Service Contract No 2007 / 147-446 - Swaziland

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5 F I E L D E V A L U A T I O N O F S P R I N K L E R I R R I G A T I O NS Y S T E MPhase onePhase twoBlock Area (Ha) 56 95Type of sprinkler system Dragline Irrigation System Dragline Irrigation SystemName of Designer A.J. Nyman S.I.I.Name of contractor A.J. Nyman S.I.I.Design Measured Design MeasuredSprinkler spacing (m x m) 18 18 18 17.5 - 19Lateral spacing (m) 54 35 – 62 54 200Stand pipe height (m) 3 3 3 3Pressure regulator Yes <strong>No</strong> Yes <strong>No</strong>Dragline diameter (mm) 20 20 20 20Dragline length (m) 45 54 2 100Maphobeni Farmers Association Report - 2009 Page - 33 -
5 . 1 P r e s s u r e r e a d i n g sThe following pressure readings were taken:5.1.1 P r e s s u r e a t h y d r a n tPressure controlThe lateral of the irrigation system that was installed by S.I.I. (phase two) are equipped withmechanically chocked hydraulic valves. Pressure-regulating pilot are not installed. Phase onelaterals are equipped with mechanical valves; there are no hydraulic valves in this phase.Pressure-regulating pilots (on the valve head) reduce a higher inlet pressure to a lowerconstant outlet pressure, regardless of fluctuating flow rates and or varying inlet pressure.The pilot would sense down-stream pressure and modulates open or close, causing the mainvalve to throttle, thus maintaining constant delivery pressure.When down –stream pressure falls below the pilot setting, the pilot and main valve wouldmodulate open to increase pressure and maintain pilot setting. When downstream pressurerises above the pilot setting, the pilot and main valve would throttle close to decreasepressure and maintains pilot setting. The pilot has an adjusting screw to preset the desiredpressure.Figure 16. Lateral hydrant valveMaphobeni Farmers Association Report - 2009 Page - 34 -
Page 1 and 2: Restructuring and DiversificationMa
Page 3 and 4: DISCLAIMERThe contents of this repo
Page 5 and 6: 5.2 Delivery tests ................
Page 8 and 9: LIST OF APPENDICESAppendix 1: SEB u
Page 10 and 11: 1 I N T R O D U C T I O NAssociatio
Page 12 and 13: pumps. 2 x Howden 100-400 in the ri
Page 14 and 15: 3.1.2 R e v i e w o f C o n t a c t
Page 16 and 17: 9 SCHEDULE OF BLOCKS THAT IRRIGATE
Page 18 and 19: Maphobeni Farmers Association Repor
Page 24 and 25: Based on equation 1 above the flow
Page 26 and 27: ReducersThe inlet on the pump sucti
Page 28 and 29: d1.5d0.5dd3d 3d 1.5dFigure 9. Spaci
Page 30 and 31: hf6375kQ4d2……………………
Page 32 and 33: Table 1. Pump and motor specificati
Page 34 and 35: Table 2. Irrigation pumps evaluatio
Page 36 and 37: Phase two river pump station‣ Pum
Page 38 and 39: Filters: 3%Capital Recovery Rate (C
Page 40 and 41: 4.3.1 M a i n l i n e s i z eThe So
Page 44 and 45: 5.1.2 S p r i n k l e r p r e s s u
Page 46 and 47: 0 L/4 L/2 3L/4 LL3L/4LL/2Test block
Page 48 and 49: Phase two booster Pumps running und
Page 50 and 51: The installation of this unit (on t
Page 52 and 53: Old AgePhase one of the irrigation
Page 54 and 55: The effects of different nozzles/em
Page 56 and 57: Interest RatesIt can be argued that
Page 58 and 59: 6 . 2 M a n a g e m e n t P r a c t
Page 60 and 61: 6 . 3 M a i n t e n a n c e S u r v
Page 62 and 63: 7 C O N S T R A I N T S T O E F F I
Page 64 and 65: phase one and two was found to be 1
Page 66 and 67: 8 R E C O M M E N D A T I O N STo e
Page 68 and 69: OVERALL MANAGEMENT AND MAINTENANCEM
Page 70 and 71: 10 L I T E R A T U R E R E F E R E
Page 72 and 73: 11 P R O D U C T I N F O R M A T I
Page 86 and 87: SEB usage for River pump station Ph
Page 88: Appendix 2: capital recovery factor

Service Contract No 2007 / 147-446 - Swaziland

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