Rain water storage equipment for supplying water for domestic purposes unless water level in storage cistern falls below a minimum level

摘要

Rain water in a cistern (Z) is fed to a domestic water supply (HWV) via a pump (P) through a non-return valve (RV). Below a minimum (NM) level in the cistern a small storage tank (SB) provides the supply through a valve (15) opened by a control unit (ST) The tank is supplied from the drinking water system through float switches (17,18) with the intake pipe above the maximum level (N) to avoid back feed into the drinking water system