MIL-HDBK-1022A
4.3.2.2
Off-Loading Drop Tanks. The introduction of air
into a fuel receiving system poses extreme hazards which can
result in fire and/or explosion. Hazards are compounded when
an air/fuel mixture is passed through receipt
filter/separators where static electricity is generated and
ignition can occur. For facilities with the capability to
off-load several tank trucks at once or where newer tank
trucks with multiple hoses are connected to multiple isolated
compartments, consider providing an underground, gravity-type,
receiving tank with deepwell turbine transfer pumps and level
controls. For smaller systems of one or two tank trucks,
consider providing a low profile, aboveground, receiving tank
with a centrifugal transfer pump. For either case, provide
level sensors to control the transfer rate. See Facility
Plate No. 005.
4.3.2.3
Equipment Required
a) Where tank trucks or tank cars are off-loaded
into aboveground tanks, provide centrifugal pumps configured
to provide automatic air elimination, one for each tank truck
or tank car that is to be off-loaded simultaneously, at an
average capacity of 300 gpm (19 L/s). Off-loading systems
designed in accordance with NAVFAC Drawing No. 1404005, i.e.,
with a receiving vessel and variable rate pump flow control
can off-load at rates up to 600 gpm. Where pumps are
required, provide at least two pumps to allow continued
operations if one is out of service. Where tank trucks or
tank cars are off-loaded into underground tanks, pumps will
not normally be required.
b) Provide 4-inch (100 mm) diameter by 10-foot (3 m)
long lightweight reinforced vacuum rated off-loading hoses and
covered hose storage racks for each off-loading position.
Ensure that all swivels are non-lubricated aluminum or
stainless steel in-line repairable type.
c) Equip each tank truck off-loading position with
an automatic, self-monitoring ground verification unit with a
lockable bypass. If grounding is not verified and there is an
off-loading pump dedicated to that position, ensure the unit
prevents the pump from starting. If the pump is not
dedicated, ensure an alarm sounds if the off-loading valve is
opened prior to grounding verification. Include a separate
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