... rate. Grundfos, Tonakflo or others. 316 stainless steel.Multi-Media FilterMulti-media filtration system is used to filter sand ... equivalen. On larger units ZYI uniquely design pumping system, including multi-stage centrifugal pump, energy recovery turbine, and variable frequency drive, ... Pressure Gauges: on the inlet and outlet of every filtration stage, and before and after each RO membrane vessel.11. ...