7037/7038/7040/7041
User's Guide
18
1. The back pressure valve adjustment is used to control the amount of
cooling supplied to the system. This valve reduces the cooling capacity by
restricting the flow of refrigerant to the bath, allowing the adjustment of
the heating to cooling percentage. Under normal operation the valve
should be fully open (counter clockwise).
2. The cooling temperature regulating valve is used to adjust the
temperature at which the refrigerant evaporates, which determines
cooling efficiency. Refer to the label below the gauge for approximate psi
and evaporative temperature settings. The following table is reproduced
from the label.
For this bath: Control Temperature
Set the Cooling Temp. Valve to this
pressure
°C
°F
Nominal Cooling PSIG
–40
–40
0 to 3
–35 –31 3
–30 –22 5
25 –13 9
–20 –4 15
–15 5 22
–10 14 29
–5 23 38
0 32
48
5 41
60
10 50 72
15 59 87
20 68 90
25 77 90
30 86 90
35 95 90
DO NOT set the Cooling Pressure above 90 PSIG
3. The cooling temp gauge is used to indicate the pressure at which the
evaporating temperature is adequate. the cooling temp regulating valve is
used to adjust and then control this temperature. Interpolate for
temperatures in between those shown.
