Steps to determine the hydraulic horsepower (whp) for pump problems:
1) Determine (hA) by rearranging the Bernoulli equation.
2) Apply (hA) into the equation found in the table along with the flow rate (gal/min or ft3/sec), and the specific gravity (SG, typically given), OR use the mass flow rate equation (last column in the table).
hA = (p/γ)2 - (p/γ)1 + (V2/2g)2 - (V2/2g)1 + (Z)2 - (Z)1 + hƒ
hA (Qgpm)(SG) / 3956 or hA (Qcfs) (SG) / 8.814
For the mass flow rate = (8.34 lb/gal for water)(flow in gal/sec)(SG) = lb/sec
hA (mass flow)/550