Figure 1-15. Water purification unit, van type body mounted, 3,000-gph.
(e) Water purification unit, base mounted, 3,000-gph. This item is
essentially the same as the van type body mounted unit except that it is mounted as a
permanent or semi permanent installation. It also has an oiI fired water heater for use
under arctic conditions.
(f) Water purification unit, 10,000-gph. The 10,000-gph unit is the
largest standard water purification set utiIizing the erdlator. It differs from the smaller
sets in that it employs two rapid sand fiIters rather than diatomite fiIters. This unit, Iike
the 3,000-gph base mounted set, is used in permanent or semi permanent installations
(rear area support areas which is manned for an extended time).
b. Engineer Water Purification Set No.4. This unit is no longer service in
some reserve component units and in allied forces receiving US MiIitary assistance.
The Engineer Set No.4 has a 3,OOO-gph capacity. It uses conventional batch
pretreatment with alum and soda ash and separate batch disinfection. It is equipped
with the diatomite fiIter.
c. Reverse Osmosis Water Purification Unit. Reverse osmosis water
purification units (ROWPU) are used to purify fresh, brackish, or salt water. They are
replacing erdlators. Reverse osmosis is the opposite of osmosis. Osmosis is nature's
biological way or process of passing more a dilute or clearer solution through semi-
permeable or semi-porous membrane into a more concentrated solution (from a pure to