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.
