Page 179 - CW E-Magazine (8-10-2024)

Special Report

Corrosion in pumps with case examples from water

service and oil well operation

INTRODUCTION The causes of premature or sudden Dr. S.K. ChaKravorty
orrosion is the reaction of a pump failures Consultant (Plant Engineering)
metallic material with its envi- Many issues have been identified Email: chakravorty4410@gmail.com
Cronment. In most cases the that can lead to pump failure. However,
reaction concerned is electrochemical it is often a series of issues or their tion, insufficient lubrication or
and can only take place in the presence combination that eventually leads to foreign objects blocking the cooling
of ion-conducting solutions (electro- pump failure. Following are major fins.
lytes). This is called a redox reaction, reasons for pump failure:
since it is divided into two parallel Vibration: Excessive vibration can
semi-reactions: anodic oxidation (dis- Lack of proper maintenance: Pumps damage the internal parts and lead
solution of the metal) and cathodic in need regular maintenance like any to pump failure. These vibrations
the electrolyte (involving reduction of other machinery. If they are not ap- are caused generally due to align-
ions)(1, 2). propriately maintained, it can lead ment issues, inherent installation
to pump failure. issues or even overuse of pumps.
Corrosion is one of the main reasons
for pump failure. When buying pump- Foreign objects: Foreign objects Electrical issues: Electrical problems

ing equipment, material selection and such as dirt, debris, rocks or gravel such as voltage surges or power
coating technology must be considered. can get into the pump and cause outages can damage a pump and
Water pumps in water works and pro- damage or blockages. This can lead cause it to fail. Many protective
cess industry and electrical submersible to pump failure or even damage the devices can safeguard the pumps
pumps used in oil & gas industry are piping system. from this, but sudden surges can
among the most critical pumping ope- still cause pump failure.
rations. These pumps must have a sturdy Worn out parts: The moving parts

design and made of robust materials. in a pump will wear out with time Cavitation: Cavitation is a condi-

The knowledge of the pump engineer in and need to be replaced. If they are tion where air pockets are formed in
the selection of components is crucial not replaced as per the pump manu- the liquid being pumped. This can
in deciding the reliability and durability facturer’s schedule, it leads to pump damage the pump and eventually
of the pump. However, at times, even failure. lead to failure.
after taking all precautionary measures,
unexpected pump failures can still Incorrect installation: All pumps Corrosion: Corrosion in pumps

occur in operation. need to be installed as per the pump results from chemical reactions
manufacturer’s recommendations. between the pumped fluid and exposed
Industrial processes across the If a pump is not installed correctly, metal surfaces. It results in impaired
globe require pumps to operate reli- it can cause problems and lead to performance and increased main-
ably and efficiently. The latest pump pump failure. tenance costs. In extreme cases,
designs and coating technologies offer corrosion can cause the premature
significant improvements in the long- Poor quality: Using a poor-quality failure of equipment.
term performance of industrial pumps. pump can lead to various problems,
By minimizing the effects of corrosion, including pump failure. This is why Corrosion is caused by chemical
users can enhance productivity and you must always procure pumps reactions between the pumped fluids
reduce running costs. By gaining a from a reliable pump manufacturer. and exposed metal surfaces, as well as
better understanding of both the pump- external environmental factors. Corro-
ing process and the factors that induce Overheating: Overheating is one of sion can affect the wet surfaces of the

corrosion, users can make significant the most common causes of pump pump’s internal components, such as
improvements in their maintenance failure. It can be caused by several the impeller, suction side plate, and
strategies. factors such as incorrect installa- nozzle and can cause the pump to fail.

Chemical Weekly October 8, 2024 179

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