SANY SY155U, Operation And Maintenance Manual, Page: 48 / 192

3-18
MACHINE CONTROLS
SY155U Excavator OMM
Return Flow Selector Valve
0004523
Figure 3-31 One-way Flow
0004522
Figure 3-32 Two-way Flow
The return flow selector valve (1) has a one-way or
two-way position for operating optional attachments. It is
on the left side of the hydraulic oil tank.
Set the valve by turning the valve knob (4) clockwise or
counterclockwise until the stops (2) on the knob contact
the stop pin (3):
• Turn the valve clockwise until the stop is reached
for one-way flow.
• Turn the valve counterclockwise until the stop is
reached for two-way flow.
A variety of optional one-way and two-way flow
attachments are available for use on this machine. A
breaker is an example of a one-way flow attachment, and
a shear is an example of a two-way flow attachment.
Directional Arrow
0003664
Figure 3-33
The directional arrow (1) on the inside of each track
frame indicates the forward direction of the
undercarriage. Check these arrows before using the
travel control levers. When possible, face the cab in this
direction.
NOTE: When the operator cab faces backward, the travel
direction will be the reverse of the normal travel
control functions. (The machine moves forward
when you pull the control levers backward, and
the machine moves backward when you push the
control levers forward.)
NOTE: The right side directional arrow is shown. The left
side is similar.
Stop Valve
0003570
Figure 3-34
Two stop valves (1) are mounted on the arm to aid in the
removal and installation of optional equipment by
shutting off hydraulic flow when optional equipment is
removed. See “Install Optional Equipment” on page 7-3.
NOTE: The right side of the arm stop valve is shown. The
left side is similar.
The stop valve is shown in the closed position. To open
the valve, turn the valve knob (2) counterclockwise until
the stop (4) makes contact with the stop pin (3).
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