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 .

Accessed: 13/06/2014 00:07

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact support@jstor.org.

.

Water Environment Federation is collaborating with JSTOR to digitize, preserve and extend access to Sewageand Industrial Wastes.

http://www.jstor.org

This content downloaded from 188.72.126.181 on Fri, 13 Jun 2014 00:07:09 AMAll use subject to JSTOR Terms and Conditions

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.

This content downloaded from 188.72.126.181 on Fri, 13 Jun 2014 00:07:09 AMAll use subject to JSTOR Terms and Conditions

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

This content downloaded from 188.72.126.181 on Fri, 13 Jun 2014 00:07:09 AMAll use subject to JSTOR Terms and Conditions