38
PUMPOUT AND REFRIGERANT
TRANSFER PROCEDURES
Preparation —
For refrigerant side service work the
refrigerant can be isolated in a storage tank. The following pro-
cedures and Fig. 37-38 describe how to transfer refrigerant
from vessel to vessel and perform chiller evacuation.
Fig. 37 — Typical Optional Pumpout System Piping Schematic with Storage Tank
CAUTION
If equipped, the power to the pumpout compressor oil
heater must be on whenever any valve connecting the pum-
pout compressor to the chiller or storage tank is open.
Leaving the heater off will result in oil dilution by refriger-
ant and can lead to compressor failure. Similarly a recovery
unit suited for low pressure refrigerant should be used.
CAUTION
Always run the chiller cooler and condenser water pumps
and always charge or transfer refrigerant as a gas when the
chiller pressure is less than -15 in. Hg (-51 kPa). Below this
pressure, liquid refrigerant flashes into gas, resulting in
extremely low temperatures in the cooler/condenser tubes
and possibly causing tube freeze-up.
WARNING
During transfer of refrigerant into and out of the optional
storage tank, carefully monitor the storage tank level gage.
Do not fill the tank more than 90% of capacity to allow for
refrigerant expansion. Overfilling may result in damage to
the tank or the release of refrigerant which will result in
personal injury or death.
CAUTION
Do not mix refrigerants from chillers that use different
compressor oils and ensure that tanks previously used with
a different refrigerant have been cleaned in order to avoid
refrigerant contamination. Compressor and heat exchanger
damage can result.
CAUTION
Transfer, addition, or removal of refrigerant in spring-
isolated chillers may place severe stress on external piping
if springs have not been blocked in both up and down
directions.
STORAGE
TANK LIQUID
VALVE
OIL
SEPARATOR
PUMPOUT
CONDENSER
WATER SUPPLY
AND RETURN
PUMPOUT
CONDENSER
STORAGE TANK
VAPOR VALVE
2
3
4
5
PRESSURE
RELIEF SAFETY
VALVE
PUMPOUT
COMPRESSOR
REFRIGERANT
CHARGING VALVE
LIQUID LINE
SERVICE
VALVE
CHILLER
CONDENSER
VESSEL
CHILLER
COOLER
VESSEL
10
6
7
11
1a
1b
SERVICE VALVE ON
PUMPOUT UNIT
=
SERVICE VALVE ON
CHILLER (FIELD
SUPPLIED)
=
=
MAINTAIN AT LEAST 2 FT (610mm) CLEARANCE AROUND
STORAGE TANK FOR SERVICE AND OPERATION WORK.
REFRIGERANT
CHARGING VALVE
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