SUBJECT: READ: ASSIGNMENT: COMMENTS: LESSON 23 Pump Scaling Laws: Pump Specific Speed and the Affinity Laws Sections 14.2, 14.4 Homework Problem: Using affinity laws, develop a pump curve and BHP curve for a 12" AB pump for a 6" impeller. Use a 1750 rpm curve as the "known" characteristics and develop a theoretical curve using affinity laws for 3500 rpm based upon flow rates 0, 20, 40, 60, 80 and 90 gpm at 1750 rpm. Plot the theoretical (affinity-based) and published flow vs. head and flow vs. horsepower curves for 3500 rpm. The dimensionless parameter of pump specific speed, Nsp, can be used in the selection and design of centrifugal pumps. When operating at the pump's best efficiency point, the pump specific speed helps define the type of pump that should be used in a given application: i.e., centrifugal, mixed flow, or axial. The specific speed is related to the maximum possible efficiency of a given type of pump. Since many centrifugal pumps can be equipped with variable speed drives and with different sized impellers, pump manufacturers typically o for a single pump Alternatively the