VIII for the specified boiler operating pressure. Automatic proportioning
valve shall be provided with a sensing orifice on both the makeup and
blowdown lines and shall be of the adjustable ratio type in which the ratio
of makeup to blowdown may be set anywhere within a range of [30:1] [_____]
to [4:1] [_____]. Automatic proportioning control shall consist of two
concentric tubes, the inner tube being of a thermostatic design which acts
directly against an adjustable seat in response to the temperature
differential between the blowdown in the inner tube and the makeup water
between the inner and outer tubes. [Manual apportioning valves shall have
bronze bodies with stainless steel seats and disks and shall be of the
indicating type specifically designed for blowoff service.] Blowdown system
shall be complete with strainers, stop valves, [blowdown meters,]
thermometers, and other accessories necessary to form complete packaged
units. [Blowdown control console shall include illuminated sight flow
indicators, automatic flushing and cooling valves, and complete panelboard
instrumentation as well as a cabinet type laboratory sink with drain board,
back splash, hot and cold service water faucets, [air cock,] and electrical
outlets.]
2.4
FEEDWATER EQUIPMENT
2.4.1
Boiler Feed Pumps
Conform to MIL-P-17552 for motor driven, horizontal split case or support
head boiler feed pumps except as otherwise specified herein. Pumps may be
of either the centrifugal or peripheral-turbine type with [cast iron] [or]
[alloy steel] casing and shall be [bronze] [or] [alloy steel] fitted. For
turbine type pumps, provide pressure relief valves and for centrifugal type
pumps, provide by-pass orifice. Packed stuffing boxes or mechanical seals
suitable for the design conditions indicated shall be provided. Pumps
shall be designed for the net positive suction head, discharge head, and
water temperature indicated. [Capacity under the above condition shall be
not less than indicated.] [Capacity of each pump under the above
conditions shall be not less than the following percentage of maximum total
boiler capacity: Centrifugal pumps 125 percent; Turbine pumps 150
percent.] Pump motors shall be [totally enclosed] [dripproof] [dripproof
with encapsulated windings].
2.4.2
Boiler Feed Tank
Feed tank and stand construction shall conform to MIL-P-17749 for
horizontal, cylindrical, stand-mounted receivers and shall be [hot dip
galvanized or cement lined] [epoxy coated] [coated]. Provide tanks with
vents, gage glass, drain and overflow connections, pressure gage,
thermometer, [float operated makeup water feeder] [float switch and makeup
water solenoid valve] [and preheater assembly consisting of corrosion
resistant steam diffuser tube, steam corrosion resistant steam diffuser
tube, steam pressure reducing valve, strainer, and thermostatic steam
valve]. Boiler feed tank assembly shall include boiler feed pumps as
herein specified, interconnecting piping including strainer and pump
control box. Tank capacity and connection sizes shall be as indicated.
2.4.3
Deaerator
Provide pressurized packaged type conforming to MIL-H-17660, be constructed
and stamped in accordance with ASME BPVC SEC VIII D1, 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
SECTION 15516N
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