StairFlight SF-1 Passive, Head-Assisted Hydraulic Ram System for Non-Potable Toilet Supply in Multi-Storey Buildings Design Note (Kaizen / Incremental Infrastructure)

Abstract This document describes a modular, passively actuated hydraulic ram system (“StairFlight SF-1”) intended to lift clean, non-potable water to elevated header tanks for toilet flushing in multi-storey residential buildings. The system is driven primarily by gravitational head pressure and employs discrete, self-locking hydraulic states rather than continuous control. Optional mechanical coupling to stair footfall may be used solely to initiate or stabilise cycling. The design prioritises robustness, inspectability, and staged validation, and is presented as an incremental infrastructure component suitable for retrofit or integration into new builds.