Laserfiche WebLink
.�FNJFiv NO/� F.T <br /> -7 BFD�c om I) <br /> PUMP SELECTION PROCEDURE <br /> 9-3'9L <br /> A. Determine pump capacity: <br /> r <br /> 1 . Minimum suggested is 600 gallons e per hour (l0 Rpm) - <br /> to stay ahead of water use rat <br /> 2. Maximum suggested .for delivery to a drop box of a home <br /> system is- 2700 gallons per hour (45 gpm) to prevent <br /> buildup of pressure in drop box <br /> 3. Use value from design of pressure distribution system <br /> SELECTED PUMP.CAPACITY . . . . . . . . . . . . . . . . SS <br /> -----._. gpm <br /> B. Determine head requirements: <br /> 1 . Elevation difference between pump and point of discharge _ <br /> 2• If pumping to a pressure distribution system, add 5 feet '`— feet <br /> for pressure required at manifold <br /> 3. Friction loss .? feet <br /> a. Enter friction loss table with gpm and pine diameter. <br /> Read friction loss in feet per 100 feet from page F-18. <br /> F. L. = y. 7� ft/100 ft <br /> b. Determine total pipe length from pump to discharge <br /> point. Add 25 percent to pipe length for fitting <br /> loss, or use a fitting loss chart. Equivalent pipe <br /> length = 1.25 times pipe length = 1.25 x 12- 56' <br /> C. Calculate total friction loss by multi.plying - �.5feet <br /> friction loss it' ft/100 ft by equivalent pine <br /> length. <br /> Total friction loss = V. 7 6 __ <br /> 4. Total head required is the sum of lavation d f6 feet <br /> ifference, <br /> special head requirements, and total friction loss. <br /> TOTAL HEAD . . . . . . . . . . . . . . . . . . . . . . feet <br /> C. Pump selection <br /> 1 • ! A pump must be `selected to deliver at least S.S' <br /> with at least - gpm <br /> /�. feet of total head. <br /> I). To maximize pump life select sump size for 4 to 5 pump <br /> operations per day. <br /> I:. Calculate drainback <br /> I • Determine toLnl.' pipe lenl;th, 2_ ,5 feat2 . . <br /> Determine liquid volume ofPiPepe, - + <br /> _ 7. gallons per <br /> 100 feet. (See page E-18) <br /> 3. Multiply length by volume: Drainback quantity = <br /> 5 feet x I7,y gallons/1.00 ft - Z/ JP gallons <br /> 4 . Suggested drainback quantity is 10 percent of pumped .quantity. <br /> A larger drainback percentage will decrease pump station <br /> efficiency slightly but pumping energy costs are usually a <br /> relatively small part of the total hour:ehold energy costs. <br />