UFC 3-240-13FN
25 May 2005
controlled by an external device or by tying into a feedwater or blowdown circuit. This
type of setup can also be found on small cooling towers (see Figures 7-2 and 7-3).
Figure 7-2. Manual Chemical Feed System
Figure 7-3. Automatic Chemical Feed System
7-2.3
Automatic Neat Chemical Feed. The term "neat" refers to a concentrated
chemical as received, with no dilution or mixing. An automatic chemical feed system
must deliver the chemical proportionally (see Figure 7-4). Chemical pumps must be
sized appropriately, and the system must have control equipment, which can consist of
sensors, automatic valves, water meters, and timers. Once a system is properly
connected to the chemical containers and adjusted, the only contact between the
operator and the chemical containers results from maintenance of the chemical pumps,
valves, and transfer lines. The most desirable chemical feed method is to feed product
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