MIL-HDBK-1005/9A
b) Use reciprocating positive displacement or screw
pumps to transfer oily wastewater to treatment unit or
equalization facility. Maximize size of wet well and select a
number of pumps and an operating schedule to minimize surge
effect of pump off-on cycle on downstream oil-water separators.
Consider variable speed drives on transfer pumps.
c) If rotary displacement or centrifugal pump is used,
design for low speed (≤900 rpm) to minimize mechanical
emulsification.
(1) Maximize size of wet well and select the
number of pumps and an operating schedule to minimize surge
effect of pump off-on cycle on downstream oil-water separators.
(2) Consider the use of a pump control valve and a
surge tank with control orifice to throttle discharge to oil-
water separator. Consider variable speed drives on transfer
pumps.
3.8.4
Gravity Flow Collection System. Collection piping
should be sized for the following flows. Procedures for design
of ship oily waste collection pipelines are based on Qmain and
Qlateral. The design objectives are to determine the diameter of
pier laterals and the pier main. The design procedure is as
follows:
a) Facility Daily Flow. For design purposes,
determine if the activity is a "small" or "large" facility.
Determine the number and classes of ships present during maximum
holiday berthing and average daily berthing. Determine Qdaily by
Equation 3 or 4. Determine Qmaximum by Equation 5 for large
facilities.
106
Previous Page
