The modular design consists of individual thin film composite membranes cushioned between hydraulic cover disks, stacked, and assembled about a center tension rod and effectively sealed
between metal end flanges.

Disc Tube Module Operation

Seawater flows down passages between the disc stack and the pressure vessel and enters the flow chamber from beneath the bottom disk. The flow is directed up and over each membrane cushion allowing pure water to pass through the semi-permeable membrane and be collected by the permeate collector. Feedwater contamination is prevented by 'O' ring seals fitted to the hydraulic disks. As the pure water is removed the strongly concentrated feed is taken away to discharge. The open channel created by the membrane cushion enables fully turbulent feedwater and permeate flow. It can also operate on sea water with a silt density index (SDI) as high as 20 without risk of fouling the RO membranes.