HomeMy WebLinkAboutPump Selection Procedure F-15K-15
PUMP SEl.KCTlOtl !>R0':K!)'JP.!-:
A. DcCt^rmiiu; pump capacity:
1 .
2.
i.
Minimiiw sugRCsCc-il is 600 gal Ions pi:r liour (10 gpin)
to Htav ahead of water u::e rate
Maximum suggested for delivery to a drop box of a home
system is 2700 gallons per hour (45 gpm) to prevent
buildup of pressure in dro|) box
Use value from design of pressure distribution system
SEl.ECTED PUMP CAPACITY 3^.5 gpm
O feet
5 feet
B. Determine head requirements:
1. Elevation difference between pump and point of discharge - -
2. If pumping to a pressure distribution system, add 5 feet
for pressure required at manifold . . . . . . . . . . . . . . .
3. Friction loss
a. Enter friction loss table with gpni and pipe diameter.
Read friction loss in feet par 100 feet from page F-18.
F. L. = 96 ft/100 ft
b. Determine total pipe length from pump to discharge
point. Add 25 percent to pipe length for fitting
loss, or use a fitting loss chart. Equivalent pipe
length =1.25 times pipe length = 1.25 x 7^_ _“- - -O <5L
c. Calculate total friction loss by multiplying
friction loss in ft/IOO ft 1>V equivalent pine
Total friction loss = x _ _ _“ - - - - - - - -.Cr../-
Total head required is the sum of elevation dilference,
speci.il head requirements, and total friction loss.
O + 5_ _ _ + /
feet
<•.
TOTAL DEAD
C. Pump selection
//. / feet
1.A pump must be selected to deliver at least _7.5'.
with at least //. / ft-ot of total head.
gpm
D.To maximize pump life select sump size for 4 to 5 pump
operations per day.
E. Calculate drainback
I .
2.
3.
f eet.
gallons per
Determine total pipe length, _ _ _ _ _
Determine liquid volume of pipe, _ _
100 feet. (See page E-18)
Multiply length by volume: Drainback quantity =
feet X gallons/100 ft =_ _ _ _ _ _ _gallons
Suggested drainback qu.antity is 10 percent of pumped quantity.
A larger drainback percentage will decrease pump station
efficiency slightly but pumping energy costs arc usually a
relatively small part of the total household energy costs.