What is Reverse Osmosis?

The osmotic process involves the natural movement of a solution through a semi-permeable
membrane without applying external pressure. The membrane allows the passage of solvent but not
of solute. In Reverse Osmosis, high pressure is used to push the solution through a membrane
which traps the solute on one side making pure solvent obtainable from the other side.

How does it work?

In the case of marine water purification, sea water is driven under high pressure through a special
membrane. The resulting “Product Water” is potable water with over 99% of the Total Dissolved
Solids (TDS) removed. The Product Water is directed from the watermaker to an appropriate location
such as a fresh water holding tank. The permeate that does not successfully pass through the
membrane is sometimes referred to as the “brine discharge”, and is also directed to an appropriate
place. For example, on vessels, the brine discharge is diverted overboard.

A marine desalinization system begins with a through-hull fitting, or skin fitting, where raw sea water
is initially drawn into the system. The raw sea water is then filtered through a sea strainer to approx-
imately 50 microns, and further filtered to 5 microns by being pumped through a Pre-Filter using a
low pressure pump running at approximately 30-35 psi. Now, the Reverse Osmosis process begins.
The filtered sea water is then pumped under high pressure (at approximately 800-850 psi depending
upon the temperature and salinity of the sea water), through the reverse osmosis membranes. The
water that successfully passes through the membranes (product water) is then routed to a salinity
probe which confirms the quality of the product water. If the product water is acceptable, this purified
water is transported to a fresh water holding tank. Unacceptable product water which does not pass
the salinity test is discarded and diverted with the brine discharge.

FCI's exclusive UROC technology allows you to monitor water production and control your water
purification system from a computer and remote locations. FCI Watermakers are among the most
effective desalinization systems which provide automatic and customizable fresh water flushing. This
feature is integral to every marine water purification system because it deters growth of biological
contaminants when the system is not in use.

Additional marine watermaker accessories include a UV sterilizer, which kills over 99% of all
micro-organisms in the water, and a charcoal filter, which neutralizes water odors and taste.