shall be standard Class 150 ANSI flat-faced flanges, rubber lined, if pump
is rubber lined. Furnish drawings and data as specified in paragraph
entitled "Submittals." Include in submittals information for the general
arrangement and outline, instrumentation, piping connection, electric
motors sound pressure ratings, description of flushing system for slurry
pumps, and performance curves.
2.10.1.1
Centrifugal Pumps
Pump speed shall be such that the upper limits of specific speed, as
defined by the applicable figure of the HI SCRRP are not exceeded at any
pump operating condition. Total dynamic head of pumps shall be maximum at
zero flow and continuously decreasing from zero flow to design flow. Head
capacity characteristics shall permit stable operation when pump is
operating alone or in parallel with other pumps of the same designation.
Pump shut-off head shall be more than 110 percent of design point head and
less than 150 percent of design point head. Pump shaft critical speeds
shall not occur from 10 percent of design point head. Pump shaft critical
speeds shall not occur from 10 percent to 120 percent of design rpm. Pump
shaft shall be free from excessive vibration at discharge rates from 10
percent to 120 percent of design delivery. Impeller shall not be maximum
or minimum size for pump casing furnished to allow for possible future
modification of head capacity furnished to allow for possible future
modification of head capacity characteristic by changing impeller size. The
maximum allowable sound pressure level shall be 84 dB for each pump-motor
unit. Slurry pumps shall be vertically split-case, rubber-lined
single-stage pumps designed for indoor service. Water pumps shall be
vertically split-case single-stage pumps designed for outdoor service.
Slurry pumps shall be provided with shaft seals which do not require water
flushing. Provide water pumps with mechanical shaft seals which do not
require an external source of seal water. Pumps shall be provided with
flexible inlet and outlet connections.
2.10.1.2
Vertically Split-Case Rubber-Lined Pumps
Vertically split-case rubber-lined pumps shall be end suction,
single-stage, single-suction centrifugal, of the volute type. Pump trim
shall be stainless steel suitable for the service and designed for
continuous operation at specified operating conditions. Pumps shall be
frame mounted with pump shaft carried on its own bearings with multiple
V-belt drive between pump and motor. Pumps shall have bottom horizontal
discharge. Pump casing shall be split vertically into suction inlet
assembly and pump assembly designed for ease of disassembly. Casing shall
have replaceable secured rubber liner, minimum 10 mm 3/8 inchthick designed
for long life under operating conditions specified. Pump impeller shall be
enclosed type, of soft natural rubber on steel skeleton. Pump shaft shall
be provided with ceramic faced shaft sleeves designed to prevent water
leakage between shaft and sleeve. Sleeve shall be adequately 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. Pump bearings shall consist of two bearing
assemblies, ball or tapered type roller type, mounted in an oil-filled or
grease-lubricated housing. Provide adequate seals to prevent leakage of
lubricant to outside and dust entry to inside of housing. Bearings shall
have 60,000-hour minimum B-10 life under design conditions in accordance
with ABMA 9 and ABMA 11. Design to limit maximum shaft deflection to 0.05
mm 0.002 inch. Provide with lubrication system consisting of a
SECTION 15864N
Page 57
Previous Page
