Refrigerant Charging; Saturation Curve - York CodePak YK L1 L1 G4 Operation Manual

Centrifugal liquid chillers styles a & b with microcomputer control center part 371-01200-004 for electro-mechanical starter & solid state starter

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Table of Contents

FIG. 22 – SATURATION CURVE

medium for carrying this residual moisture to the

vacuum pump, nitrogen should be introduced into the

system to bring it to atmospheric pressure and the

indicator temperature will return to approximately am-

To avoid the possibility if freezing liquid within the cooler

tubes when charging an evacuated system, only re-

frigerant vapor from the top of the drum or cylinder

must be admitted to the system pressure until the sys-

tem pressure is raised above the point corresponding

to the freezing point of the cooler liquid. For water, the

pressure corresponding to the freezing point is 57.5

PSIG (396.5 kPa) for R-22 or 8.54 PSIG (58.9 kPa) for

R-134a (at sea level).

While charging, every precaution must be taken to pre-

vent moisture laden air from entering the system. Make

up a suitable charging connection from new copper

tubing to fit between the system charging valve and

the fitting on the charging drum. This connection should

be as short as possible but long enough to permit suf-

ficient flexibility for changing drums. The charging con-

nection should be purged each time a full container of

refrigerant is connected and changing containers should

be done as quickly as possible to minimize the loss of

refrigerant.

Refrigerant may be furnished in drums containing ei-

ther 30, 50, 125 or 1750 lbs. (13.6, 22.7, 56.7 or 793.8

kg) of refrigerant. These drums are not returnable and

they should be stored for future use if it should ever

become necessary to remove refrigeration from the

system.

YORK INTERNATIONAL

bient temperature. Close off the system again, and start

the second evacuation.

The relatively small amount of moisture left will be car-

ried out through the vacuum pump and the tempera-

ture or pressure shown by the indicator should drop

uniformly until it reaches a temperature of 35°F (1.7°C)

or a pressure of 5 mm Hg.

When the vacuum indicator registers this temperature

or pressure, it is a positive sign that the system is

evacuated and dehydrated to the recommended limit.

If this level cannot be reached, it is evident that there

is a leak somewhere in the system. Any leaks must be

corrected before the indicator can be pulled down to

LD01084

35°F (1.7°C) or 5 mm Hg. in the primary evacuation.

During the primary pulldown, keep a careful watch on

the wet bulb indicator temperature, and do not let it fall

below 35°F (1.7°C). If the temperature is allowed to fall

to 32°F (0°C), the water in the test tube will freeze,

and the result will be a faulty temperature reading.