1 reply to this topic

[asade abiodun]

Hi,

What is the effect of having a very high Total Differential Head. The reason for my question is:

NPSHA for the pump is 18 m
TDH is 18m

Is there any relationship with the two?

thanks for your responces.

[Zauberberg]

NPSHA is immanent to your specific system (service fluid conditions, flowrate, elevation profile etc.) while TDH is characteristic of the pump and it is a function of actual flowrate. There isn't any relatioship between these two parameters (NPSHA/TDH), as far as I know about pumps.

There is dependancy between pump flowrate and NPSHR (due to higher friction losses when liquid accelerates at the eye of impeler at higher flowrates), and it is usually given as chart-type data NPSHR vs Q.

There are many free internet resources for centrifugal pump design and operation, look at:

http://www.cheresour...galpumps1.shtml
http://www.mcnallyin...aper_index.html

Regards