Brochure

Parker Hannifin Corporation
Climate & Industrial Controls Group
Cleveland, OH
Catalog CIC-2003-1/US
160
Thermostatic and Constant Pressure (Automatic) Expansion Valves
Recommended Thermostatic Valve Charges
General Information Thermostatic Expansion Valves
Low Temp -40°F to 0° F
Refrigeration (-40° C to -20° C)
Commercial -40° F to +60° F
Refrigeration (-40°C to +15° C)
Low Temp
Pressure
Limiting
Commercial
Pressure
Limiting
Air +30° F to +60°F VX100
Conditioning (0°C to +15°C) VX100A
Heat Pump -15°F to +60° F
(-30° C to +15°C)
-10°F to +60° F
(-20° C to +15°C)
-40°F to 0° F
(-40° C to -20°C)
Applicable
Evaporator
Temperature Range Application
R-22
R-407C
R-12
R-134a
R-502
R-404A
–
VZ – SZ –
– SX35
SW
R-410A
KX200
KX200
–
VW JW
KX200VX100 JX60 SX110
VX35
VX100 ––
JX60 SX110
evaporator conditions are achieved more rapidly than
the all purpose “W” liquid charge. Additionally, the
“Z” charge prevents the possibility for compressor
floodback on startup due to higher operating super-
heats at higher evaporator temperatures. Like the “W”
charge, the “Z” liquid charged bulb maintains control
even when the valve power element is colder than the
bulb.
Since the “Z” charge is designed specifically for low
temperature applications, it does not exhibit “flat”
superheat control over the entire operating range. This
characteristic decrease in superheat as the evaporator
temperature decreases allows the system to reach the
desired operating conditions quickly. Due to this “slope”
in superheat control (see graph at the right below), it is
possible to optimize the operating superheat for any
particular application by adjusting the valve after operat-
ing conditions are achieved.
The graph at the right illustrates the typical superheat
control characteristics of Parker thermostatic valve bulb
charges.
Parker Thermostatic Bulb Charges
X Charge
The Parker “X” anti-hunt gas cross charge can be used
with evaporator temperatures from -40°F to +60°F
(-40°C to +15°C). Every “X” charge is a pressure
limiting, or MOP (Maximum Operating Pressure), type
charge which limits flow on startup to prevent flooding
and/or compressor overload. The approximate maxi-
mum evaporator operating pressure is designated in
psig by the numbers which follow the “X”, e.g. “X60”
has an approximate pressure limit of 60 psig. Due to
the pressure limiting characteristics of these charges,
each charge is usable over a specific evaporator
temperature range which can be determined by refer-
encing the MOP number and refrigerant type in the
table below.
Valves with an “X” type charge should not be used
where the power element could get colder than the
thermal bulb. Migration of the bulb charge to the power
element can occur causing a loss of valve control. The
only exceptions to this are the R-22 type VX100 charge
and R-410A type KX200 charge, which are non-migrat-
ing charges designed specifically for air-conditioning,
heat pump and medium temperature applications.
Recommended thermostatic valve charges are listed in
the table at the right. A “–” indicates that a charge is
not available for an application.