Irrigation Professionals with questions about ... - Hunter Industries

(METERED SYSTEMS)Design Capacity and Working PressureWorksheetCALCULATING DESIGN CAPACITY AND DYNAMIC PRESSUREA. Record Site Information1 Static* Pressure at the Source (Main) PSI2 Net elevation Change (Source to POC) ± FEET (+uphill, - downhill)3 Pressure change due to elevation: Line 2 x 0.433 = PSI4 Static Pressure at POC: Line 1 +/- Line 3 = PSINumber/Length Size Type5 Service Line6 Delivery Line7 Water Meter8 Isolation Valves9 OtherB. Determine Design Capacity GPM WithFactor Restriction Restriction10 Pressure loss through Not to exceed 10% of availablethe water meter. PSI at the source(Line 1) GPM11 Volume through the Not to exceed 75% of maximumwater meter. safe flow of the meter. GPM12 Velocity through the Velocity not to exceed 7.5 fpsservice line. (Main to meter) GPM13 Design Capacity Lowest GPM of the three flows rates - lines 10, 11, and12. GPMC. Calculate Dynamic Pressure at Design CapacityPressure Losses from Source(City Water Main) to the POC14 Pressure loss in the Service Line PSI loss (per 100' ) x ft./100 = PSI15 Pressure loss in the Delivery Line PSI loss (per 100' ) x ft./100 = PSI16 Pressure loss in the Water Meter at design capacity = PSI17 Pressure loss in the Gate Valves: _____ Equivalence Factorx _____ PSI loss per 100' ofStandard Steel/100x _____ Number of Gate Valves = PSI18 Other pressure losses_____________________________ = PSI19 Pressure loss from the source to POC (add Lines 14 through 18) PSI20 Approximate Dynamic Pressure at Design CapacityStatic Pressure at the POC (Line 4 above)Subtract the PSI lost from the source to the POC (Line 19 )Approximate Dynamic Pressure at Design CapacityPSIPSIPSI