This document discusses minimum flow systems for pumps. It describes three types of pump recycle systems used to protect pumps from operating at low flows: continuous recycle systems using an orifice, control loop systems using a control valve, and automatic recirculation systems. It provides guidance on applying each type, including considerations for sizing recycle flows, locating flow meters and control valves, dealing with pressure drops, and routing recycle lines. The document asks how pump capacity should be stated if a pump has a continuous 30 gpm recycle flow added to its 100 gpm normal flow.