The following is the advancement of what I discussed in the link https://www.physicsforums.com/showthread.php?p=4274966#post4274966 Problem Statement To calculate Pump Discharge Pressure, Calculate the wattage for the pump Data : Water @ 85 Degree C Flow in for 24” pipe : 3010 m^3/hr Flow in 8” pipe : 405 m^3/hr Total length of pipe = 50ft Nozzle Dia : 1" Nozzle pressure : 100 psi Nozzle Gallons per minute = 119 Number of Nozzles = 110 (placed equidistant along the length of the pipe) Kinematic & Dynamic Viscosity of water can be found on : http://www.engineeringtoolbox.com/water-dynamic-kinematic-viscosity-d_596.html Is my approach (mentioned below) correct ? Pump Discharge Pressure = Pressure Loss owing to flow thru Horizontal Pipe + Nozzle Pressure* Number of Nozzles Then, Find Reynolds Number Determine if its turbulent or laminar flow? Find the relative roughness of the pipe Find the friction factor, either from Moody’s chart or Colebrook equation Then calculate pressure loss = (fρLV^2)/(D*2) in Pascal Now calculating Nozzle Pressure , Already given that per nozzle 100 psi. So total pressure loss owing to nozzles; is 100*110 and convert to Pascal units. Then add ; pressure loss (calculated above) with the Pressure loss owing to those 110 Numbers of nozzles... and, use the above addition and multiply with the flow rate to attain the wattage ? Is this approach Correct ? Am I missing something ?