This chapter extends the fundamentals of feeder selection and integration by presenting a comprehensive analysis of feeder performance, loads, and design objectives for bulk solids handling. Emphasis is placed on the critical interaction between mass flow hoppers and belt or apron feeders, with particular attention to achieving uniform draw down along long slotted outlets. Analytical models are developed to describe velocity profiles, volumetric efficiency, and throughput variation along the feed zone, leading to criteria for optimum hopper geometry and divergence angles. The chapter further examines stress fields generated during initial filling and during flow, distinguishing between active and passive states and demonstrating their profound influence on feeder loads and drive power requirements. Design methods for predicting initial and flow loads, shear forces, skirt plate resistances, and non slip conditions are presented in a unified framework. Practical guidance for controlling feeder loads is provided, supported by illustrative case studies, thereby linking theoretical analysis with proven industrial practice.