Steam systems pipe design and pipe stress analysis

Pipelines are used for transporting gas and liquid fluids in very wide areas and at very different pressures and temperatures. While working on pipelines, we try to find solutions to three important problems. These; determining the optimum pipe diameter, determining the optimum insulation thickness and taking the stresses in the most economical way. Pipe Design mainly depends upon stress analysis. Process pipelines and power pipelines are checked by pipe stress engineers to verify that the permissible values are not exceeded in the case of different loads such as continuous loads, operating loads, pressure tests, permissible pipe tension, positioning, nozzle loads, hangers and supports are correctly positioned and selected. Pipelines that are used for the transportation of liquid, steam and air in many factories are regulated by Industrial/International codes and standards. Pipe line systems consist of pipes, flanges, gaskets, elbows, valves and various couplings. ASME B31,1 stipulates the minimum requirements for typical pipe systems design, material, assembly, test, control operations and maintenance in stations producing electrical energy, industrial and institutional installations, geothermal heating systems, central and regional heating and cooling systems. In this master thesis, stresses formed in pipelines and their causes, effects of pipe design on these stresses, causes and effects of pipe displacements and work flow for pipe stresses are investigated and a general criterion for pipe stress analysis is aimed to be specified. By taking pipe stress into account, also a basic and general criterion for pipeline design is aimed to be determined. In the analysis part of this study, stresses formed in pipelines, hydrostatic loads, continuous loads, loads formed during the operation or that arise during the course of heat expansion and load and moment values of the turbine connection, of two different designs of a turbine steam line which belongs to a powership, are calculated using finite elements method with the help of programme, their model design convenience are examined and optimization of the systems practised. During the calculations ASME B31.1 code standards are taken into consideration. Key words: Pipeline design, Pipe stress, Pipe stress analysis, ASME B31.1