Jump to content

  • Log in with Facebook Log In with Google      Sign In   
  • Create Account


Chemical and Process Engineering Resources

Centrifugal Pumps: Basic Concepts of Operation, Maintenance, and Troubleshooting

Nov 08 2010 11:30 AM | Mukesh Sahdev in Fluid Flow ***** Share this topic:
| More

The operating manual of any centrifugal pump often starts with a general statement, "Your centrifugal pump will give you completely trouble free and satisfactory service only on the condition that it is installed and operated with due care and is properly maintained."

Despite all the care in operation and maintenance, engineers often face the statement "the pump has failed i.e. it can no longer be kept in service". Inability to deliver the desired flow and head is just one of the most common conditions for taking a pump out of service.

There are other many conditions in which a pump, despite suffering no loss in flow or head, is considered to have failed and has to be pulled out of service as soon as possible. These include seal related problems (leakages, loss of flushing, cooling, quenching systems, etc), pump and motor bearings related problems (loss of lubrication, cooling, contamination of oil, abnormal noise, etc), leakages from pump casing, very high noise and vibration levels, or driver (motor or turbine) related problems.

The list of pump failure conditions mentioned above is neither exhaustive nor are the conditions mutually exclusive. Often the root causes of failure are the same but the symptoms are different. A little care when first symptoms of a problem appear can save the pumps from permanent failures. Thus the most important task in such situations is to find out whether the pump has failed mechanically or if there is some process deficiency, or both. Many times when the pumps are sent to the workshop, the maintenance people do not find anything wrong on disassembling it. Thus the decision to pull a pump out of service for maintenance / repair should be made after a detailed analysis of the symptoms and root causes of the pump failure. Also, in case of any mechanical failure or physical damage of pump internals, the operating engineer should be able to relate the failure to the process unit's operating problems.

Any operating engineer, who typically has a chemical engineering background and who desires to protect his pumps from frequent failures must develop not only a good understanding of the process but also thorough knowledge of the mechanics of the pump. Effective troubleshooting requires an ability to observe changes in performance over time, and in the event of a failure, the capacity to thoroughly investigate the cause of the failure and take measures to prevent the problem from re-occurring.

The fact of the matter is that there are three types of problems mostly encountered with centrifugal pumps:

  • design errors
  • poor operation
  • poor maintenance practices

The present article is being presented in three parts, covering all aspects of operation, maintenance, and troubleshooting of centrifugal pumps. The article has been written keeping in mind the level and interests of students and the beginners in operation. Any comments or queries are most welcome.





Fluid Flow Articles



15 Comments

Photo
Syed Muhammad Fawad Abdi
Jan 11 2012 02:24 PM
Nice article it is . .
thank you for sharing this informations
really good!
useful topic
Thanks for informative post
Very good piece of information. Thanks for providing us this information
realy very nice..
really good piece of information, Thanks for posting it..
Photo
shaikh abdul aziz
Dec 16 2012 05:21 AM
really very informative
Photo
MURUGANANDHAM.P
Jan 21 2013 09:58 PM

Very help to all of them.

I think in Equation 9, fiction loss should be subtracted rather than being added, to get NPSHa.  

could anyone tell me about 'hunting in pumps'??

Photo
Mudssar Sohail
Aug 05 2013 01:56 AM

very very nice article , its clear all concept about Pumps

Photo
angelina_singgar
Dec 09 2013 01:15 AM

good to understand.

Nice Article. Very helpful.