greater. Self-supported enclosing tubes 4500 mm (15
ft) length or greater should have external supports.
The enclosing tube is split when pump size is 1800
mm (72 in.) or larger.
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Provide shaft enclosure to cover intermediate shaft and coupling. It
[shall be placed in tension or ]shall be rigid enough to be
self-supporting.[ External supports or bracing located in pump water
passage shall not be used for support of the enclosing tube unless
necessary to support intermediate bearings or indicated to be necessary or
advantageous by dynamic analysis required in paragraph DYNAMIC ANALYSIS.
Consider effect of external supports, including rubber inserts, in the
dynamic analysis required in paragraph TEST, INSPECTIONS, AND
VERIFICATIONS, subparagraph DYNAMIC ANALYSIS.] Design enclosure to be
watertight and for easy assembly and disassembly in the field.[ Enclosure
shall be split longitudinally to permit easy removal without removing or
disassembling pump shaft.] Enclosing tubes constructed with screw type
joints and using tension in tube to hold alignment, shall be constructed to
prohibit tension tube from unscrewing when packing gland adjustments are
made. Provide shaft enclosure for grease-lubricated pumps with a drain
having a shut-off valve located outside of the to permit draining enclosure
between operation periods. Locate drain at bottom of shaft enclosure. On
oil-lubricated pumps, the enclosing tube below lowest bearing and above oil
seals shall be fitted with an oil/water drain line to the outside of pump.
Drain line shall have a check valve outside of pump to preclude entrance of
sump water.
2.2.11
Lifting Lugs
Furnish major pump components with lifting lugs or eye bolts to facilitate
handling. Design and arrange lugs or bolts to allow safe handling of pump
components singly or collectively as required during shipping,
installation, and maintenance.
2.2.12
Guide Bearings and Seals
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NOTE: Grease lubrication can be used with all size
pumps. Oil lubrication may be used in pumps having
discharge diameters of 900 mm (36 in.) or smaller.
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2.2.12.1
Guide Bearings
Provide pump with sleeve-type bearings designed for [grease][oil]
lubrication. Bearing shall have a bronze lining in contact with shaft
journal and shall be replaceable type. Arrange bearing liner for maximum
distribution of [grease][oil] for lubrication of journal surface. Bearings
shall have a surface finish of 0.80 m 32 microinches rms or better to
match journal finish. Since pumped water may contain some fine sand and
silt in suspension, give special attention to the design and selection of
bearing parts, especially seal rings, to preclude entrance of foreign
material between bearing and journal due to differential water pressure.
2.2.12.2
[Oil][Grease] Lubrication Shaft Seals
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NOTE: Select appropriate alternate paragraph.
SECTION 15131A
Page 34
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