Septic System Approval - Laserfiche WebLink

Home Browse Search

i'-l.,l PUMP SELECTION PROCEDUTI _ A. Determine pump capacity: 1. Minimum suggested is 600 gallons per hour(10 gpm) to stay ahead of water use rate. 2. Maximum suggested for delivery to a drop box of a home system is 2,700 gallons per hour(45 gpm)to prevent build-up of pressure in drop box. 3. Use value from design of pressure distribution system. SELEC'T'ED PUMP CAPACITY 7 °1 gpm i APIs Len gth B.Determine head requirement= Point of D'quc1nar 1. Elevation difference between pump and point of discharge. gy,,,� i a pa feet 9" 2. If pumping to a pressure distribution system,add five feet for pressure required at manifold , -.. ...-.:feet F-18b 3. Friction loss . 1.5 inch 2.0 inch 3.0 inch a. Enter friction loss table with gpm and pipe diameter. um Primula t,w per too rnac pops Read friction loss in feet per 100 feet from page F-18. 10 0.69 0.20- 0.F.L= 3. S- ft./100 ft of pipe •12 1.8 o 8 : b. Determine total pipe length from pump to discharge 16 1.63 0.48 point. Add 25 percent to pipe length for fitting 18 2.03 0.60 loss,or use a fittingloss chart. Equivalent20 2.47 10.1173 0.11 pipe 25 3.73 1.11 0.16 length-125 times pipe length a 30 5.23 1.55 0.23 • I (-J x 125.=, J- D feet 35 7.90 206 0.30 c. Calculate total friction loss multiplying l 40 1 .73 2.64 0.3 9.73 g 45 144.73 3.28 0.48 friction loss in ft/100 ft by equivalent pipe length. 50 3.99 0.58 Total friction loss: D D ( x - _ +100 in few 60 5.60 0.82 4. Total head required is the sum of elevation difference, special head requirements,and total friction loss. ?Q + S + s' (1) (2) (3d TOTAL HEAD 4 a feet C. Pump selection • 1. A pump must be selected to deliver at least ;�,gpm (Step A)with at least D-� feet of total head(Step B). a nimwtm acwl.°c rows M, GALLONS PER 04Y mimosa TY/e or FC31ocl.c a OF D. Total Pumpont Volume 2 Soo u, 1 p Sou 1. To maximize pump life select sump size for 4 to 5 pump operations per day. , '4 `°° 'O° 21111 7 Ser gpd+4-. 1 c gallons per dose 5 i50 4 50 2114 IN4Le r. OO 375 xis s sec525 332 -- 2. Calculate drainback r Imo - sec ro .. 1. Determine total pipe length, 4.1.:,,, .feet. s 1=00 '75 ate Ca,,,,,,,,,,r 2. Determine liquid volume of pipe, I Ce gallons per 100 feet. (see page F-18) F-18a 3. Multiply length by volume Drainback quantity= pips diameter(inches) c,llons per 100 feet 1sc.- feet x fid,gallons/100 ft._ TO gallons. 1 4.49 'Suggested drainbacic quantity is 10 percent of pumped quantity. A larger drainback 1.25 7.77 percentage will decrease pump station efficiency slightly but pumping energy costs are usually a relatively small part of the total household energy costs. 12.5 17.431. 3. Total pump out volume equals dose volume+drainback 2.5 24.87 I ce gallons per dose+ 3 0 gallons= a) cr Total Gallons 3 38.4 4 66.1 . 1