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|  MIL-P-18682D(SH)
3.2.6 Mounting.
3.2.6.1 Pump units shall be horizontally or vertically mounted, as specified
(see 6.2.1).
3.2.6.2 Each horizontal flexible coupled pump and separable driving unit,
complete with all appurtenances, shall be mounted on a common bedplate.
3.2.6.3 Bedplates shall be sufficiently rigid to permit handling, shipment,
and installation of the units on board ship, to minimize misalinement of the
assembled units; and such that normal distortion, weaving or vibration of the
supporting structures on board ships cannot cause misalinement between the pumps
and driving units.
3.2.6.4 Bearing and seating surfaces of bedplates shall be finish machined.
3.2.6.5 Each component part of an assembled flexible coupled unit supported
directly by a bedplate shall be doweled thereto to facilitate reassembly and main-
tenance of alinement, except that final doweling of the driver shall be performed
by the installing activity after final installation. The manufacturer shall
furnish a warning plate indicating the above.
3.2.6.6 Vertical pumps shall be base mounted or center of gravity mounted.
The base and support bracket shall have provisions for bolting to a foundation.
Pumps which are resiliently mounted shall be supported as close to the center of
gravity as practical.
3.2.7 Bearings. Suitable bearings shall be installed in each pump unit
for counteracting (a) any unbalanced hydraulic or mechanical thrust in either
direction and (b) the fact that rolling, pitching, listing and trim, and the
athwartships, fore and aft, and the vertical distance from the pump to the
ship's rolling and pitching center may introduce loads even though the unit is
in hydraulic balance (see 6.2.1). The contractor shall calculate the resulting
static and dynamic loads on the bearings and certify that the bearings are suit-
able for this loading (see 6.2.2).
3.2.7.1 Radial bearings.
3.2.7.1.1 Radial bearings may be of the hydrodynamic or rolling contact
type. If specifically approved by the design review agency (see 6.4), hydro-
static bearings may be used.
3.2.7.1.2 Except as otherwise approved by the design review agency,
rolling contact bearings shall be of the ball type in accordance with FF-B-171.
Roller bearings may be recommended if use of ball bearings is impractical. If
approved, roller bearings shall be in accordance with FF-B-185 or FF-B-187.
Rolling contact bearings shall be selected to result in a minimum B-10 life of
10,000 hours calculated in accordance with FF-B-171, FF-B-185, or FF-B-187.
3.2.7.1.3 Rolling contact bearings specifically selected for quiet opera-
tion in accordance with MIL-B-17931 shall be used for pumps for submarine appli-
cation and for surface ships where required to meet special noise requirements
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