JOHNSON CONTROLS
69
SECTION 4 - OPERATIONAL MAINTENANCE
FORM 160.67-O2
ISSUE DATE: 10/9/2020
4
Refrigerant Charging
Should it become necessary to add refrigerant charge to
a YORK YST Chiller; add charge until the evaporator
approach and refrigerant gas discharge superheat are
within the temperature values listed in
A charging valve is located in the liquid line below the
evaporator (See
). The size of
the charging connection is 3/4 inch male flare. Purge
air and non-condensables from the charging hose. Only
add new refrigerant, or refrigerant that has been tested
and certified to meet American Refrigeration Institute
Standard (ARI-700).
REFRIGERANT LEAK CHECKING
Periodic refrigerant leak checking must be part of a
comprehensive maintenance program. Leak check the
entire chiller using a calibrated electronic leak detector.
Use a soap solution to confirm leaks that are found us-
ing the electronic leak detector.
Check refrigerant relief valve piping and tube rolled
joints as part of the comprehensive refrigerant leak
checking program.
Repair leaks before adding refrigerant.
PRESSURE CONNECTIONS
All threaded pressure connections used on the YORK
YST Chillers are SAE straight thread, O-ring face seal
type fittings or Primore Rotalock
fittings.
The O-ring straight thread fittings and O-ring face seal
fittings are designed and used in accordance with SAE
J1926 and J1453. Should it become necessary to remove
a fitting, the O-ring(s) should be replaced. Make cer-
tain to use only neoprene replacement O-rings. O-rings
can be ordered from the local Johnson Controls Service
Office.
Pipe sealant compounds are not required with SAE
type O-ring fittings. The O-ring seal accomplishes the
pressure sealing. Lubricate the O-ring with compressor
oil prior to assembly.
All filter driers and angle shut off valves use Primore
Rotalock
fittings. These fittings use a Teflon
fiber
seal washer. The Teflon
fiber seal washers should be
replaced each time the filter driers are changed.
