A constant-flow, high-pressure watermaker uses one pump to push a steady stream of seawater through its membranes, and a valve on the outlet to hold the pressure that makes reverse osmosis work. Fresh water passes through the membrane; the rest leaves as brine.
That short pressure path is where the three practical benefits come from: little maintenance, membranes that stay clean without chemicals, and a build that fits around the boat. It is the design Dessalator has built its watermakers on for more than 45 years.
Minimal maintenance
The parts under pressure are the pump, the membranes, and the regulating valve. There is no second pressure stage, so there is less to seal, adjust, or wear.
Day to day, upkeep is a fresh-water rinse after running, a pre-filter change when it clogs, and a look over the hoses and fittings.
Clean membranes, no chemicals
Only a small share of the seawater pushed through the system becomes fresh water. The rest sweeps along the membrane surface and carries salt and fine particles out with the brine before they can settle.
Because the pump delivers a fixed flow, that sweep holds steady whatever the pressure or the state of the membrane. The membrane cleans itself as it works, so routine care is a fresh-water rinse to displace the seawater left inside; Dessalator, for example, only recommends sterilising before a lay-up of more than four months.
Modular construction, easier installation
A modular system such as a Dessalator arrives as separate units: pump and motor, membrane tubes, pre-filters, and control panel, joined by hoses. Each one has a small footprint of its own instead of one large box that needs one large space.
The membrane tubes can lie along a locker or under a berth, the pump goes where it can be bolted down and reached, and the panel goes where you can see it. The pre-filter, the part you will touch most often, can sit where it is easy to open.
The short version
A steady flow keeps the membranes clean, a short pressure path keeps servicing simple, and a modular build lets the system fit the boat rather than the other way round. Those three follow from the same design decision: one pump, one valve, and seawater kept moving.
Related reading: How much electrical energy does it take to make 100L of fresh water?
Advance Yacht Systems supplies the Dessalator range and can help match a system to your boat. Get in touch to talk it through.