Specifications

52 YORK INTERNATIONAL
SECTION 7
MAINTENANCE
RENEWAL PARTS
For any required Renewal Parts refer to Forms listed on page 2.
CHECKING SYSTEM FOR LEAKS
LEAK TESTING DURING OPERATION
The refrigerant side of the system is carefully pressure
tested and evacuated at the factory.
After the system is in operation under load, the high
pressure components should be carefully leak tested
with a leak detector to be sure all joints are tight. If a
leak exists frequent purging will be required or refriger-
ant will be lost.
If any leaks are indicated, they must be repaired imme-
diately. Usually, leaks can be stopped by tightening flare
nuts or flange bolts. However, if it is necessary to repair
a welded joint, the refrigerant charge must be removed
(See “Handling Refrigerant for Dismantling and Repairs”,
page 55).
CONDUCTING PRESSURE TEST
With the refrigerant charge removed and all known leaks
repaired, the system should be charged with a small
amount of R-22 mixed with dry nitrogen so that a halide
torch or electronic leak detector can be used to detect
any leaks too small to be tound by the soap test. Do not
use excessive amounts of R-22; use only enough for
proper leak detection.
To test with R-22, proceed as follows:
1. With no pressure in the system, charge R-22 gas
into the system through the charging valve to a pres-
sure of 2 PSIG.
2. Build up the system pressure with dry nitrogen to
approximately 10 PSIG. To be sure that the concen-
tration of refrigerant has reached all parts of the sys-
tem, slightly open the oil charging valve and test tor
the presence of refrigerant with a leak detector.
3. Test around each joint and factory weld. It is impor-
tant that this test by thoroughly and carefully done,
spending as much time as necessary and using a
good leak detector.
4. To check for refrigerant leaks in the cooler and con-
denser, open the vents in the cooler and condenser
heads and test for the presence of refrigerant. If no
refrigerant is present, the tubes and tube sheets may
be considered tight. If refrigerant is detected at the
vents, the heads must be removed, the leak located
(by means of soap test or leak detector) and repaired.
5. When absolute tightness of the system has been
established, blow the mixture of nitrogen and refrig-
erant through the charging valve.
VACUUM TESTING
After the pressure test has been completed the vacuum
test should be conducted as follows:
1. Connect a high capacity vacuum pump, with indica-
tor, to the system charging valve as shown in Fig. 28
and start the pump (see “Vacuum Dehydration”).
2. Open wide all system valves, including the purge
and gauge valves. Be sure all valves to the atmo-
sphere are closed.
3. Operate the vacuum pump in accordance with
“Vacuum Dehydration” until a wet bulb temperature
of +32°F or a pressure of 5mm Hg. is reached. See
Table 3 for corresponding values of pressure.
4. To improve evacuation circulate hot water (not to
exceed 125°F) through the cooler and condenser
tubes to thoroughly dehydrate the shells. If a source
of hot water is not readily available, a portable water
heater should be employed. DO NOT USE STEAM.
A suggested method is to connect a hose between
EVACUATION AND DEHYDRATION OF UNIT