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h/orr F,f <br /> ' � �BFORoDm,-S' �RF-DFl/G.v /c�2 '7 BFDRaoml, <br /> PUMP SELECTION PROCEDURE <br /> A. Determine pump capacity: <br /> 1 . Minimum suggested is 600 gallons per hour (1.0 gpm) <br /> to stay ahead of water use rate <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 . . . . . . . . . . . . . . . . gpm <br /> ,�$ <br /> T3. Determine head requirements: <br /> 1 . Elevation difference between pump and point of discharge _ _� feet <br /> 2• If pumping to a pressure distribution system, add 5 feet - <br /> for pressure required at manifold . <br /> 3. • Friction loss S__ feet <br /> a. Enter friction loss table with gpm and pipe diameter. <br /> Read friction.loss in feet per 100 feet from page F-18. <br /> F. L. = y. 76 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 Ape <br /> length = 1. 25 times pipe length = .1. 25 xZ <br /> c. Calculate total friction loss by multiplying - �.5.6.__ feel <br /> friction loss i.n ft/100 ft by equivalent pine <br /> length. <br /> Total friction loss76 oD x �S6 <br /> 4. Total head required is the sum of elevation difference, 7� y feet <br /> {-.-- <br /> special head requirements, and total friction .loss. <br /> -�_ + .�_ + <br /> TOTAL. NFAD . . . . . . . . . . . . . . . . . . . . . . feet <br /> C. Pump selection <br /> 1 . , A ,pump must be °selected Lo deliver at least ss' <br /> /_ gpm <br /> with at least <br /> /�. feet of total head. <br /> U. To maximize pump life select sump size for 4 to 5 pump <br /> operations per day. <br /> E. Calculate drainback <br /> 1 . Determine total.' pipe length, 2 ,> Feet . <br /> _ . Determine liquid volume of pipe, _ 7, - gallons her <br /> 100 feet. (See page E-1$) <br /> 3. Multiply length by volume: Drainback quantity = <br /> /2.S feet x /7.y gallons/3.00 £t /. OF 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 hous.ehol-d energy costs. <br />