orifice.
(1) System Bypass Flow Controller: Include detection of low flow
and modulation of a control valve in a bypass line returning to a
low pressure sink. Incorporate a pressure let-down feature or
device to reduce the pressure from the boiler feedwater pump
discharge pressure to that of the low pressure sink.
(2) System Bypass Control Valve: Modulate to provide minimum
flow recommended by the pump manufacturer and to provide shutoff
or recirculation flow when feedwater flow to the boilers exceeds
the minimum flow required for pump protection.
c.
Feedwater Stop and Check Valves: Provide a Class 300, flanged,
cast steel feedwater stop gate valve and check valve on the
feedwater outlet of each pump. Provide piping from the valves to
the economizer inlet, and from the economizer to the flanged
connection on the boiler drum. Provide connection on pipe at
economizer outlet for remote recording thermometer.
2.9.4
Condensate Pumps
**************************************************************************
NOTE: Use this paragraph for centrifugal condensate
pumps. Pump service requirements shall include pump
capacity a minimum of 125 percent of boiler
requirements. Discharge into deaerator heater shall
be modulated.
**************************************************************************
FS A-A-50562, Type I, Style [1 (horizontally split case)] [2 (end
suction)], Class 1 (single stage) unless modified below.
2.9.4.1
Condensate Pump Service Requirements
a.
Capacity:
[_____] L/s gpm
b.
Pumping temperature range:
[_____] to [_____] degrees C F
c.
Liquid pH:
[_____]
d.
Discharge head:
[_____] Pa feet
e.
Available NPSH:
[_____] Pa feet
f.
In addition to the operating point established above, the pump
curve shall also run through the following points:
Capacity
Discharge Head
[_____] L/s
[_____] Pa
[_____] L/s
[_____] Pa
Capacity
Discharge Head
[_____] gpm
[_____] feet
[_____] gpm
[_____] feet
SECTION 15511N
Page 57
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