Graco 970086 Instructions-Parts List Manual page 9

Pneumatic Crossover Setup
(Model 970086)
Install the pneumatic crossover as shown in Fig. 3.
Refer also to manual 310293.
During system operation, as the ram approaches the
drum bottom, the top of the ram contacts the limit
valve. The valve shuts off air to the ram air motor via a
4–way piloted air valve. As the valve stops air to one
air motor, it starts air to the other air motor. This allows
constant material flow and changing out of material
drums.
KEY
A 2–Way Valves (2)
B Regulator
C 4–Way Piloted Air Valve
D Limit Valves (2)
E Main Air Inlet
Fig. 3
System Setup
Pneumatic Crossover Setup (Model 970086)
B
C
E
NOTE: Air is supplied to each ram at all times. Air is
only toggled between air motors.
NOTE: The position of the limit valve (D) on the ram
determines when the ram air motor is turned on and
off. During operation, this position can be adjusted as
desired. See Fig. 3.
A
D
8887A
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