As Pipe Stress Engineers, we all, in some way or other, have handled the assignment of modeling and analyzing parallel lines routed over pipe racks or sleepers. Often these lines require Expansion Loops to have flexibility. However, although maybe routed kilometers, these lines often do not have any interconnection between them. Therefore, normal practice is to model these lines in separate \u2018.C2\u2019 files and carrying out stress analysis and expansion loops sizing and positioning separately. Now, suppose if we could model all lines running parallel to each other in a corridor and with same design code (e.g. B31.3) in a single \u2018.C2\u2019 file, then not only we could view and review all the lines together, also we could size and locate expansion loops for each line with respect to the others. This would not only reduce the modeling and analysis efforts but would also enable us to handle a lesser number of CAESAR II native files.\n\n\n\nThis is pretty well possible with the help of \u2018Block Operation\u2019 and \u2018Coordinate\u2019 features in CAESAR II. In my earlier post titled \u201cADVANTAGE OF USING \u2018BLOCK OPERATION\u2019 IN CAESAR II\u201c I have tried to explain \u2018Block Operation\u2019. In this post, I would attempt to highlight the effective use of the \u2018Coordinate\u2019 feature.\n\n\n\nLet us take the case of two lines running parallel to each other over a Pipe Rack, and supported on the same locations.\n\n\n\nParameters for Line 1:\n\n\n\nDesign Code = ASME B31.3MOC = ASTM A106 Gr. BSize = 12\u201dSch. = STDCorrosion Allowance = 1.5 mmDesign Pressure = 1200 kPa(g)Design Temperature = 175OCFluid Density = 900 kg\/m3Insulation = Mineral WoolInsulation Thickness = 50 mmCladding Thickness = 0.7 mmCladding Density (Aluminium) = 2700 kg\/m3\n\n\n\nParameters for Line 2:\n\n\n\nDesign Code = ASME B31.3MOC = ASTM A106 Gr. BSize = 10\u201dSch. = STDCorrosion Allowance = 1.5 mmDesign Pressure = 1800 kPa(g)Design Temperature = 150OCFluid Density = 900 kg\/m3Insulation = Mineral WoolInsulation Thickness = 50 mmCladding Thickness = 0.7 mmCladding Density (Aluminium) = 2700 kg\/m3\n\n\n\nLet us assume these two lines are having a gap of 500 mm between centerlines.\n\n\n\nFirst we model Line 1 as per given parameters.\n\n\n\nFig. 1: Modeling of line 1\n\n\n\nLine 1 starts at Node 10 and ends at Node 370.\n\n\n\nNow, we invoke \u2018List Input\u2019.\n\n\n\nFig. 2: Invoking List Input in 凯撒二世\n\n\n\nThen, at the \u2018List Input\u2019 window, we select all elements, right-click, select \u2018Block Operation\u2019 and then select \u2018Duplicate\u2019.\n\n\n\nFig. 3: Duplicating Elements in 凯撒二世\n\n\n\nIn the \u2018Block Duplicate\u2019 window, under the \u2018Options\u2019 tab, we select \u2018Identical\u2019, under \u2018Insert Copied Block\u2019 tab, we select \u2018At End of Input\u2019, and input \u2018400\u2019 in \u2018Node Increment\u2019 box, and click \u2018OK\u2019.\n\n\n\nFigure - 4\n\n\n\nNow, we input \u2018500\u2019 in box of X coordinate in \u2018Enter Global Coordinates (mm.) for Node 410\u2019 under \u2018Global Coordinates\u2019 window.\n\n\n\nFigure - 5\n\n\n\nNow, we have created the geometry of Line 2, but still with parameters of Line 1. So, we change the parameters as applicable.\n\n\n\nFigure - 6\n\n\n\nFigure - 7\n\n\n\nThen, we close \u2018List Input\u2019 window.\n\n\n\nNow, we are ready with two lines which are running in same route, supported at same locations, but still requiring some manual modifications at elbows of Line 2.\n\n\n\nFigure - 8\n\n\n\nSo, we reduce the lengths of elements before and after the first elbow by 500 mm. Likewise, we adjust the expansion loop of Line 2 to arrive at the following geometry in Figure \u2013 9.\n\n\n\nFigure - 9\n\n\n\nFinally, we increase the lengths of elements before and after last elbow by 500 mm.\n\n\n\nFigure - 10\n\n\n\nThis completes the parametric and geometric adjustments of Line 2.\n\n\n\nNow, both of the lines are ready for onward analysis.\n\n\n\nNote: Although this is a useful and smart way of working, the stress analyst must use his\/her judgment for use of this feature, particularly if the lines are to be analyzed under different codes, it is recommended not to use this feature. Also, the model shown as an example is a very simplified one. An analyst may encounter more complex problems, and the extent of manual adjustment is likely to vary from little to more on a case by case basis.