a wall thickness not less than 0.625 mm 0.025 inch.
2.1.7.3
Insulation
Insulation shall be a granular mineral refractory material, highly
resistant to heat, and shall have a minimum specific resistance of 1,000
megohms per inch cubed at 535 degrees C 1,000 degrees F. Insulation for
the heating cable (winding wraparound type) type heaters shall be suitable
for a conductor temperature of 180 degrees C 356 degrees F.
2.1.7.4
Terminals
Terminals of the heater, including the leads, shall be watertight and shall
be provided with leads suitable for making connections to the drip-proof
terminal box provided in paragraph MOTOR TERMINALS AND BOXES. [The
terminal box shall be readily accessible through the crating so that
winding heaters can be energized while motors are in storage.]
2.1.8
Shafts
**************************************************************************
NOTE: Hollow shaft pumps shall be used whenever
possible, since they are more readily adjusted.
Pumps requiring large motors (above 1,000 hp) are
limited by the available motors. The exact motor
capabilities and sources of supply shall be
investigated when using hollow shafts with motors
above 1,000 hp. Solid shafts shall be used only
when the available motor designs require their use.
**************************************************************************
Shafts shall be made of high grade steel, finished all over, and of ample
size to drive the pumps under maximum load conditions. Shafts shall be of
[hollow] [solid] types as required by the pump manufacturer. See paragraph
GENERAL REQUIREMENTS for treatment against corrosion.
2.1.9
Bearings
2.1.9.1
Loading
Bearings shall be capable of withstanding all stresses incidental to the
normal operation of the unit [and the maximum speed of the pumping unit
when operating in the reverse direction].
2.1.9.2
Thrust Bearings
**************************************************************************
NOTE: If the thrust requirements exceed the standard
published ratings of commercially available
anti-friction thrust bearings, plate-type bearings
should be used. Should this condition exist, a
specification for plate-type bearings may be
obtained from CDR USACE (DAEN-CWE-E) WASH DC 20314.
**************************************************************************
Thrust bearings shall be of the antifriction type of either the ball or
roller type. Tandem or series bearing assemblies shall not be used.
Antifriction bearings shall conform to the requirements of ABMA 9 an d ABMA
11.
SECTION 16221A
Page 17
Previous Page
