Flow control valves
Subject to change – 2013/09
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Flow control valves
Key features
Function
Flow control or one-way flow control
valves regulate the piston speed of
pneumatic drives during advance and
return strokes. This is done through
suitable restriction of the flow rate of
compressed air in exhaust air or
supply air direction. With the one-way
flow control valve GRLA or GRLZ, the
flow control function works in one dir-
ection only (exhaust air or supply air);
the non-return function works in the
opposite direction. With the flow
control valve GRLO, the flow control
function is active in both directions.
The flow control function creates an
adjustable annular gap inside the
valve. This gap can be increased or de-
creased by turning the k nurled screw
or slotted head screw. The required
restriction can be set with the help of
this adjustment component.
-H- Note
The documentation for the one-way
flow control valves can be found at
www.festo.com/catalogue
General information
Standard nominal flow rate qnN Exhaust air one-way flow control
function
Flow measurement circui t
The standard nominal flow rate qnNis
the flow rate based on standard
conditions at an operating pressure of
p1 = 6 bar and an output pressure of
p2 = 5 bar, measured at room
temperature t = 20 °C.
Pressure gauge Pressure gauge
Flow meter
(flow measuring device)
Flow control val veTest specimen
p
1
p
2
p
1
Operating pressure
p
2
Output pressure
Standard flow rate qn
The standard flow rate i s measured at
an operating pressure of p1 = 6 bar
and an output pressure with respect
to atmospheric pressure (p2 = 0 bar).
Supply air one-way flow control
function
Flow control function in both
directions
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Flow control valves
Key features
Flow control functions and range of applications
Application Description Application Description
Double-acting cylinder with one-way flow control valve
Exhaust air one-way flow control function Supply air one-way flow control function
Speed adjustment through exhaust air
flow control. Uncontrolled supply air
and controlled exhaust air move the
piston between air cushi ons (improves
motion, even with load changes).
Adjustable speed during advance and
return strokes. The flow rate is identical
in both directions.
Single-acting cylinder with one-way flow control valve Single-acting cylinder with flow control valve
Exhaust air and supply air one-way flow control function Flow control function in both directions
Adjustable speed during advance and
return strokes. The flow rate can be
adjusted differently for both directions.
Speed adjustment through flow control
on both sides is often applied in the
case of single-acting or small cylinders.
The benefit of this application lies in its
simplicity.
Application examples
Mini slide SLT Flat cylinder DZF Multimount cylinder DMM
Subject to change – 2013/09
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Flow control valves
Produ ct range overview
Version Valve function Version Type Connection
direction
Pneumatic
connection 1
Pneumatic
connection 2
qnN
1)
Adjustment
component
Page/
Internet
[l/min]
Standard Metal
Flow control
function
GRLO Elbow outlet M5 M5 95 Slotted head
screw
6
M5 PK-3 83 Slotted head
screw
6
Mini Metal
Flow control
function
GRLO Elbow outlet M3, M5 QS-3, QS-4 40 … 41 Slotted head
screw
8
M3 M3 18 Slotted head
screw
10
GRGO Parallel outlet M3 QS-3 41 Slotted head
screw
8
In-line
installation
Polymer
Flow control
function
GRO Inline QS-3, QS-4,
QS-6
QS-3, QS-4,
QS-6
25 … 160 Knurled screw gro
1) Standard nominal flow rate in direction of flow control.
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Flow control valves
Type codes
GRLO /GRGO
GRLO
– M5 – PK-3 – – B
Type
GRLO Flow control valve, elbow outlet
GRGO Flow control val ve, parallel outlet
Pneumatic connection 1
M3 Male thread M3
M5 Male thread M5
Pneumatic connection 2
– Female thread (connection size as for connection 2)
QS-3 Push-in connector for tubing O.D. 3 mm
QS-4 Push-in connector for O.D. tubing 4 mm
PK-3 Push-in connector for tubing I.D. 3 mm
Flow rate characteristic
LF Low flow
MF Medium flow
Generation
B Bseries
C Cseries
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Flow control valves GRLO, standar d
Technical data – Female thread/barbed connector, metal
Functi on
-M- Flow rate
83 … 95 l/min
-Q- Temperature range
–10…+60°C
-L- Operating pressure
0…10bar
GRLO-M5 GRLO-M5-PK
General technical data
Valve function Flow control function
Pneumatic connection 1 M5 M5
Pneumatic connection 2 M5
1)
PK-3
Adjustment component Slottedheadscrew
Type of mounting Screw-in
Mounting position Any
Max. tightening torque [Nm] 1.5 1.5
1) -H- Note: This product conforms to ISO 1179-1 and ISO 228-1.
Operating and environmental c onditions
Operating pressure [bar] 0…10
Operating medium Compressed air in accordance with ISO 8573-1:2010 [7:4:4]
Note on operating/pilot medium Operation with lubricated medium possibl e (in which case lubricated operation will always be requir ed)
Ambient temperature [°C] –10 … +60
Temperature of medium [°C] –10 … +60
Storage temperature [°C] –10 … +40
Standard nominal flow rate qnN at 6 > 5bar
as a function of turns of the adjusting screw n
Standard flow rate qn at 6 > 0bar
as a function of turns of the adjusting screw n
n
qnN [l/min]
n
qn [l/min]
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Flow control valves GRLO, standar d
Technical data – Female thread/barbed connector, metal
Materials
Sectional view
Flow control val ve
1 Adjusting screw Brass
2 Swivel connection Die-cast zinc
3 Threaded plug Nickel-plated brass
– Seals NBR
Note on materials RoHS-compliant
Dimensions Download CAD data www.festo.c om
Female thread Push-in connector
3 Barbed connector
-H- Note: This product conforms to ISO 1179-1 and to ISO 228-1
Type Connection Nominal size B H H1 L
max.
L1 L2 ß
D [mm]
Female thread
GRLO-M5 M5 2 10 –0.15 17.5 12.5 17.6 4 ±0.3 7.1 9
Push-in connector
GRLO-M5-PK-3 M5 2 10 –0.15 19.7 14.7 17.6 4 ±0.3 8.5 9
Ordering data
Pneumatic
connection
Standard nominal flow rate qnN
at 6 > 5bar
in direction of flow control
Standard flow rate qn
at 6 > 0bar
in direction of flow control
Weight Part No. Type
1 2 [l/min] [l/min] [g]
Slottedheadscrew
M5 M5 95 169 11 151181 GRLO -M5-B
M5 PK-3 83 140 10 151182 GRLO-M5-PK-3-B
2
1
3
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Flow control valves GRLO/GRGO , mini
Technical data – Push-in connector QS, metal
Functi on
• Low flow: precision adjustment for
low speed
-M- Flow rate
40 … 41 l/min
-Q- Temperature range
–10…+60°C
-L- Operating pressure
0…10bar
GRLO GRGO
General technical data
Valve function Flow control function
Pneumatic connection 1 M3 M5
Pneumatic connection 2 QS-3 QS-3, QS-4
Adjustment component Slottedheadscrew
Type of mounting Screw-in
Mounting position Any
Max. tightening torque [Nm] 0.3 1.5
Operating and environmental c onditions
Operating pressure [bar] 0…10
Operating medium Compressed air in accordance with ISO 8573-1:2010 [7:4:4]
Note on operating/pilot medium Operation with lubricated medium possibl e (in which case lubricated operation will always be requir ed)
Ambient temperature [°C] –10 … +60
Temperature of medium [°C] –10 … +60
Storage temperature [°C] –10 … +40
Standard nominal flow rate qnN at 6 > 5bar
as a function of turns of the adjusting screw n
Standard flow rate qn at 6 > 0bar
as a function of turns of the adjusting screw n
GRLO/GRGO-M3 GRLO/GRGO-M3
n
qnN [l/min]
qn [l/min]
n
GRLO-M5 GRLO-M5
n
qnN [l/min]
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Flow control valves GRLO/GRGO , mini
Technical data – Push-in connector QS, metal
Materials
Sectional view
Flow control val ve
1 Adjusting screw Brass
2 Swivel connection Die-cast zinc
3 Releasing ring POM
4 Threaded plug Brass
– Seals NBR
Note on materials RoHS-compliant
Dimensions Download CAD data www.festo.c om
GRLO, elbow outlet GRGO, parallel outlet
Type Connection Nominal size Tubing O.D. B H H1 H2 L
max.
L1 L2 L3 ß
D [mm] D1
GRLO M3 1.4 3
8 –0.15 20 15.8
–
16.6 2.3 +0.15/–0.3 7
– 7M5 1.4 3
9.8 –0.15 22.4 18.4 17.7 3.1 +0.15/–0.35 7.3
1.4 4
9.8 –0.15 22.2 18.2 17.7 3.1 +0.15/–0.35 7.3
GRGO M3 1.4 3 8 –0.15 18 14 9.25 16.6 2.3 +0.15/–0.3 7.5 22 7
Ordering data
Pneumatic
connection
Standard nominal flow rate qnN
at 6 > 5bar
in direction of flow control
Standard flow rate qn
at 6 > 0bar
in direction of flow control
Weight Part No. Type
1 2 [l/min] [l/min] [g]
Slottedheadscrew
M3 QS-3 41 95 7 175042 GRLO-M3-QS-3
M5 QS-3 40 80 9 175054 GRLO-M5-QS-3-LF-C
QS-4 40 80 9 175057 GRLO-M5-QS-4-LF-C
M3 QS-3 41 95 14 175045 GRGO-M3-QS-3
2
4
1
3
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Flow control valves GRLO, mini
Technical data – Female thread, metal
Functi on
-M- Flow rate
0…18l/min
-Q- Temperature range
–10…+60°C
-L- Operating pressure
0…10bar
General technical data
Valve function Flow control function
Pneumatic connection 1 M3
Pneumatic connection 2 M3
Adjustment component Slottedheadscrew
Type of mounting Screw-in
Mounting position Any
Max. tightening torque [Nm] 0.3
Operating and environmental c onditions
Operating pressure [bar] 0…10
Operating medium Compressed air in accordance with ISO 8573-1:2010 [7:4:4]
Note on operating/pilot medium Operation with lubricated medium possibl e (in which case lubricated operation will always be requir ed)
Ambient temperature [°C] –10 … +60
Temperature of medium [°C] –10 … +60
Storage temperature [°C] –10 … +40
Standard nominal flow rate qnN at 6 > 5bar
as a function of turns of the adjusting screw n
Standard flow rate qn at 6 > 0bar
as a function of turns of the adjusting screw n
n
qnN [l/min]
Materials
Sectional view
Flow control val ve
1 Adjusting screw Brass
2 Swivel connection Die-cast zinc
3 Threaded plug Nickel-plated brass
– Seals NBR
Note on materials RoHS-compliant
2
1
3
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Flow control valves GRLO, mini
Technical data – Female thread, metal
Dimensions Download CAD data www.festo.c om
Slottedheadscrew
Type Connection Nominal size B H H1 L
max.
L1 L2 ß
D [mm]
GRLO M3 0.8 5 –0.1 9 6.5 13.3 2.5 +0.15/–0.3 6.4 4.5
Ordering data
Pneumatic
connection
Standard nominal flow rate qnN
at 6 > 5bar
in direction of flow control
Standard flow rate qn
at 6 > 0bar
in direction of flow control
Weight Part No. Type
1 2 [l/min] [l/min] [g]
Slottedheadscrew
M3 M3 18 33 2 175039 GRLO -M3
