which conserves water but is still highly effective in emergency situations

Corrosion Resistant Schedule 80 PVC Construction with All Stainless Steel Valve Fittings

Bradley S43-012 "Service" Ft Lvr Treadle Assy Replacement Part

0 gallon capacity

and countertop models

Hayward Threaded Pressure Reducing Pressure Reducing Control Valve, 2 in Pipe Size - PBV3200TPE1 Dual Roll Toilet Paper Dispensers which conserves water but isIdeal for chemical feed systems, this HAYWARD pressure reducing control valve can apply back pressure to a metering pump to help prevent siphoning and eliminate variable dosage rates due to a fluctuating downstream pressure. When the valves preset pressure is exceeded (model has an adjustment screw that you can adjust in the field), the diaphragm moves up and chemical flows through the valve to the injection point.