auto sketch 9 isometric piping symbol library

Therefore, the abbreviation FOB in the note instructs the fabricator how to install the reducer.įigure 3.49. In the example in Figure 3.43, the reducer is to be installed with its flat side on the bottom. When representing the reducer on a drawing it is necessary to include a note that identifies the reducer’s size and type, as well as its orientation. Therefore, an eccentric reducer is used in pipe racks to maintain a constant Bottom of Pipe (BOP) (see Figure 3.43). The small end will not have a diameter large enough to touch the steel supports. But if that pipe changes its pipe size while in the pipe rack, it will not rest on all the steel supports. For example, when a pipe is routed through a pipe rack, it naturally will rest on the steel beams and will be supported throughout its length. There are specific situations where the eccentric reducer must be installed with its flat side on the top, or the flat side on the bottom of the fitting. Conversely, the eccentric reducer has offset centerlines that will create a flat surface on either the top or the bottom of the fitting, depending on how the fitting is rolled prior to welding. The concentric reducer maintains the same centerline through both the large and small ends of the fitting. The differing characteristics of these two reducers are quite noticeable.

Auto sketch 9 isometric piping symbol library