CDL(F) Pumps for Reverse Osmosis and Filtration Feed

Membrane systems need a steady flow at a set pressure, with clean water and stainless wetted parts. That is exactly where a vertical multistage pump fits. Ultrafiltration, reverse osmosis, distillation units, separators and swimming pool filtration are all on the CDL(F) list of uses.

Sizing from the membrane

1. Take the feed flow from the system design, not the permeate flow.
2. Ask the membrane supplier for the pressure needed at the pump outlet. 1 MPa is roughly 100 m of head.
3. Add the losses through the pre-filters and pipework.

An example

A unit needs 8 m³/h of feed at about 1.2 MPa at the pump outlet, roughly 120 m. The CDL(F) 8-130 gives 121 m at 8 m³/h with a 5.5 kW motor.

Good practice

• Protect the pump from running dry when the feed tank empties; an optional protector covers dry running
• Start against a partly open valve so the membranes are not shocked
• Choose the hot water version only if the liquid needs it

More sizes in the CDL(F) selection table.