passing through tubes and outlet air in shell, designed to reduce
cooling load at design conditions by precooling inlet air minus 7
degrees C 20 degrees F.
b.
Main heat exchanger: Shell and tube construction, single-pass,
with air in tubes and water in shell, designed for minimum air
pressure drop, flanged connections, tubes rolled into tube sheets,
and ASME BPVC SEC VIII D1 and ASME BPVC SEC IX Code stamped.
c.
Separator: Fabricated of carbon steel to ASME BPVC SEC VIII D1and
ASME BPVC SEC IX Code and stamped.
d.
Drain:
With condensate trap.
2.7.2
Chilled Water Circuit
a.
Circulating pump: Single stage, mechanical seals, electric motor
driven with line shut-off valves.
b.
Liquid cooler: Direct expansion, refrigerant in tubes, water in
shell, designed for 2068 kPa (gage) 300 psig working pressure,
removable tube bundle, ASME BPVC SEC VIII D1 and ASME BPVC SEC IX
Code stamped and insulated with foam type insulation.
c.
Expansion tank:
With sight glass, vent, and fill cock.
d.
Flow switch: To shut down refrigeration compressor on loss of
chilled water flow.
2.7.3
Refrigeration System
a.
Refrigeration compressor: ARI 520. Hermetic or semihermetic
reciprocating type, with 183 rad/sec 1750 rpm motor, integral
capacity control, oil pressure pump, oil scavenger pump, full-flow
oil filter, oil sight glass, inherent motor protection, crankcase
heater, suction and discharge service valve, crankcase oil
strainer, Monel suction screen, and hot gas bypass capacity
control below last step of unloading. Refrigerant shall be R-22.
b.
Accessories: Include a discharge line muffler, sight glass,
refrigerant dryer, solenoid valve, thermostatic expansion valve,
and suction line strainer.
c.
Air-cooled condenser: As indicated. Complete air-cooled
condenser factory-fabricated and assembled unit consisting of
coils, fans, and electric-motor drive. Base capacity at design
conditions on minus 7 degrees C 20 degrees F temperature
differential between entering air and condensing refrigerant.
Saturated refrigerant condensing temperature not over 40 degrees C
105 degrees F. Base entering dry bulb outside air temperature on
[32] [_____] degrees C [90] [_____] degrees F. Do not take
subcooling into account in determining compressor and condenser
capacities. Air-cooled condenser may be used for refrigerant
storage in lieu of a separate receiver, provided that condenser
storage capacity is 20 percent in excess of fully charged system.
[Provide head pressure control during low ambient temperature.]
SECTION 15212N
Page 25
Previous Page
