axial thrust

[robtgarn]

The analysis for predicting axial thrust in a single stage open impeller pump is straight forward. Is the same formula used when putting these pumps in series? Specifically, the last pump in my series will see 400 psi inlet pressure. Is it as simple as plugging in my 400 psi for P inlet? That would mean my axial thrust will now be towards the motor rather than away from it as in a single pump?

 

[TenPenny]

I think the key thing to consider is how your system will perform - that 400 psi suction pressure will only be a constant if the flow is constant, so consider all possibilities.

 

[1gibson]

If you have the thrust that the pump generates with 0 suction pressure, and all the pumps are identical, then yes it should be easy (for checking a single set of conditions.)

That thrust - (suction pressure x (seal sleeve area and shaft cross section area at the seal))

Upthrust is bad, and you will want to check shaft stretch and adjust lift settings for open vane pump.

Make sure fabs are good for the higher pressure, mechanical seals designed to operate at the increased seal chamber pressure, etc.

 

[Artisi]

You will need to supply more info. on the pump configuration etc to get a meaningful answer.
IE, pump type / style -- full / partial or no back blades on the impeller, balance holes etc etc.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[bimr]

Pumps must also be selected with sufficient thrust capacity to counteract forces set up under the maximum suction pressure established as a limit for that particular pump.

http://www.kelairpumps.com.au/images/stories/PDF/PumpClinic/PumpClinic12.pdf

http://www.pump-zone.com/topics/pumps/centrifugal-pumps/centrifugal-pump-axial-thrust