achieve this level, computer simulation is inevitably necessary. FEM based simulation software is used to find solidification related defects specially shrinkage porosity very precisely. In the present work ANSYS, an FEM based versatile software has been used for hot spots identification in a two feeder system. The feeders have been designed and optimized. ANSYS has been used for transient thermal analysis and then optimization process has been performed. Path of two feeder optimization for steel sand casting on ANSYS have been searched. Conductive and convective heat transfer has been taken in to consideration. The whole process is performed using traditional modulus approach also. The results are compared. The comparison reveals that ANSYS optimizer provides better results for casting having two feeders. It saves material and energy thus resulting into economy and environmental benefits too. Hence it may be recommended as superior over modulus approach for two feeder system in sand casting.