SpectraPure
®
SpectraPure
®
Inc.
480.894.5437 Call us toll-free 1.800.685.2783
2167 East Fifth St, Tempe, Arizona 85281
13
REVERSE OSMOSIS MEMBRANE PRODUCTION RATE TESTING:
Actual production rate of a membrane is dependent on two factors: Tap Water Pressure and Tap Water Temperature.*
The testing standards for RO membranes are 60 psi (4.1 bar) tap water pressure and 77
°
F (25
°
C) tap water temperature.
Changing either of these factors affects the output of the RO membranes.
PRESSURE COMPENSATION:
The Pressure Compensation Factor is calculated by dividing the water pressure at the inlet for the RO membrane by the
standardized 60 psi rating that is used for all membranes. Since the 200UHE comes factory equipped with a brushless DC
booster pump, that figure should always be 80/60 or 1.33 (4/3). (See Pressure Adjustment on page 8.)
The UHE System uses two RO Membrane that are each nominally rated to produce 90 GPD at 60 psi. Therefore, the
expected production (before Temperature Compensation) would be 180 x 4/3 or 240 GPD.
TEMPERATURE COMPENSATION:
The viscosity of water changes with temperature. Colder water does not pass through the membrane as easily as warm
water. Look up the water temperature on the chart below to determine the Temperature Compensation Factor (TCF)
value. Multipy it by the pressure-compensated flow rate of 240 GPD.
For Example, if your tap water temperature is 59° F. The TCF is 0.730.
Multiplying 240 GPD by 0.730 results in a temperature-compensated flow rate of 175.2 GPD.
Temperature Correction Factor Table (TCF)
°F /°C
TCF
°F /°C
TCF
°F /°C
TCF
41.0 /5
0.521
59.0 /15
0.730
77.0 /25
1.000
42.8 /6
0.540
60.8 /16
0.754
78.8 /26
1.031
44.6 /7
0.560
62.6 /17
0.779
80.6 /27
1.063
46.4 /8
0.578
64.4 /18
0.804
82.4 /28
1.094
48.2 /9
0.598
66.2 /19
0.830
84.2 /29
1.127
50.0 /10
0.620
68.0 /20
0.857
86.0 /30
1.161
51.8 /11
0.640
69.8 /21
0.884
87.8 /31
1.196
53.6 /12
0.661
71.6 /22
0.912
89.6 /32
1.232
55.4 /13
0.684
73.4 /23
0.941
91.4 /33
1.267
57.2/14
0.707
75.2 /24
0.970
93.2 /34
1.304
* Tap Water Hardness is also a factor that, at high levels, will reduce the production rate. For simplicity, that factor has
not been accounted for in this equation as its effect is not nearly as pronounced as that of temperature and pressure.
