MIL-HDBK-1005/9A
4.6.3
Controls. Controller devices are needed to regulate
the functions of equipment throughout the process. Controls may
be classified by the degree of automation.
4.6.3.1
Manual. Use this type of control where the operator
will start, stop, or adjust rates of operations based on
instrument observations, laboratory tests, or indicated
conditions.
4.6.3.2
Automatic. Use this type to automatically start,
stop, or regulate rates of operations in response to changes in
a measured variable or other input. All equipment must also
have manual control to override automatic control regardless of
the degree of automation provided.
4.6.3.3
Design Considerations. Many controls combine manual
and automatic operations. The operator may initiate an
automatic-timed cycle backwash system, or adjust set points of a
proportional controller based on instrument observation.
Controls that seldom require adjustment (rate of flow to
filters, for example) should be manual. Controls requiring
frequent adjustment (starting sump pumps, proportional chemical
feeding) should be automatic. Whether the automation is on/off-
timed cycle, or proportional, must be based on analysis of plant
requirements.
4.7
Chemical Handling and Feeding
4.7.1
Introduction. See Table 19 for function of chemicals
used for cyanide, oil, and metal removal. Sections 2 and 3
recommend specific chemicals for wastewater applications
encountered in Navy facilities. See Table 20 for the usual
chemical strengths and other data on chemicals.
4.7.2
Chemical Handling and Feeding
4.7.2.1
Handling. See Table 20 for handling precautions.
Provide the following:
a)
Roofed unloading platforms.
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