50
YORK INTERNATIONAL
SECTION 7
MAINTENANCE
RENEWAL PARTS
For any required Renewal Parts, refer to Parts Lists
shown in Reference Instructions, 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 has been charged, the system should
be carefully leak tested with a R-134a compatible leak
detector to be sure all joints are tight.
If any leaks are indicated, they must be repaired im-
mediately. Usually, leaks can be stopped by tightening
flare nuts or flange bolts. However, for any major re-
pair, the refrigerant charge must be removed. (See
Handling Refrigerant for Dismantling and Repair, page
54.)
CONDUCTING R-22 PRESSURE TEST
With the R-134a 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 ha-
lide torch or electronic leak detector can be used to
detect any leaks too small to be found by the soap test.
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 25 to 50 psig (172 to 344 kPa). To
be sure that the concentration of refrigerant has
reached all part of the system, slightly open the oil
charging valve and test for the presence of refriger-
ant with a leak detector.
3. Test around each joint and factory weld. It is impor-
tant that this test be 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.
EVACUATION AND DEHYDRATION OF UNIT
FIG. 21
EVACUATION OF CHILLER
27385A(D)
LD00949
