MICROFICHE REFERENCE LIBFUUW - Cd3wd.com

(c) The static discharge head (HsD) is similarly the verticaldistance from the pump centerline or device inlet elevation tothe elevation of "free" delivery.(d) Total static head [HTs) is the vertical distance from thestatic supply surface to the free delivery elevation, i.e.,When a suction left exists,EirS = %SL+ HSD(2.11or, when a suctionhead exists,Krs = HSD - HssH(2.2)(e) Velocity head (HV) can be expressed as the distance watermust free fall to obtain a given velocity, i.e., HV = v2/2g .This is the amount of kinetic energy which exists as movingwater. Except at very high velocities, in low head systems,and for accurate testing, this head term is usually not greatenough to be significant.(f) Friction head (HF) is the amount of head needed to overcomethe resistance created by the system, including pipe skin,bends, intakes, valves, etc.(g) Pressure head (HP) need only be considered in systems wherethe pump discharges into a pressurized system, e.g., sprinkierirrigation. The pressure required by such a system at a givenelevation can be converted into an equivalent height of water,e.g., 1.0 psi = 2.31 ft of water.