One-way flow control valves VFOF
Subject to change – 2014/09
2
è Internet: www.festo.com/catalogue/...
One-way flow control valves VFOF
Key features and product range overview
Features
Minimal height
High flow rate
Can be rotated horizontally through
360° in assembled state
Actuation direction 1 can be
changed by repositioning the
housing
Greater functionality thanks to
function combinations
1
1
2
3
4
-H- Note
The following sequence must be
observed when assembling the
individual components:
1) Press thrust ring 2 into the
housing until it fits tightly.
2) Insert hollow bolt 3 into the
opening.
3) Push sealing ring OK 4 over
the thread of the hollow bolt.
Product range overview
Function Valve function Design Type Pneumatic
connection 1
Pneumatic
connection 2
qnN
1)
Adjusting
element
è Page/
Internet
[l/min]
One-way flow control
valves
Standard
Exhaust air
one-way flow
control function
VFOF QS-6, QS-8 Gx, G¼ 250 … 650 Internal hex 3
Function combination
Exhaust air
one-way flow
control function
VFOF QS-6, QS-8 Gx, G¼ 240 … 590 Internal hex 6
1) Standard nominal flow rate in flow control direction.
-V- New
2014/09 – Subject to change
3
è Internet: www.festo.com/catalogue/...
One-way flow control valves VFOF
Type codes
VFOF – L E – H – G18 – Q6
Type
VFOF One-way flow control valve, flat design
Design
L L-shaped outlet
Valve function
E Exhaust air one-way flow control function
Adjusting element
H Internal hex
Pneumatic connection 2
G18 Thread Gx
G14 Thread G¼
Pneumatic connection 1
Q6 Push-in connector QS-6
Q8 Push-in connector QS-8
-V- New
Subject to change – 2014/09
4
è Internet: www.festo.com/catalogue/...
One-way flow control valves VFOF
Technical data
One-way flow control function
Exhaust air
-M- Standard nominal flow rate
250 … 650 l/min
-Q- Temperature range
–10 … +60 °C
-L- Operating pressure
0.2 … 10 bar
One-way flow control valves are used
to adjust the flow rate and produce a
specific change in the piston speed
during the advance and return stroke
when used with pneumatic drives.
This is done through suitable
restriction of the flow rate of
compressed air.
The flow control function is realised by
means of an adjustable annular gap in
the housing. This gap can be
increased or decreased by turning the
regulating screw with internal hex.
General technical data
Valve function Exhaust air one-way flow control function
Pneumatic connection 2 Gx G¼
Pneumatic connection 1 QS-6 QS-8
Adjusting element Internal hex
Actuation type Manual
Type of mounting Screw-in
Mounting position Any
Nominal tightening torque [Nm] 3 _20% 11 _20%
Perm. actuation torque for
regulating screw
[Nm] 1 1.5
Rotatability [°] 360 (continuous rotation not permitted)
Operating and environmental conditions
Operating pressure [bar] 0.2 … 10
Operating/pilot medium Compressed air according to ISO 8573-1:2010 [7:4:4]
Note on operating/pilot medium Lubricated operation possible (in which case lubricated operation will always be required)
Ambient temperature [°C] –10 … +60
Temperature of medium [°C] –10 … +60
Storage temperature [°C] –20 … +70
Corrosion resistance class CRC
1)
2
1) Corrosion resistance class CRC 2 to Festo standard FN 940070
Moderate corrosion stress. Indoor applications in which condensation may occur. External visible parts with primarily decorative requirements for the surface and which are in direct contact with the ambient atmo
sphere typical for industrial applications.
Materials
Sectional view
One-way flow control valve
1 Housing PBT
2 Hollow bolt Wrought aluminium alloy
3 Sleeve Wrought aluminium alloy
4 Regulating screw Brass
5 Releasing ring POM
– Seals NBR
Note on materials RoHS-compliant
-V- New
2
134
5
2014/09 – Subject to change
5
è Internet: www.festo.com/catalogue/...
One-way flow control valves VFOF
Technical data
Standard nominal flow rate qnN [l/min] and standard flow rate qN [l/min] as a function of turns of the adjusting screw n
VFOF-…-G18-Q6 VFOF-…-G14-Q8
qnN
qn
Flow rate value tolerance: _20%
Dimensions Download CAD data è www.festo.com
Type Connection Tubing O.D. B1 H1 H2 H3 H4 L1 L2 L3 ß 1 ß 2
D1 D2
VFOF-…-G18-Q6 Gx QS-6 21.7 19.4 8.6 5 14 39.9 32.4 12.2 12 2.5
VFOF-…-G14-Q8 G¼ QS-8 24.7 28.4 12.6 5.4 19.6 56.3 46.1 15.5 15 2.5
Ordering data – Exhaust air one-way flow control function
Pneumatic
connection
Standard nominal flow rate qnN
at 6 bar } 5 bar
Standard flow rate qn
at 6 bar } 0 bar
Weight Part No. Type
In flow control
direction
In non-return
direction
In flow control
direction
In non-return
direction
2 1 [l/min] [l/min] [l/min] [l/min] [g]
Gx QS-6 250 150 … 260 420 460 … 540 13.9 1526931 VFOF-LE-H-G18-Q6
G¼ QS-8 650 300 … 650 1,100 840 … 1,100 32.9 1505391 VFOF-LE-H-G14-Q8
-V- New
Subject to change – 2014/09
6
è Internet: www.festo.com/catalogue/...
One-way flow control valves VFOF, function combination
Type codes
VFOF – L E – BA H – G18 – Q6
Type
VFOF One-way flow control valve, flat design
Design
L L-shaped outlet
Valve function
E Exhaust air one-way flow control function
Additional function
BA Piloted non-return function, manual exhaust function
Adjusting element
H Internal hex
Pneumatic connection 2
G18 Thread Gx
G14 Thread G¼
Pneumatic connection 1
Q6 Push-in connector QS-6
Q8 Push-in connector QS-8
-V- New
2014/09 – Subject to change
7
è Internet: www.festo.com/catalogue/...
One-way flow control valves VFOF, function combination
Technical data
One-way flow control function
Exhaust air
-M- Standard nominal flow rate
240 … 590 l/min
-Q- Temperature range
–10 … +60 °C
-L- Operating pressure
0.2 … 10 bar
The one-way flow control valve
VFOF-LE-BAH is a valve with a function
combination consisting of an exhaust
air one-way flow control function and
a piloted non-return function with
manual exhaust function.
The exhaust air one-way flow control
function is used to manually adjust
the advance/return speed of the
piston rod of a pneumatic drive.
The flow control function is realised by
means of an adjustable annular gap in
the housing. This gap can be
increased or decreased by turning the
regulating screw with internal hex.
The piloted non-return function can be
used for a temporary intermediate
stop. If a pilot signal is applied,
exhaust air flow control is active. If no
pilot signal is applied, the valve shuts
off the exhaust air from the drive and
the drive stops temporarily.
The integrated manual exhaust
function can be used to manually vent
a pneumatic drive.
General technical data
Valve function Exhaust air one-way flow control function
Pneumatic connection 2 Gx G¼
Pneumatic connection 1 QS-6 QS-8
Pilot air connection 21 QS-6 QS-8
Adjusting element Internal hex
Actuation type Manual
Type of actuation, piloted non-return function Pneumatic
Manual exhaust function Non-detenting
Type of mounting Screw-in
Mounting position Any
Switching time Off [ms] 9 11
On [ms] 6 8
Nominal tightening torque [Nm] 3 _20% 11 _20%
Perm. actuation torque for
regulating screw
[Nm] 1
Rotatability [°] 360 (continuous rotation not permitted)
Operating and environmental conditions
Operating pressure for entire
temperature range
[bar] 0.2 … 10
Pilot pressure [bar] 2 … 10
Operating/pilot medium Compressed air according to ISO 8573-1:2010 [7:4:4]
Note on operating/pilot medium Lubricated operation possible (in which case lubricated operation will always be required)
Ambient temperature [°C] –10 … +60
Temperature of medium [°C] –10 … +60
Storage temperature [°C] –20 … +70
Corrosion resistance class CRC
1)
2
1) Corrosion resistance class CRC 2 to Festo standard FN 940070
Moderate corrosion stress. Indoor applications in which condensation may occur. External visible parts with primarily decorative requirements for the surface and which are in direct contact with the ambient atmo
sphere typical for industrial applications.
-V- New
Subject to change – 2014/09
8
è Internet: www.festo.com/catalogue/...
One-way flow control valves VFOF, function combination
Technical data
Materials
Sectional view
One-way flow control valve
1 Housing PBT
2 End cap PBT
3 Hollow bolt Wrought aluminium alloy
4 Sleeve Wrought aluminium alloy
5 Regulating screw Brass
6 Releasing ring POM
– Cover ES-BE
– Seals NBR
Note on materials RoHS-compliant
Standard nominal flow rate qnN in flow control direction at 6 > 5 bar
as a function of turns of the adjusting screw n
Standard flow rate qn in flow control direction at 6 > 0 bar
as a function of turns of the adjusting screw n
VFOF-…-G18-Q6
VFOF-…-G14-Q8
Flow rate value tolerance: _20% VFOF-…-G18-Q6
VFOF-…-G14-Q8
Flow rate value tolerance: _20%
Minimum pilot pressure p21 as a function of operating pressure p1
-V- New
21
3
45
6
2014/09 – Subject to change
9
è Internet: www.festo.com/catalogue/...
One-way flow control valves VFOF, function combination
Technical data
Dimensions Download CAD data è www.festo.com
Type Connection Tubing O.D. B1 B2 H1 H2 H3 H4 L1 L2 L3 L4 L5 ß 1 ß 2
D1 D2
VFOF-…-G18-Q6 Gx QS-6 29.5 15 19.4 5 14.1 1.5 60.3 52.8 23.8 9.7 7.5 12 2.5
VFOF-…-G14-Q8 G¼ QS-8 39.5 20.5 28.2 5.6 21 2 76.8 66.8 30 11.1 10 15 2.5
Ordering data – Exhaust air one-way flow control function
Pneumatic
connection
Pilot air
connec
tion
Standard nominal flow rate qnN
at 6 bar } 5 bar
Standard flow rate qn
at 6 bar } 0 bar
Weight Part No. Type
In flow con
trol direction
In non-return
direction
In flow con
trol direction
In non-return
direction
2 1 21 [l/min] [l/min] [l/min] [l/min] [g]
Gx QS-6 QS-6 240 150 … 230
120 … 220
1)
420 400 … 460
400 … 460
1)
28.6 8001459 VFOF-LE-BAH-G18-Q6
G¼ QS-8 QS-8 590 315 … 540
310 … 540
1)
940 830 … 1,000
840 … 1,000
1)
73.9 1927030 VFOF-LE-BAH-G14-Q8
1) Unactuated
-V- New
