sample of sump pump design pdf - anaheim
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CITY OF ANAHEIM DRAINAGE MANUAL FOR PUBLIC AND PRIVATE DRAINAGE FACILITIES
APPENDIXES
AUGUST 2005
Appendix B
Sample Sump Pump Design
h 2.79 ft1=
h L f⋅:=
f 0.0397 ft0=f
V
1.318 C⋅ R0.63⋅
1.852
1sec
1.852
ft0.685
⋅
⋅:=
V 7.234ft
sec=V
Q
π4
D2
:=
R 0.083 ft=RD
4:=
Q 0.63126ft
3
sec=orQ 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 AnaheimDepartment of Public Works
Development Services Division
Grading Design Manual
Appendix H - Sample of Sump Pump Design
I. Calculation of Total Dynamic Head (T.D.H.)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 10.67 ft=
B. Friction Head:Use Hazen-Williams Equation
h L f⋅:= f fV
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
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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 0.083 ft=
V 7.234ft
sec=
fV
1.318 C⋅ R0.63⋅
1.852
1sec
1.852
ft0.685
⋅
⋅:= f 0.06 ft
0=
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 LENGTHOF STRAIGHT PIPEDESCRIPTION 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"
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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⋅ 7.48gal
ft3
⋅
⋅:=
Storage 119.681
ftgal=
Float Setting in Well:
RiseQ
Storage:= Q 283.33
gal
min=
Rise 2.367ft
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 inwell to satisfy pump cycle.
Note, the recessed area of the well was not considered in figuring the floatsetting due to displacement of the pumps and fittings.
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