operating periods and lubricated. Devices subject to
wide seasonal temperature changes must have
seasonal changes in lubricant grades, especially where
summer grade oils thicken below freezing and reduce
the flow capability. Daily or weekly lubrication of
operating units is a part of operator inspection. The
choice of lubricant and its frequency of application are
established by the manufacturer or by local command.
Mixing basins, whether baffled or mechanically
stirred (rapid or flash), require attention and cleaning
semiannually. The maintenance requirements are as
1. After draining, wash down the walls with a hose
and flush the sediment to the drain. Repair spalled spots
on walls or bottom as necessary.
Other devices found in the equipment require
attention on a regular basis. Some examples of these
devices and required care are as follows:
2. Check the valves or sluice gates for corrosion
and ease of operation; clean and lubricate; paint valves
1. The speed reducer should be inspected weekly
to ensure that the oil is at the proper level, is free of
water and grit, and has the right body. When a reducer
runs hot during its operation, the oil level may be too
high or too low. (Where the reducer is out of service for
a long time, make certain it is filled above the level of
the seals to prevent the seals from drying out. Be sure it
is tagged to reflect this condition. The reducer must be
drained to proper level before being placed back in
service.) Replace oil whenever necessary.
The following maintenance procedures apply to
Monthly, during operation, check paddle
rotation to assure that all flocculators are operating.
Lower a light pole (bamboo fishing rod) into the water
until the paddles strike the pole, revealing paddle
operation. Broken shafts or chains may cause the
paddles to become inoperative.
2. The drive head should be lubricated daily, but
not too much.
Semiannually, drain and clean the basin, walls,
and floor; inspect the flocculator mechanism, drive,
bearings, gears, and other mechanical parts; clean and
lubricate. Especially check underwater bearings for silt
penetration. Replace scored bearings. Paint mechanism
parts where necessary.
3. The worm gear oil level should be checked at
least weekly, and the water drained from the housing
4. The turntable bearings should be lubricated
monthly and the oil changed twice yearly.
All types of settling basins require the same basic
maintenance, such as lubricating, cleaning, flushing,
and painting. Basins, which have mechanical devices,
should be maintained under the manufacturers
5. Lubrication procedures for chains depend on the
design of the chain and chain guard. Inspect monthly
and add oil as necessary; drain off the accumulated oil
as necessary; and change the oil twice yearly.
6. Ball bearings and thrust bearings are lubricated
Revolving-Sludge Collector Basins
annually. They should be inspected monthly for wear
and proper lubrication.
Specific maintenance procedures for revolving-
sludge collector basins should agree with the
manufacturers instructions. The procedures described
here are the minimum.
7. Center bearings, shaft bearings, bushings, and
so on, are lubricated under the manufacturers
Regular lubrication is required where the basin is
in continuous operation. Intermittent operation affects
the lubrication schedule, making it possible to increase
the interval between lubrication periods. When
operating periods are intermittent and infrequent, the
mechanism should be operated briefly between
Tank equipment requires annual inspection. The
steps for this inspection are as follow:
1. Check bolts and tighten nuts to maintain
original alignments and adjustments.