constant-level oiler with level indicator or easily accessible grease
nipples as appropriate to the bearing design. Provide mechanical or
centrifugal shaft seals conforming to paragraph entitled "Centrifugal
Pumps." Furnish one spare set of shaft seals for each pump. Support
frames for all vertically split pumps shall be fabricated of structural
steel and heavy plate extending the full length of pump and driver. Design
to adequately support equipment under operating conditions without grout
fill inside the frame. Frame shall not be covered with a thin steel plate
which requires grouting under the plate, but the frame may be filled with
concrete as required for drainage. Grout shall be required under the basic
frame only. Contractor to provide minimum 25 mm one inch pipe drain in the
perimeter of the frame. Drawings shall indicate the required concrete fill
lines for proper drainage. The pump shall be dowelled shall be dowelled to
the frame in the shop; the driver shall be dowelled in the field. Furnish
bolts or screws for attaching pumps and motor drives to the support frame.
Frames shall have grouting holes, 100 mm 4 inch minimum size, to facilitate
proper grouting, if area is covered. Materials of construction shall be as
specified below.
Part Name Material
Casing
Cast iron or steel, ASTM A 48M ASTM A 48
with replaceable rubber liners
Impeller
Soft rubber on steel skeleton
Shaft
Heat-treated carbon, or stainless steel,
ASTM A 276, Type 410
Shaft Sleeve
Ceramic faced
Baseplate Steel, ASTM A 36/A 36M
2.10.1.3
Vertically Split-Case Pumps
Vertically split case pumps shall be end suction, single-stage,
single-suction centrifugal, of the volute type. Pumps shall be bronze
trimmed, and designed for continuous operation at specified operating
conditions. Pumps shall be frame-mounted with pump shaft carried on its
own bearings with flexible coupling between pump and motor. Pump
orientation to fit piping arrangement. Pump casing shall be split into
suction inlet assembly and pump assembly. Design for ease of disassembly,
allowing the rotating assembly and bearing housing to be removed without
disconnecting pipe or moving the motor. Provide renewable casing rings
locked against rotation, with one ring mounted in suction inlet assembly
and the other ring mounted in pump assembly. Provide with casing vent and
drain connections. Pump casing shall be back pull out design. Pump
impeller shall be enclosed type, fully machines throughout. Axial balance
shall be obtained by balancing ports and rear sealing rings. Casing and
impeller wear rings shall be of different hardness designed for long
wearing qualities. Pump shaft shall be provided with shaft sleeve designed
to prevent water leakage between shaft and sleeve. Sleeve shall be
anchored to the shaft to prevent any rotation of the sleeve relative to the
shaft. Shaft shall be keyed on the driven end for easy removal of the
coupling half. Shaft shall be completely encased along its entire length
within the wetted area by the impeller and shaft sleeves. Provide adequate
fillets for changes in diameter. Design to limit the maximum shaft
deflection at the stuffing box to 0.05 mm 0.002 inch. Pump bearings shall
consist of two bearing assemblies, tapered-roller type, mounted in an
oil-filled housing. Provide adequate seals to prevent leakage of oil to
outside and dust entry to the inside. Bearings shall have 60,000 hour
minimum B10 life under design head conditions. Bearing loading for thrust
determination shall be at the most adverse operating condition of the pump.
SECTION 15864N
Page 58
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