The correct size Mixing Nozzle for a specific application is a function of injection flow rate and viscosity of the polymer melt. For approximate sizing, see Table #2 below: Key dimensions of 8 SMN Mixing elements. Complete SMN Mixing Nozzle. Table #2: Key Sizing and Dimensional Parameters for SMN Mixing Elements showed in Figures #10. For other O.D. and for larger sizes, please contact us. Dimensions are approximate. Recommended tolerances are dependent on installation method and operating conditions.