Calculating the Differential Head of a Pump

Read the manufacturer's spe'c or measure it (simple pressure gauge on the output).

I don't really get 'calculate it'... calculate it from what?

Del

PS.. If it really is differential, move pressure gauge to the input.... subtract one from t'other....

TOTAL DIFFERENTIAL HEAD (THD)=System Head = total discharge head - total suction head, i.e.

H = h_d - h_s

h_d = h_sd + h_pd + h_fd h_s = h_ss + h_ps = h_fs where: h_d = total discharge head h_s = total suction head h_sd = discharge static head h_ss = suction static head h_pd = discharge surface pressure h_ps = suction surface pressure h_fd = discharge friction head h_fs = suction friction head

Do you want to MEASURE the Diff. Pressure developing?

Then you take Gauge Pressure at Outlet P2

And maybe < Negative>= Pressure below atmospheic> at Suction. P1

p2-p1 Is Pump's Diff . Pressure at that place.

Subtract outlet pressure and inlet measured pressures. Convert then the differential pressure into head

e.g.

Differential Head (m) =(p(bar)*10.1)/Sp. gravity

you will get differential head across the pump!

One uses arithmetic: subtract the inlet pressure from the outlet pressure.

Simplesξ.