be considered in the plans of the enemy.
Distillation equipment cannot produce water
quickly enough to be used for fire protection.
Do not permit your treated water to be used for
this purpose except in extreme emergencies.
Raw water should be used whenever possible.
The use of reverse osmosis water purification
equipment by the military has produced potable
water from the sources available in a combat field
environment. The reverse osmosis water
purification unit (ROWPU) is capable of treating
freshwater, brackish water, and seawater.
Additionally, the unit is capable of treating water
contaminated with chemical, biological, and
radiological warfare agents. When using the
unit to treat water contaminated by CBR agents,
you must use the equipment in conjunction with
auxiliary ion exchange and carbon adsorption
The ROWPU used by the NCF is capable of
producing 600 gph of product water from
freshwater sources and 400 gph of product water
from seawater at 70°F. The rate of water
production in the ROWPU depends upon the
operating pressure, normally 350 to 550 psig for
freshwater and 750 to 950 psig for seawater.
Temperature affects the rate of flow. Cold water
decreases the flow, while warm water increases
N O T E : M a x i m u m o p e r a t i n g w a t er
temperature of the ROWPU feedwater is 120°F.
Water temperatures above this figure may damage
the membranes within the reverse osmosis
Reverse osmosis (RO) is a purification
process in which filtered water is pumped
against a semipermeable membrane under
great pressure. The membrane allows
product water to pass through while rejecting
impurities, both dissolved and suspended.
You must use an extremely high pressure for
a usefull volume of water to pass through a
unit membrane. The reverse osmosis process
is shown in figure 9-13(A). Reverse osmosis
may appear to be nothing more than a
filtering process, but there are distinct
differences. In filtration, the entire liquid
stream flows through the porous filter
medium and no chemical changes take place
between the feed and the filtrate. In RO, the
feed flows parallel to the semipermeable
membrane with a fraction of it passing
through a given membrane area; dissolved
ionic and organic substances are rejected by
the membrane and, in this case, drained off as
Figure 9-13(A).Reverse osmosis process.