2.2.7.3
Pumps Discharge Diameter
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NOTE: A manhole is used if the pump has a shaft
enclosing cover that can be removed without
disassembly of the pump.
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Pumps having discharge diameter greater than 1500 mm 60 inches. shall
contain a manhole. Structural steel bracket with a platform of
raised-pattern floor plate similar to the one(s) shown on contract drawings
shall be provided as a support for maintenance personnel for access to pump
through a manhole. Provide manhole 600 by 750 mm 24 by 30 inches., or
largest practicable size with gasketed cover, in the column above diffuser
bowl. Provide jack bolts in cover together with eye bolts to facilitate
removal.
2.2.7.4
[Formed Suction Intake]
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NOTES: Select appropriate alternate paragraph.
Alternate 1 should be used when a rectangular sump
is designed using criteria established by U.S. Army
Engineer Waterways Experiment Station.
The use of a Formed Suction Intake (Type 10),
Alternate 2, is determined during the design phase
of the station/pump. The Government will furnish
all dimensions and be responsible for the design.
The FSI was developed by WES and is now included in
HI 9.8.
The sump floor elevations should be determined in
the design of the pumps/station. The impeller datum
elevation should allow the necessary submergence as
and verified with pump manufacturer's data.
The Designer should contact at least 3 pump
manufacturers early in the project design phase to
verify the Designer's pump size estimate. Normally
the eye of the impeller is located at minimum sump
elevation, and the geometry of the FSI determines
sump floor elevation. The early verification is
important for pump house structural design, because
FSI hydraulics are very sensitive to change, and the
pump diameter determines the dimensions of the FSI.
In designs where the FSI is not constructed of
concrete, it is recommended that all materials
indicated, or combination of these materials, should
be specified. A hatch in the operating floor is
generally provided in each pump bay to permit the
placement of the FSI sections into the sump. If the
station design/size does not have space for a hatch,
then the opening for the pump is used for placement
and removal of the FSI or is designed so that it can
be removed using the sump gates and trash rack. The
SECTION 15131A
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