Ratio Adjustment; Terms - Graco Hydra-Cat H.P. Series Instructions Manual

Understanding the terms used with the Hydra–Cat (H.P.)
System, how it functions, and how to find and set the
correct ratios for your application is the key to easier, more
versatile operation of your proportional system.
Be sure to read and understand the following information
before operating the equipment.

Terms

Ratio refers to the simultaneous output of a certain volume
of fluid by the primary and secondary pumps.
Key
A Primary Pump
B Secondary Pump
C Ratio Adjustment Screw
Fig. 4

Ratio Adjustment

The primary pump (A) is directly under the air motor (H);
it usually pumps the base fluid. The secondary pump (B)
is on the opposite end of the lever arm (E); it usually
pumps the catalyst. The ratio of the secondary pump(s)
can be changed by adjusting the ratio adjustment screw
(C). See Fig. 4.
There are three main steps when applying the use of ratios:
(1) determine the ratio that is required, (2) calculate the
ratio setting, and (3) set the ratio on the Hydra-Cat H.P.
system.
D Wet Cups
E Fulcrum and Arm
F Primary Pump Output
G Secondary Pump Output
H Air Motor
I Air Input
J Bleed Type Master Air Valve
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