2.2.7
[Gear Reducer
The pump, when required, shall be designed with a planetary gear unit
connecting the pump shaft to the motor shaft. Lubrication shall be of the
permanent type, and cooling shall be accomplished by the water flowing over
the pump/motor unit. A dual independent mechanical rotating shaft seal
system shall be provided between the motor, planetary gear system, and the
impeller.]
2.2.8
Air Vent
An air vent shall be provided, located as shown on the contract drawings,
and shall be a combination air and vacuum valve type. The valve shall be a
minimum 862 kPa 125 lb class and sized for the design flow rate. An
isolation valve shall be provided at the valve's inlet. Materials of
construction shall be cast iron for the valve body; stainless steel for the
internal linkage, float, and float stem; and Buna-N for the needle and
seat. The valve shall provide a dual function to release air during pump
start-up and to permit air to re-enter to break the vacuum during pump
shutdown.
2.3
DISCHARGE TUBE [AND DISCHARGE ELBOW]
2.3.1
General
The design, manufacture and installation of the discharge tube [and
discharge elbow] shall be in accordance with the pump manufacturer's
instructions. For purposes of performance and this specification it shall
be treated as part of the pumping unit. The discharge tube shall be of
such size to accommodate the dimensions of the pump supplied in accordance
with the manufacturer's requirements. It shall be permanently installed in
the pump sump as shown on the drawings. The design shall be such that the
pumps will be automatically and firmly connected to the discharge tube when
lowered into place and shall be in accordance with the pump manufacturer's
instructions. A locking device shall be provided that prohibits rotational
movement of the pump within the tube. The pumps shall be easily removable
for inspection or service without need to enter the pump sump. The pumps
shall not require any bolts, nuts, or fasteners for connection to the
discharge housing. Stiffening, guides, or other features shall be provided
at the pump support to ensure concentric positioning of the pump in the
discharge tube. Means shall be provided such that an effective seal is
obtained between the pump and discharge tube. Power cable penetrations
shall be watertight.
[A sole plate, as shown on the drawings, shall be installed. The entire
support assembly shall be designed to the requirements of Sections 13080
SEISMIC PROTECTION FOR MISCELLANEOUS EQUIPMENT and 15070A SEISMIC
PROTECTION FOR MECHANICAL EQUIPMENT.]
2.3.2
Design flanged joints to be airtight and watertight, without the use of
preformed gaskets, except that the use of a gasketing compound will be
permitted. Mating flanges shall be male/female rabbet type or doweled with
not less than four tapered dowels equally spaced around the flange.
Flanges and drill bolt holes shall be machined concentric with the
centerline, having a tolerance of plus or minus 1/4 of the clearance
between the bolt and the bolt hole. When fabricated from steel plate,
SECTION 15132A
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