User's Manual

12 309024
Set the Ratio
Fig. 5 shows the relationship between the primary
pump and the secondary pump.
To set the secondary pump on a standard VRHC
System with only two pumps, refer to Setting the
Secondary Pump(s) on page 14.
To set the secondary pump on a non-standard VRHC
System or for an additional secondary pump, refer to
Calculate the Ratio Setting, on page 13.
NOTE: The (91) index setting provides equal primary
and secondary pump stroke lengths. 100 is 1.1 times
the primary pump stroke, allowing adjustability on both
sides of the nominal ratio setting of 91. If the same
primary and secondary pump models are used, a 91
setting will give a 1:1 ratio. If different pump models
are used, you must know the pump’s effective area to
determine the setting. The displacement pumps effec-
tive areas are listed in Configurator Product Order
Form 309025
1
2
123
1
2
3
124
20%
91%
100%
HH
3 3
118
Primary Stroke –
4” (102 mm)
Secondary Stroke
Effective Area
KEY
HH Lever Arm Index
4
4
4
4
Index Setting
02368
Fig. 5
Relationship Between Primary and
Secondary Pump
Moving the secondary pump closer to the primary
pump (to a lower index setting) reduces the secondary
stroke length, reducing its fluid output. Moving the
secondary pump further from the priming pump (to a
higher index setting) increases the secondary stroke
length, which increases its fluid output.