Laying out for boiler makers and sheet metal workers; a practical treatise on the layout of boilers, stacks, tanks, pipes, elbows, and miscellaneous sheet metal work . on upon the cj-linder. Lay out the line AB, , equal to the length of the circumference of the base of thecylinder and divide it into the same number of equal partsinto which the base was divided; in this case twenty-four asthe semi-circumference was divided into twelve equal lines at right angles to AB at these points and lay offalong them the lengths of the corresponding lines in Fig. each base of the cyl
Laying out for boiler makers and sheet metal workers; a practical treatise on the layout of boilers, stacks, tanks, pipes, elbows, and miscellaneous sheet metal work . on upon the cj-linder. Lay out the line AB, , equal to the length of the circumference of the base of thecylinder and divide it into the same number of equal partsinto which the base was divided; in this case twenty-four asthe semi-circumference was divided into twelve equal lines at right angles to AB at these points and lay offalong them the lengths of the corresponding lines in Fig. each base of the cylinder is at right angles with theaxis as in Fig. 7, all of these lines are equal so the developedsurface will be a rectangle. If the base MA had been inclinedas MA, then the length of each of the parallel lines would THE SUBJECT OF LAYING OUT II have been different and it would have been necessary to meas-ure each Hne separately and lay it out on the correspondingline in the development. Then the bottom edge of the de-veloped surface would have the form shown by the dotted linein Fig 8, the numbers showing the corresponding lines on thecylinder and OUTSIDE FIG. 9. Before taking up the actual layout of a cylindrical boileror tank shell, the apprentice must first be able to find thecircumference of a circle in order to get the length of theplate corresponding to the distance AB in Fig. 8, as this linewas made equal to the length of the circumference of the base times its radius squared. The use of such tables will greatlyreduce the labor of computation and the chances of makingmistakes. As the material used in boiler construction has considerablethickness, it will be apparent that when a plate is rolled upin the form of a cylinder, the diameter at the inside of theplate is less than the diameter at the outside by twice thethickness of the plate; therefore, the circumference corre-sponding to the inside diameter will be considerable less thanthat corresponding to the
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Keywords: ., bookcentury1900, bookdecade1900, bookidl, booksubjectsteamboilers
