Ross Controls 2_2 WAY WITH PRESSURE RELEASE SERIES 27 - Manual (Page 4)

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V1 V2
3-Position, Open-
Center Control Valve
Cylinder
L-O-X®
Valve
P
Holding
Pressure
Sol C
Flow
Control
Valves
Dual Check
Valve with
Solenoid Pilot
and Relief
Function
C1 C2
Sol A Sol B
TYPICAL APPLICATIONS: Overhead lifter circuits; applications where there is
a long distance between the check valve and the operating valve.
CIRCUIT FEATURES:
• To operate cylinder, simultaneously energize solenoids A and C or B and C.
• Pilot supply and exhaust are independent of control valve. Response time is not affected
by exhaust restrictions of the control valve.
• Cylinder remains stationary if neither control valve solenoid is energized, or if electrical
signal is lost.
• Pressure in cylinder is exhausted when the air supply at “P” port is lost or locked-out.
• L-O-X
® valve provides lockable shutoff of air supply, and exhausting of trapped
downstream air.
IMPORTANT NOTES and CAUTIONS:
» Cylinder movement may occur when inlet pressure is lost. Its movement is slowed
only by the restrictions of the flow control valves, and by the exhaust capacity of the
check valve relief flow capacity.
» The solenoid of the check valve must be wired so that it is energized whenever either
control valve solenoid is energized.
» Pressurizing the system after supply air has been off may cause rapid movement
of the cylinder because cylinder air was exhausted while the supply air was off. See
below for soft-startup circuit.
Dual Solenoid Controlled PO Check Valve Application
Dual PO Check Valve Applications with EEZ-ON ® Valve for Soft Startup
With 2-Position Control Valve
V1 V2
2-Position
Control Valve
Cylinder
L-O-X®
Valve
P
Holding
Pressure
Flow
Control
Valves
Dual Check
Valve with
Solenoid Pilot
C1 C2
EEZ-ON®
Valve
Sol C
Sol A Sol B
With 3-Position Control Valve
V1 V2
3-Position
Open Center
Control Valve
Cylinder
L-O-X®
Valve
P
Holding
Pressure
Flow
Control
Valves
Dual Check
Valve with
Solenoid Pilot
and Relief
Function
C1 C2
EEZ-ON®
Valve
Sol C
External
Pilot
Supply
Sol A Sol B
TYPICAL APPLICATIONS:
Shuttle and lifter circuits; applications where there is a long distance
between the check valve and the operating valve; applications where
gradual cylinder movement upon pressurization is acceptable.
CIRCUIT FEATURES:
• Cylinder will remain fully extended or retracted if electrical
signal to control valve solenoid is lost.
• Pressure in the cylinder is exhausted when the air supply at
“P” port is lost or locked out.
• When the air supply is turned on, the EEZ-ON ® valve
(see page 6) allows slow pressurization of the system so
that the cylinder moves slowly into the fully extended or
retracted position.
• L-O-X ® valve provides lockable shutoff of air supply, and
exhausting of trapped downstream air.
IMPORTANT NOTES and CAUTIONS:
» For cylinder to move, energizing of solenoids A and C or B and
C must occur simultaneously.
TYPICAL APPLICATIONS:
Shuttle and lifter circuits; applications where cylinder movement
upon pressurization is NOT acceptable.
CIRCUIT FEATURES:
• Regulators are set to compensate for differing areas on either
side of cylinder piston. Provides a steady startup and a gradual
stopping of the cylinder.
• When the air supply is turned on, the EEZ-ON ® valve (see
page 6) allows pressure to build up on both sides of the piston.
This minimizes startup “bounce.”
• Pilot operated check valve prevents drifting, and can be close-
coupled to cylinder to reduce “bounce.”
• Pressure in the cylinder is exhausted when the air supply at
“P” port is lost or locked out.
• L-O-X ® valve provides lockable shutoff of air supply, and
exhausting of trapped downstream air.
IMPORTANT NOTES and CAUTIONS:
» For cylinder to move, energizing of solenoids A and C or B and
C must occur simultaneously.
NOTE: See Installation and Troubleshooting on page 6.