MIL-HDBK-1005/9A
c) Suction Inlets. Provide tapered inlet for vortex
suppression. Determine required submergence above highest open
point of suction inlet based on the entrance velocity.
Interpolate from the following table. Limit entrance velocity
to 5 fps (1.5 m/s).
Submergence
Entrance Velocity
(ft (m))
(fps (m/s))
1.0 (0.30)
2 (0.61)
1.5 (0.46)
3 (0.91)
2.0 (0.61)
4 (1.22)
2.6 (0.63)
5 (1.52)
d) Ventilation. Provide a 4-inch (102-mm) minimum
diameter vent with return bend and stainless steel bird screen.
2.5.3.7
Dry Wells (for other than submersible pump stations).
a) Size. Keep dry wells to the minimum size
consistent with safe and convenient operation and with allowance
for possible expansion.
b) Type of Pump. Use vertical pumps to conserve
space (unless special conditions dictate otherwise).
c)
Sumps.
Provide the following:
(1) Minimum 20 gpm (1.3 L/s) capacity.
(2) Check valve in horizontal run.
d) Hoisting Facilities. Provide installed or
portable hoisting facilities consistent with the size of the
installation. Provide lifting eyes for a portable hoist.
e)
Ventilation.
Provide positive ventilation.
f) Provide potable water (if available) to dry well
for general maintenance use.
2.5.3.8
Alarms. Provide both audible and visual alarms for
wet well and pumps. Wet wells should have both high and low
level alarms; provide pumps with flow switch alarms for pump
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