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Pump Spare PartsSource: Sewage and Industrial Wastes, Vol. 28, No. 11 (Nov., 1956), pp. 1429-1430Published by: Water Environment FederationStable URL: http://www.jstor.org/stable/25033214 .
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Vol. 28, No. 11 PUMP PARTS 1429
Chlorination and Odor Control
Odors were held under control
through the use of an odor-masking compound in the exhaust ventilating system at the headworks, and the pre chlorination of the influent. (All units at the plant are housed.)
The sulfide content of the sewage increases appreciably during warm
weather and makes adequate odor con
trol imperative. Usual practice is to chlorinate the entire effluent, including that which is recirculated. Chlorina tion of the final effluent on the down stream side of the flow meter is also
practiced to maintain a .1 to .2 p.p.m. residual. When the sulfide content increases substantially it is necessary to chlorinate the influent directly. A total of 44,767 lb. of chlorine was
used during the year. The drip system of applying the
masking agent was changed in favor
of an atomizer constructed with a small air compressor. Operation was great
ly improved.
Miscellaneous
Miscellaneous maintenance included
cleaning and painting the primary oxi
dator, replacing corroded gas collect
ing piping to the primary digester, and various overhaul and routine mainte nance tasks.
Although labor costs increased due to automatic salary increases, the total
operating cost of the plant decreased. Chemical costs were lower because of a one-third reduction in chlorine used. The saving in fuel gas for digester heating amounted to $400.
Construction of the oxidation pond was considered as a capital improve ment expense.
Operating data for 1954 are sum marized in Table II.
PUMP SPARE PARTS *
A pump, like any other piece of
machinery, is subject to wear and will need to have some parts replaced after a period of operation. The frequency of repair, as well as the number of
parts to be replaced, is determined
largely by the severity of the service. Wear is affected by the properties of
the liquid such as temperature, cor rosiveness and abrasiveness, as well as
pump fit, suction conditions and the
adequacy of the installation. Obvi
ously a pump used for only a few minutes a day on clear water will be
subject to less wear than a pump op erated 24 hr. a day on hot, caustic
slurry. However, even the cold water
pump eventually will require some re
pairs.
Some parts should be on hand at all
times, since they must be replaced as soon as they become excessively worn or fail. Parts that are in this class
include bearings, bearing shells, shafts and mechanical seals. Other parts
must be replaced when worn, but it is
usually possible to use the pump on a limited basis until new parts can be obtained. Such parts normally include
sleeves, impellers, casing wearing rings, sideplates, glands and possibly casings on certain liquids. Limited
operation may be much better than no
operation, but it may also result in loss of valuable production and exces sive maintenance. As an example, the
casing wearing ring may become worn, increasing the clearance and the in ternal leakage or recirculation back to the suction side of the impeller. This reduces the capacity pumped until the
pump may be unable to produce a sufficient flow to maintain rated pro duction.
Obviously, when pump parts be come badly worn they should be re
placed to restore the pump to first class condition. With a well organized sys
* Condensed from Gould News, July-Aug.,
1956.
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1430 SEWAGE AND INDUSTRIAL WASTES November, 1956
tern of preventive maintenance, it is
possible to detect and anticipate future
parts requirements. It is necessary that the specific parts which should be on hand at all times, be determined for each installation. Lists of recom
mended spare parts for pumps under normal conditions of service are in
cluded in most instruction books. These lists serve as a guide and must
be tempered by the specific conditions under which each pump operates. These conditions include the severity of service, and the cost if the pump service is interrupted while the re
placement is made.
The availability of spare parts should also be considered carefully for each pump. A complete set of spare
rotating parts should be kept on hand if the pump is essential to plant opera tion.
Pump spare parts can be considered as a free insurance policy. The pre
mium is paid when the parts are
bought but a dividend is obtained in
the form of minimum delay in return
of a pump to service. It is suggested that the spare parts inventory be re
examined and the proper parts ob
tained before a pump failure occurs.
TIPS AND QUIPS
Monthly Instructional Letters
A series of monthly letters to water
and sewage plant operators was in
augurated in Ohio in March 1956 un
der the auspices of the Ohio short
school sponsors. Associate Professor
Kenneth W. Cosens of Ohio State Uni
versity is the letter writer.
Purpose of the letters is to help the
operators review the mathematics and
chemistry of plant operation. The
present general plan is to devote ap
proximately six months to mathemati
cal principles and computations, and
then follow this with six months on
chemical principles and computations of importance to water and sewage
plant personnel. Each letter covers
a different subject by presenting the
basic principles and necessary defini
tions. These are supplemented with
example problems, followed by a group of problems to be worked. Answers
to the problems are included in the
next letter.
The letters are financed at present
by the sponsors. Response has been
most gratifying, and apparently the
letters serve a real need among plant
operators.
Further information can be ob
tained from Professor Cosens, Depart
ment of Civil Engineering, Ohio State
University, Columbus 10, Ohio. Or
better still, organize monthly letters to operators in your own state through the facilities of your Sewage and In
dustrial Wastes Association, health de
partment or operators association.
Muralization
The Coral Gables, Fla., sewage treat ment plant is unusually attractive. Colorful murals and abstract designs have been painted on the large ex
panses of exposed concrete such as di
gestion tanks. These designs are vis ible from the main highway which
passes near the treatment plant, and have evoked considerable interest in
this facility which provides the citi zens of Coral Gables with modern sew
age service.
Acid Wastes Trucked Away
Stream pollution has long been of real concern in the highly indus trialized valleys near Pittsburgh. Some years ago the steel companies were faced with finding a way to dis
pose of increasing volumes of spent pickling acids without violating the law. Rather than invest in waste
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