MIL-HDBK-1164
Table 23
Flow Rate and Number of Hydrant Outlets Required to Flush Water Mains with 40 psi
(280 kPa) of Pressure
Number of 2.5-in. (65-mm)
Pipe Diameter
Flow
inches
(mm)
gpm
(Lps)
Hydrant Outlets
4
(100)
100
(6)
1
6
(150)
200
(13)
1
8
(200)
400
(25)
1
10
(250)
600
(38)
1
12
(300)
900
(57)
2
16
(400)
1,600
(100)
2
b)
Flushing Plan. Draw up a flushing plan to ensure complete
cleaning of the system:
(1)
Using distribution maps, prepare a list of hydrants and
blowoffs to be opened in an order that will flush the system from source to ends.
(2)
List, in correct order, valves to be closed and opened for
each flushing point.
(3)
If service in any section will be disrupted by the plan,
arrange to flush it at night. Notify heating plant and fire fighting personnel in such
sections.
c)
Operating Guides
(1)
Remove service meters from the section being flushed.
(2)
Flush each pipe section until water is reasonably clear.
(3)
Take care not to damage unpaved roads, walks, or
improved grounds. If necessary, use a section of lightweight pipe to direct flows so that
damage does not occur.
(4)
Place all valves in normal operating position before
proceeding to the next flushing point.
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