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A feeder unit shall be provided for each boiler. Chemical feeders shall be
automatic proportioning, shot, or pump type. All appurtenances necessary
for satisfactory operation shall be provided. Size and capacity of feeder
shall be based upon local requirements and water analysis. Feed piping
shall be installed to feed chemicals directly to each boiler, as shown on
the drawings or as required for the equipment supplied.
2.8.2
Pumps and Tanks
Chemical feed pumps and tanks shall be furnished as a package with the
pumps mounted on and piping connected to the tank. Pump cylinders,
plungers, ball check valves, and check valve bodies shall be of
corrosion-resistant materials suitable for the chemicals being pumped.
Volumetric accuracy of the pumps shall be within one percent over the range
indicated. Pump capacities shall be adjustable by positioning the crankpin
with micrometer setscrews. Stroke length scale shall be divided in
percentage graduations engraved on the scale. Cylinders shall be
replaceable for increased or reduced pressure or capacity ranges. Drive
motors shall be suitable for the electric power available and shall have
drip-proof enclosures. Each pump shall be driven by a separate motor.
Tanks shall be made of polypropylene and mounted on legs. Tanks shall have
filling and drain connections, and gauge glass. Each tank shall be
furnished with one pump, mounted and piped with black iron pipe and
fittings, with suction strainer and stainless steel screen, and with 13 mm
1/2 inch relief valve with steel body and stainless steel trim. Each tank
shall have a hinged cover. Tank bottom shall be dished concave to a radius
equal to the diameter of the tank. Units shall be for phosphate or caustic
feed and sulfate feeding. Motor-driven agitator shall be provided. The
pump shall be designed to feed the chemical solutions into the boiler
feedwater system.
2.8.3
Water Softening Equipment
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NOTE: Need for softening equipment for makeup water
will be as determined in accordance with TM 5-810-1.
If water softening is not required, delete the
paragraph.
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A complete sodium zeolite cycle water softening system shall be provided as
specified in Section 11250 WATER SOFTENERS, CATION-EXCHANGE (SODIUM CYCLE).
Equipment shall be sized to run 24 hours before regeneration when
operating at a sustained softening rate of [_____] L/second gpm. Tanks
shall be complete with cover and designed to eliminate the need for a
gravel supporting bed.
2.9
BOILER CONTROL EQUIPMENT
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NOTE: Positioning type control equipment will be
specified for boilers with capacities of 13 MW (45
MBtuh) or less. Metering type equipment will be
used for larger boilers. Positioning type controls
may be furnished for boilers with capacity of 13 MW
(45 MBtuh) or more in lieu of metering type.
SECTION 15846A
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