Laserfiche WebLink
�� �Fa�c�aoiN ,s r-15 <br /> PUMP SELECTION PROCEDURE <br /> A. Determine pump capacity: <br /> 1 . Minimum suggested is 600 gallons per hour (10 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 . . . . . . . . . . . . . . . . 3S. S gpm <br /> B. Determine head requirements: <br /> 1 . Elevation difference between pump and point- of discharge �f' �_` feet <br /> 2. If pumping toa pressure distribution system, add 5 feet <br /> for pressure required at manifold . . . . . . . . . . S feet <br /> 3. Friction loss. <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. = 6. 96 ft/100 ft <br /> b. Determine total pipe length from pump to discharge <br /> point. Acid 25 percent to pipe length for fitting <br /> loss, or use a fitting loss chart. Equivalent pipe <br /> length = 7.•25 times pipe length = 1. 25 x 1476 _ /_?_S feet <br /> C. Calculate total friction loss by multiplying <br /> friction loss in ft/100 ft by equivalent pine <br /> length. <br /> Total . friction loss feet <br /> 4. Total head required is the sum of elevation difference, <br /> special head requirements, and total friction loss. <br /> + S + F. 7 _ <br /> TOTAL 1?;;AD . . . . . . . . . . . . . . . . . . . . . . �;��• f ee t <br /> C. Pump selection <br /> 1. A,.pump must be selected to deliver, at least gpm <br /> with at least 17, 7 feet of total head. <br /> D. 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, /OQ feet . <br /> 2. Determine •liquid volume of pipe, _ /p_ Sn" gallons per <br /> 100 feet. (See page E-1$) <br /> 3. Multiply length by volume: Drainbacic quantity = <br /> /GO feet x /!J. Sa' gallons/100• -ft 142. 4 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 household energy costs. <br />