2.11.3
Deaerator
The deaerator shall be of the pressurized type having an ASME stamped
pressure vessel and conforming to MIL-H-17660 and requirements specified
herein. Deaerating assembly and deaerated water storage may be in the same
or separate shells. When external vent condensers are provided, they may
be located as recommended by the manufacturer. Provide an ASME certified
pressure relief valve sized [as indicated][in accordance with Table II of
MIL-H-17660]. Inlet piping and accessories shall be as indicated.
Feedwater pumps, as specified herein, interconnecting piping, and control
box shall be provided as part of the deaerator package. Deaerator capacity
shall be not less than [indicated] [1.25 times that required to supply the
boiler(s) at maximum firing rate]. The temperature of the water delivered
at maximum capacity shall be equivalent to saturated steam temperature at
the operating pressure of the deaerator, which shall be as indicated, and
the oxygen content shall not exceed [0.005] [0.003] cubic centimeters per
liter as determined by the Referee Method A (Colorimetric Indigo Carmine)
of ASTM D 888 without O2 scavenging chemical addition. Water storage
capacity shall be sufficient to operate the boilers at maximum capacity for
[10] [_____] minutes. A power and control panel shall be furnished with
the package deaerator unit. The panel enclosure shall be NEMA ICS 6, Type
12 and shall be fabricated and painted in accordance with the
manufacturer's standard practice. A separate compartment shall be
furnished for each feedwater pump and each shall include a fused disconnect
switch with external operating handle and a magnetic starter with three-leg
overload protection. The panel shall include signal lights, an audible
alarm to signal high and low levels in the deaerator, and required relays,
transformers, and manual-automatic switches.
2.11.4
Surge Tank and Transfer System
The condensate storage and surge tank shall be a cylindrical welded steel
tank mounted and supported as indicated. Design and construct the tank in
accordance with the ASME BPVC SEC for the indicated working pressure.
Storage capacity shall be [as indicated] [sufficient to provide adequate
water to the deaerator for [10] [_____] minutes of [boiler] [plant]
operation at maximum capacity]. Inlet connections for condensate and
make-up water shall be as indicated. Equip the tank with liquid level
controllers and valves and alarms as indicated. Equip tank with pressure
and temperature gages, water level gage, vent, drain, and overflow. Tank
shall be [hot dip galvanized or cement lined] [epoxy coated] [[_____]
coated]. The surge tank assembly shall include condensate transfer pumps,
interconnecting piping including strainer, and control box as indicated.
The transfer pumps, except for head and temperature requirements which
shall be as indicated, shall operate continuously with a float controlled
flow and shall conform to the requirements for boiler feed pumps specified
herein.
2.11.5
Feedwater Treatment Equipment
2.11.5.1
Feedwater Characteristics
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NOTE: Insert source of water supply.
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Equipment for the chemical treatment of the boiler make-up feedwater shall
be designed to reduce the boiler water concentrations to the limits
specified herein when handling raw water having the following impurities
SECTION 15517N
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