established by the manufacturer or by local command. Inspect the speed reducer each
week to make sure that the oil is at the proper level, is free of water and grit, and is of a
suitable viscosity. If a reducer runs hot during its operation, the oil level may be too
high or too low. When the reducer is out of service for extended periods, make sure
that it is filled completely to prevent seals from drying out. Replace oil when
Overload Alarm. If the equipment has an overload alarm, check it for
operation. If the alarm sounds at any time, shut off the equipment, locate the source of
trouble, and rectify the situation. Disabling the alarm switch is not recommended. It is
important that the alarm provide continuous operation under overload (high-torque)
conditions. If the overload is caused by a sludge buildup leading to cut-out of the
starter switch or pin shearing, drain the tank and flush out the sludge.
Upflow Clarifiers and Solids Contact Units. These are all proprietary
items; maintain them according to the manufacturer's instructions. Devices that use
rotating parts have motors and gears that require maintenance.
Operator's Inspection. Check for leaks in valves and piping each
month. Make sure that sludge valves function properly. Also check time clock and
other accessories that control sludge valve operation.
Cleaning Maintenance. Drain unit, clean, and inspect wearing
parts twice a year. Remove encrustation where it may interfere with operating parts;
follow the manufacturer's instructions in this operation. Check chemical feed lines to
make sure that they are not clogged and are in good condition.
Gravity Filters. This paragraph deals with maintenance of conventional
or rapid filters, formerly known as "rapid sand filters." Media commonly used in rapid
filters include graded sand, crushed anthracite, GAC, and garnet or ilmenite. Media
types may be used alone, as in traditional sand filters and deep-bed monomedia filters,
or in combination, as in dual and tri- or mixed-media filters. The following maintenance
procedures supplement (but do not substitute for) requirements established by the
equipment manufacturers. A quick reference guide to maintenance of gravity filters
appears in Table 36.