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CITY OF ANAHEIM DRAINAGE MANUAL FOR PUBLIC AND PRIVATE DRAINAGE FACILITIES APPENDIXES AUGUST 2005 Appendix B Sample Sump Pump Design ---PAGE BREAK--- h 2.79 ft1 = h L f⋅ f 0.0397 ft0 = f V 1.318 C ⋅ R0.63 ⋅ 1.852 1 sec1.852 ft0.685 ⋅ ⋅ V 7.234 ft sec = V Q π 4 D2 R 0.083ft = R D 4 Q 0.63126 ft3 sec = or Q 283.33 gal min C 150 L 70.36ft D 4in 4" P.V.C., L = 70.36ft, C = 150 1. Force Main: City of Anaheim Department of Public Works Development Services Division Grading Design Manual Appendix H - Sample of Sump Pump Design I. Calculation of Total Dynamic Head A. Static Head: (Maximum force main elevation - minimum wetwell elevation) Elevation of force main discharge: Elev_FM 100.24ft Elevation of floor of wet well: Elev_WW 89.07ft Pump Off Level = 0.5 ft above floor: Then Static Head: H_ST Elev_FM Elev_WW − 0.5ft − H_ST 10.67ft = B. Friction Head: Use Hazen-Williams Equation h L f⋅ f f V 1.318 C ⋅ R0.63 ⋅ 1.852 C V = Velocity (fps) = Q/A C = Hazen-Williams Coefficient R = Hydraulic Radius = Area/ Wetted Perimeter = D/4 SumpPump.mcd 1 of 3 8/10/2005 4:17 PM ---PAGE BREAK--- 2 ea 22.00 ft PVC, 4" 1 ea 1.50 ft Tee, 4" x 4" x 4" 1 ea 17.00 ft Reducer, 3" x 4" 1 ea 0.35 ft Total L 72.85ft h L f⋅ , f 0.06 ft0 = h 4.37 ft1 = Total Dynamic Head = Static Head + Friction Head = Static Head + Force Main + Spool + Fittings = 7.34 ft + 2.79 ft + 0.18 ft + 4.37 ft T.D.H. = 14.68 ft Use T.D.H. = 14.7 ft 2. Spool on Force Main: 4" D.I.P., L = 3.00ft, C = 120 D 4in L 3ft C 120 R 0.083ft = V 7.234 ft sec = f V 1.318 C ⋅ R0.63 ⋅ 1.852 1 sec1.852 ft0.685 ⋅ ⋅ f 0.06 ft0 = h L f⋅ h 0.18 ft1 = 3. Fittings (Valves and Elbows using Equivalent Length Method): Values for Equivalent Length taken from: Crane Co., “Flow of Fluids through Valves, Fittings and Pipe”, Crane Technical Paper No. 410, New York, 1991 EQUIVALENT LENGTH OF STRAIGHT PIPE DESCRIPTION QUANTITY PVC to DIP, fitting 4" x 6" 2 ea 1.00 ft Vertical Swing Check Valve, 4" 1 ea 31.00 ft 90 Elbow, 4" SumpPump.mcd 2 of 3 8/10/2005 4:17 PM ---PAGE BREAK--- II. Calculation of Float Setting in Well to Satisfy Pumps: Well Storage Dimensions (plan dimensions): L x W = 4' x 4' Storage per 1 foot rise within well given by: Storage 4 ft ⋅ 4⋅ ft ⋅ 7.48 gal ft3 ⋅ ⋅ Storage 119.68 1 ft gal = Float Setting in Well: Rise Q Storage Q 283.33 gal min = Rise 2.367 ft min = Assuming that the pump cycle is 60 seconds: Float Rise 60 ⋅ sec Float 2.37 ft = Then, 2.37 feet is the float setting between lead pump on and off position in well to satisfy pump cycle. Note, the recessed area of the well was not considered in figuring the float setting due to displacement of the pumps and fittings. SumpPump.mcd 3 of 3 8/10/2005 4:17 PM