Significance of TDH (Total Differential Head)
Significance of TDH (Total Differential Head)
(OP)
Could somebody tell the usefullness of TDH.
I know TDH is Total discharge head minus total suction head (plus if it is suction lift).
My feeling is that if you calculate the TDH then you can determine the flow rate from the pump curve.
Am I right?
If not can somebody enlighten me.
I know TDH is Total discharge head minus total suction head (plus if it is suction lift).
My feeling is that if you calculate the TDH then you can determine the flow rate from the pump curve.
Am I right?
If not can somebody enlighten me.





RE: Significance of TDH (Total Differential Head)
This assumes the pump is properly installed and is in the same condition as when the curve was originally generated (if it's a certified curve or at least, same condition as the generic pump used to generate the curve).
RE: Significance of TDH (Total Differential Head)
RE: Significance of TDH (Total Differential Head)
RE: Significance of TDH (Total Differential Head)
The intersection of the pump curve (for the impeller size installed) and the system curve. The system curve must be calculated - you must count all fittings and line lengths and compute the system resistance K.
For the system curve, the TDH REQUIRED INCREASES with higher flowrates - while for the pump curve, the AVAILABLE TDH DECREASES with higher flowrates.
Again, this is where the pump would like to operate; but it will do so ONLY IF THE NPSH is adequate.
The more you learn, the less you are certain of.