15
The oil cooler does offer some help in keeping
the discharge and motor temperatures within
their respective limits. To make up for this lost
cooling some additional refrigerant injection is
required. For screw compressors this injection
is by the motor cooling valve or at the rotor
injection port. Because refrigerant injection for
motor and discharge cooling flows into the
screw rotor chamber after the suction gas is
trapped, compressor capacity is not affected
significantly. Under some conditions the motor
cooling valve can accommodate this extra
cooling requirement. For conditions requiring
additional injection, a Sporlan Y-1037 desuper-
heating valve, or its equivalent, is recommend-
ed. It should be selected to start opening at a
discharge temperature of 190 F and be fully
open at 200 F. The bulb should be located on
the discharge line within 6" of the compressor
discharge service valve. A properly sized sole-
noid valve should be located upstream to
insure positive shut-off when the compressor is
off.
The tables presented at the bottom of this
page present desuperheating size and part
number information for those applications
where an oil cooler is not used.
Even when an oil cooler is used, desuperheat-
ing may still be required. For R-22 systems,
the desuperheating valve is required when
the saturated suction temperature is below
-25°F (-32°C) and for R-404A/R-507 systems,
it is necessary when the saturated suction
temperature is below -40°F (-32°C). This valve
is available through Carlyle (1 ton (3.5Kw);
1.5 ton (5.3Kw); contact Carlyle Application
Engineering for valve selection).
DESUPERHEATING VALVE SIZING WITHOUT OIL COOLER
R-22 Added Desuperheating R-404A/507 Added Desuperheating R134a Added Desuperheating
Compressor
Model
HP
Low Temp. Med/High Temp. Low Temp. Medium Temp. Medium Temp. High Temp.
Low Temp.
SCT Range 70 to 120 F 90 to 120 F 70 to 150 F 70 to 150 F
(21 to 49 C) (32 to 49 C) (21 to 65 C) (21 to 65 C)
06TRC033 15 FV-2 N/A FV-1* N/A None None
06TRD039 20 FV-3 N/A FV-1-1/2* N/A None None
06TRD044 20 FV-3 N/A FV-1-1/2* N/A None None
06TRE048 25 FV-3 N/A FV-2* N/A None None
06TRE054 25 FV-3 N/A FV-3* N/A None None
06TRF065 30 FV-5 N/A FV-3* N/A None None
06TRG078 35 FV-5 N/A FV-3* N/A None None
06TRH088 40 FV-5 N/A FV-3* N/A None None
06TRK108 50 FV-5 N/A FV-3* N/A None None
Med Temp/High Temp
SCT Range 70 to 130 F 70 to 130 F
(21 to 54 C) (21 to 34 C)
06TAD033 20 N/A FV-2** N/A None None None
06TAE039 25 N/A FV-3** N/A None None None
06TAF044 30 N/A FV-3** N/A None None None
06TAF048 30 N/A FV-3** N/A None None None
06TAG054 35 N/A FV-3** N/A None None None
06TAG065 35 N/A FV-5** N/A None None None
06TAH078 40 N/A FV-5** N/A None None None
06TAK088 50 N/A FV-5** N/A None None None
LEGEND
* Operation with Evap condensers below -25 F SST may not require any additional desuperheating.
Contact Carlyle Applicatioon Engineering for limits.
** Operation with Evap condensers above +10F SST may not require any additional desuperheating.
Contact Carlyle Application Engineering for limits.
Note: Valve P/N's shown above are for Sportan Valve Y-1037 series desuperheating valves. A valve with a 190 F temperature setting is required. Alternate
desuperheating valve sizing or manufacturers must be approved by Carlyle Application Engineering.
Sporlan Part No. Carlyle Part No. Qty./Pkg. Weight (Lbs.) Size
FV-1 EA02ZD001 1 2 1 ton
FV-1-1/2 EA02ZD002 1 2 1-1/2 ton
FV-2 EA02ZD030 1 2 2 ton
FV-3 EA02ZD050 1 2 3 ton
FV-5 EA02ZD100 1 2 5 ton