Centrifugal Pump RPM question

Hi. I have another rookie question.

While performing SAT on a CIP system, I came across a discrepancy on the pump RPM between the equipment cut-sheet and the specification indicated on the actual pump nameplate. The discrepancy is just a bit off between the cut-sheet and the nameplate. For example, the cutsheet specifies 3500 RPM, however, the nameplate indicates 3520 RPM.

This actually is the case for the 2 other pumps in the systems as well. Is this normal? If so, could someone please provide some insight and clarification of why this happens?

Thank you in advance for all your inputs.


Hi Jake,
This is really good question.
I have no idea about this. Your point is very strong and valid.
I have asked some of my peers in Industry and I hope I should get answere on this soon.



The speed of the pump can vary depending on the frequency.
For example in Europe the frequency is 50 Hz, while in US it’s 60 Hz.



Hey Rookie,

What does the URS specify or is there no specification?

You can get the supplier to update their documentation and also pick up during DQ/IQ or the P&ID walkdown.

Just as long as you are not going to leverage any tests from the SAT its a minor infraction that can be handled through documentation.


Ok, I’m going to be a little nicer about this. gac was correct in that you should refer to the URS. provided the 20 RPM difference still meets the requirements in the URS or FRS, this can be handled as a minor source document discrepancy. In most cases the equipment should be ordered to exceed the requirements so that little things like this are not a big issue. Of course that is provided they did not write the requirements to the vendor cut sheets.