MIL-HDBK-1005/9A
b) Sizing of Pier Main and Laterals. Determine
length of pier main, pier riser elevation, deck riser elevation,
and ship discharge pressure for each ship class berthed at pier.
Determine the diameter of the pier main for Qmain flow rate at
design velocity of 2 fps (0.6 m/s) for gravity system. Maintain
pipe velocity less than scouring velocity recommended by pipe
manufacturer. The minimum velocity will be zero since flow is
intermittent. Pressurized systems should be sloped to drain to
prevent freezing, fluid stagnation, and for cleaning purposes.
(1) Calculate the friction loss in the pier main
at the Qmain flow rate using Equation 8 for flow of marine diesel
fuel with viscosity at lowest expected ambient temperature.
(Note: Equation first appears in English (IP), then metric
(SI)). Determine design viscosity from Figure 10. Assume Hm
occurs at each main-lateral intersection as a back pressure
against berthed ship's bilge pumps.
Hm = [f(L/D)(Qmain/Dmain2)2]/g
EQUATION (IP):
(8)
or
Hm = [f(L/D)(Qmain/Dmain2)2/g] [79,217]
EQUATION (SI):
where
Hm
=
head loss in pier main, ft (kPa)
f
=
Darcy-Weisbach friction factor. See Figure
IIIA-3 in Engineering Data Book by the
Hydraulic Institute
L
=
length of pier main from pier end to free
discharge point, ft (m)
Dmain
=
pier main diameter, in. (cm)
32.2 fps2 (9.81 m/s2)
g
=
(2) Calculate the maximum Qlateral for all ship types
at maximum holiday berthing plan. Determine the diameter of the
pier lateral at maximum Qlateral flow rate at design velocity of 5
to 7 fps (1.5 to 2.1 m/s). Maintain velocity less than the
maximum scouring velocity recommended by pipe manufacturer.
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