SpectraPure
®
SpectraPure
®
Inc.
480.894.5437 Call us toll-free 1.800.685.2783
2167 East Fifth St, Tempe, Arizona 85281
16
MEMBRANE PRODUCTION CALCULATION:
Membranes produce the rated gallons per day (GPD) at 60 psi (4.1 bars)
operating pressure, 77°F (25°C) operating temperature and with no more
than 250 ppm total dissolved solids.
Membrane output gallons per day (GPD) depends on operating pressure,
water temperature and the TDS in the feed water.
Expected GPD = Rated GPD × PCF × TCF
PCF
is the pressure correction factor
TCF
is the temperature correction factor
Calculation of Pressure Correction Factor (PCF):
The output (GPD) from
the membrane is directly proportional to the applied pressure.
NOTE: The membrane is rated to produce the rated GPD at 60 psi. For any
pressure other than 60 psi the output GPD is multiplied by the PCF.
PCF = Line Pressure (in psi) ÷ 60
Calculation of Temperature Correction Factor (TCF):
The output (GPD)
decreases with a decrease in temperature. This is due to water viscosity
increasing with a decrease in water temperature.
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
(continued on next page)
