On Sunday, May 28, 2017 at 4:04:30 PM UTC-4, wrote:
On Sunday, May 28, 2017 at 11:35:39 AM UTC-4, wrote:



You are over thinking the situation. A multistage pump has a bunch of identical sections all turning at the same speed. Each stage increases the pressure. So you might have a 6 stage pump with each stage increasing the pressure by 10 psi. Which makes for a fairly efficient pump which will supply water at 60 psi. Google it.


From Wik

Multistage centrifugal pumps
Multistage centrifugal pump[5]

A centrifugal pump containing two or more impellers is called a multistage centrifugal pump. The impellers may be mounted on the same shaft or on different shafts. At each stage, the fluid is directed to the center before making its way to the discharge on the outer diameter.

For higher pressures at the outlet, impellers can be connected in series. For higher flow output, impellers can be connected parallel.

A common application of the multistage centrifugal pump is the boiler feedwater pump. For example, a 350 MW unit would require two feedpumps in parallel. Each feedpump is a multistage centrifugal pump producing 150 l/s at 21 MPa.

All energy transferred to the fluid is derived from the mechanical energy driving the impeller. This can be measured at isentropic compression, resulting in a slight temperature increase (in addition to the pressure increase)..



Dan