User's Manual
309024 13
Calculate the Ratio Setting
In this example,
A 5:1 ratio of base to catalyst is required.
The base/primary pump Model (e.g. 221074);
effective area is 0.470 in.
The catalyst/secondary pump Model (e.g. 221026);
effective area is 0.278 in.
1. To determine the base to catalyst setting.
a. Multiply the primary pump’s effective area by
91 (nominal ratio setting).
0.47 primary pump’s effective area
x
91 nominal ratio setting
42.77 answer a
b. Multiply the catalyst pump’s effective area by
the ratio required.
0.278 catalyst pump’s effective area
x 5 ratio required
1.39 answer b
a. Divide answer a by answer b to determine the
index setting.
42.77 answer a
.
/
.
1.39 answer b
30.8 catalyst pump index setting
2. To make sure the index setting does not exceed
the secondary pump’s maximum stroke length:
a. Multiply the index setting by 0.044 (a constant
number).
30.8 catalyst pump setting
x 0.044 constant
1.355 catalyst pump stroke length
a. See the Pump Specifications Chart on page
12 for the pumps’ maximum stroke length. Do
not use an index setting which will exceed the
maximum stroke length for your pump model.
3. To make sure the index setting does not go below
the secondary pump minimum ratio setting, refer
to 309025 Configured Product Order Form. Do not
use a ratio higher than that specified in the maxi-
mum set position, mix ratio column for your sys-
tem.
4. The number (1.355 from step 2.a.) does not
exceed the pump maximum stroke nor does it go
below the minimum ratio setting, so set the cata-
lyst pump at the 30.8 index setting.
NOTE: The ratio index is only a reference point and
ratio checks must be performed to qualify the exact
ratio set desired..