VOSS 232 User manual

B 232 Assembly instructions
VOSS quick connect system 232
Experience plus ideas

These assembly instructions
are intended for qualified fit-
ters of pneumatic systems in
commercial vehicles.
1. Introduction
Nylon tube lines are in general
use today in pneumatic brak-
ing systems in commercial
vehicles. Nylon tubes are in-
sensitive to corrosion, vibrati-
on and torsional stress in
vehicle bodywork.
The following factors are
essential for their functional
reliability:
- Correct material and proper
handling
- Appropriate connection fit-
tings
- Correct assembly
As a connecting element
between nylon tubing and
components, the VOSS quick
connect system 232 permits
rapid and safe connection.
2. Nylon tubing
The properties of nylon tubing
and details of its use in com-
mercial vehicles are defined in
the following standards:
DIN 73 378
Polyamide tubing for motor
vehicles
DIN 74 324, Part 1
Air braking systems - thermo-
plastic tubing; part 1: require-
ments and tests
DIN 74 324, Part 2
Air braking systems - thermo-
plastic tubing; part 2: guide
for assembling
Only nylon tubing which con-
forms to DIN 74324 part 1
and made of polyamide 11 or
polyamide 12 may be used.
2
VOSS quick connect system 232 for pneumatic systems in commercial vehicles
VOSS quick connect system 232

Plug:
1Plug body Brass or PA11 – GF30
2 Dirt-protection and NBR 60
pretension o-ring
3 O-ring seal EPDM 60
Coupling element:
4 Male nut Brass
5 Thread-sealing o-ring NBR 70
6 Fixing ring POM
Retaining element:
7 Retaining clips Spring steel
8 Retaining ring POM
Other:
9 Nylon tubing
10 Component
3.2 Individual
components/materials
The VOSS quick connection
system 232 consists of two
main assemblies: the plug
with its fir-tree and the cou-
pling element.
Plug
The plug has a broad retaining
groove, the reverse flank of
which is inclined at 45°. This
protects the clips which snap
into place during assembly
from being subject to excess
tension.
There are two additional
grooves, both for o-rings. The
first o-ring (3) functions as a
seal against the medium being
transported.
The second, exterior o-ring
prevents contamination from
penetrating the connection.
In addition, the specially
designed groove geometry
exerts an axial pre-tensioning
force on the plug, when the
clips have snapped into place.
The reduced plug diameter
above the exterior o-ring (2)
acts as a stabilising factor on
the coupling element and at
the same time provides opti-
cal assistance during assem-
bly.
Coupling element
The coupling element is
screwed tightly into the com-
ponent. An o-ring acts as a
seal in the threaded port (5).
The two-step retaining ele-
ment is clipped to the male
nut (4) by means of a fixing
ring (6). The retaining element
contains the retaining ring (8)
and two metal clips (7) which
lock into place in the retaining
groove once the plug has
been pressed into the end
position.
3. VOSS quick connect
system 232
The VOSS quick connect sys-
tem 232 permits rapid assem-
bling of nylon tubes to com-
ponents. The only tool re-
quired for disconnection is a
wrench (for width across flats,
see section 4.3).
The connecting fittings are
made from brass, die-cast alu-
minium, die-cast zinc, alumini-
um or nylon, depending
on the general conditions. In
their standard design, the
plugs are available in brass.
Individual plug variants are
also available in nylon (PA 11 –
GF30). Nylon and brass plugs
are mutually replaceable. The
dimensions of nylon plugs dif-
fer from those of brass plugs
(see table in section 4.2.2
page 6).
The drawings and tables of
dimensions contained in
these assembly instructions
refer to the brass plug model.
When inserting the nylon plug
into the tube, due considera-
tion has to be given to the
greater length of the fir-tree
compared to the brass model
(see section 4.2.2).
3.1 Range of application
The individual components in
the VOSS quick connect sys-
tem 232 are designed for a
working temperature range of
between -40°C and +100°C.
Their rated operating pres-
sure is 15,5 bar and is limited
by the compressive strength
of the nylon tubing used.
Possible applications for other
service conditions are avail-
able on request.
3
Individual components of VOSS quick connect system 232
CAUTION!
Due to the different material properties, particular
attention should be paid to the instructions for
nylon plugs contained in section 6.
1
2
3
9
4
5
6
7
8
10

CAUTION!
The chart obtains only for metallic housings.
For nylon housings the VOSS V-thread
has to be used.
Screw-in thread Nominal size Fir-tree for tubes
NS O.D. x wall thickness
M 16 x 1.5 8 6 x 1
8 x 1/9 x 1.5
10 x 1,25
10 x 1/11 x 1.5
12 x 1.5
M 22 x 1.5 12 6 x 1
8 x 1/9 x 1.5
10 x 1.25
10 x 1/11 x 1.5
12 x 1.5/14 x 2.5
12,5 x 1.25/14 x 2
16 x 2
VOSS quick connect system 232, functional diagram
Retention of the plug in the
first snap-in stage thus solves
the safety problem of faulty
insertion, leading to sudden
failure of the connection and
subsequent breakdown of the
entire system. Compensation
for the minor leakage is
topped up by the compressor.
3.4 Product range
The VOSS quick connect
system is available in nominal
sizes 8 and 12.
Please refer to the table below
for possible combinations of
plug size and nylon tubing
dimensions.
The entire range of parts and
accessories for the VOSS
quick connect system 232 is
contained in catalogue 232.
3.3 Functional description
The coupling element forms
the connection to the compo-
nent. Connection is made by
screwing the coupling element
into an appropriate port.
Suitable ports are the industri-
ally standard moulded port for
the VOSS quick connect sys-
tem 230 and special port
shapes agreed with VOSS for
the application in question.
On request, we will be
pleased to supply design
specifications for the appropri-
ate port.
The connection between a
nylon tube and a component
is made by sliding the plug
into the coupling element.
When this is done the plug is
kept in place by a two-stage
retaining element which, once
it has reached its second
snap-in location, is automati-
cally shifted from the push-in
to the locking position by
means of axial compression
and the pressure of the com-
pressed air.
Should the second snap-in
stage not be reached due to
insufficient insertion force or
other unfavourable circum-
stances, the plug is safe from
disconnection as soon as the
retaining element has snap-
ped into the first stage.
It is possible to push the
retaining element into this first
snap-in stage by applying very
little force. In this retention
position, the connection has
an intended leakage path.
Incomplete connections may
be noticed by an acoustic
warning signal and a drop in
pressure.
4
Possible combinations
of thread size, nominal size and tube dimensions
First snap-in
stage Second snap-in stage
Axial
compression
Acoustic warning
signal through
leakage path

CAUTION!
The connection between nylon tubing and fir-tree
must under no circumstances be secured by
hose clips or by clamping sleeves.
Nylon tube pliers
4 Assembly instructions
4.1 Cutting nylon tubing to
length
The nylon tube must be cut
off square. A saw may not be
used for this purpose as the
possible formation of burrs will
jeopardise the sealing capabi-
lity of the connection. For cut-
ting nylon tubing to the cor-
rect length, we recommend
the use of the VOSS cutting
pliers shown on the right,
which ensure that the tubing
is cut squarely and cleanly.
Subsequent treatment of the
cut surface such as deburring
is no longer necessary then.
4.2 Insertion of the fir-tree
in nylon tubing
The following has to be
observed when pressing the
fir-tree into the nylon tube:
-Insertion procedure must be
carried out at room tempera-
ture
-Nylon tube may not be
heated
-Fir-tree must be undamaged
as the connection to the
nylon tubing will otherwise
not be tight
-Fir-tree must be clean and
free of any grease
5
4.2.1 Insertion of the
fir-tree with the nylon
tube collet
Insert the nylon tube into the
opened pliers in such a way
that the end of the tube
extends approx. 2 mm for
brass plugs and approx.
6 mm for nylon plugs from
the side of the pliers without
serration. Fix the nylon tube
into place with the grip
mechanism. The clamping
force exerted may be varied
by means of the adjusting
screw.
Press the fir-tree as far as
possible into the end of the
tube manually. Then drive the
plug into the polyamide tube
with the aid of a plastic ham-
mer until the fir-tree is fully
covered by the tube. The plug
has to be protected by a plas-
tic cap.
Nylon tube collet
Insertion of the fir-tree with nylon tube collet
VOSS
68 10 12 16
approx. 2mm
for brass plugs
aprox. 6mm
for nylon plugs

NS d1Tube d3d4a (mm)
(mm) O.D. x wall thickness (mm) (mm)
(brass/nylon)
NS 8 9.7 6 x 1 4.6 4.0 16
8 x 1/9 x 1.5 6.9 6.0 16
10 x 1.25 8.1 7.5 22
10 x 1/11 x 1.5 9.0 8.0 22
12 x 1.5 10.3 9.0 22
NS 12 15.2 6 x 1 4.6 4.0 16
8 x 1/9 x 1.5 6.9 6.0 16
10 x 1.25 8.1 7.5 22
10 x 1/11 x 1.5 9.0 8.0 22
12 x 1.5/14 x 2.5 10.3 9.0 22/26
12,5 x 1.25/14 x 2 11.2 10.0 22
16 x 2 13.6 12.0 25
Manual assembly tool
4.2.3 Protective cap
All plugs are supplied with a
protective cap to protect the
neck of the plug and the o-
rings from damage and dirt.
This protective cap should not
be removed until immediately
before final assembly.
6
4.2.2 Insertion of the
fir-tree with manual
assembly tool
The tube clamping jaws
should be turned in the cor-
rect position until they match
the outer diameter of the tube
to be mounted. A tool insert
corresponding to the plug to
be fitted (NS 8 or NS 12,
straight or shaped plug)
should then be placed into
the fixture.
The diameter d3 of the fir-tree
should match the internal
diameter of the nylon tube
(see table). This ensures that
the required pretension pres-
sure of tube onto the fir-tree
is reached.
Next place the nylon tube in
the jaws, allowing it to pro-
trude by the length L (see
fig.), and firmly secure the
nylon tube by tightening the
vicegrip. The clamping force
exerted may be varied by
means of the adjusting screw.
The plug to be fitted should
then be placed in the tool
insert with a protective cap
and the transport bar pressed
manually towards the nylon
tubing until the fir-tree is pre-
centred in the tube end.
Now the nylon tube can be
pressed onto the plug as far
as the end of the fir-tree by
using the insert lever.
Outline of tube and plug dimensions
Possible combinations
of tube dimensions and fir-tree dimensions
L ≥a+2 mm
d4
a
d1
d3

tection and pretension o-ring
while being pressed into the
coupling element, until both
clips snap into place in the
groove of the plug.
The first clip snaps into place
when only very little force is
applied. In this initial retention
position, the connection is
already secured against unin-
tentional loosening, but it is
not yet leak-tight. The con-
nection ist not fully sealed until
the second clip snaps into
Thread sizes Nominal size Across flats Tightening
torque
NS Nm
M 16 x 1.5 8 19 10 - 17
M 22 x 1.5 12 24 10 - 17
Coupling element:
1 Male nut Brass
2 Thread-sealing o-ring NBR 70
3 Fixing ring POM
4 Retaining element Spring steel/POM
4.3 Assembly of the
coupling element
In order to achieve safe func-
tioning, the connecting port
should be cleaned before fit-
ting the coupling element.
In particular, any residue of
paint still attached to the
region of the sealing lip should
be removed. Care is also be
taken to ensure that the
thread of the component is at
right angles to the contact
surface of the coupling ele-
ment.
The coupling element consists
of a male nut (1) with greased
thread-sealing o-ring (2) and
retaining element (4) clipped
into place with a fixing ring (3).
It is available from the factory
with or without paint protec-
tion stickers. If there is a paint
protection sticker on the front
of the coupling unit, it should
not be removed. The coupling
unit is screwed hand-tight
into the connecting port.
When the coupling element is
inserted into the thread, the
fixing ring acts to pre-align
the coupling element, thus
facilitating the assembly.
Now the coupling element
should be tightened with a
torque wrench. For this pur-
pose, the flap of the paint
protection sticker should be
folded upward. The recom-
mended tightening torques
are listed in table on the right.
The values quoted are valid
both for metal (die-cast alumi-
nium, die-cast zinc) and for
nylon casings (PA-GF30) with
VOSS V-thread.
Automatic VOSS assembly
tools are available on request
for high volume assembly.
7
4.4 Connecting line to
component
Now the protective cap can
be removed from the plug
(see section 4.2.3) and the
paint protection sticker can be
removed from the coupling
element (see section 4.3).
Slide plug with nylon tube fit-
ted to fir-tree into the port of
the coupling element. The
plug must overcome the axial
force exerted by the dirt-pro-
place. To conclude the inser-
tion process, check the clips
have snapped into place cor-
rectly by pulling in the oppo-
site direction from that used
for insertion. Always ensure
that the connector does not
sit at a false angle in the port.
It should not be possible to
pull back the connector when
checking whether it has been
correctly fitted.
The connection has been cor-
rectly made, if after pulling
back the plug the shoulder of
the plug above the exterior
(dirt-protection and preten-
sion) o-ring is located below
the top face end of the cou-
pling element and thus the o-
ring is not visible.
Incorrect connections, i.e.
plug connectors in the first
stop position, can be
reconnected to the second
stop position, also if the
system is pressurized (< 7
bar). This will not result in
damage. Whether
reconnection is possible also
depends on the possible
insertion force at the
installation location.
Tightening torque of VOSS quick connect system 232
Individual components of the coupling element
1
2
3
4

CAUTION!
Connections which have not snapped into place
can impair braking performance and may even
lead to failure of the entire pneumatic system.
8
4.5 Disconnecting and
reassembling
The pneumatic line connected
must be free of any pressure
before it is detached. If the
plug is detached while the line
is pressurised, it can cause
personal injury and damage to
connecting components or to
the pneumatic unit. These
damaged components must
then be replaced. All individual
components must be cleaned
before reassembly.
In order to replace compo-
nents, loosen the male nut
and remove the connection.
The nylon tube with plug and
coupling element with o-ring
need not to be separated.
Check the port on the new
unit is clean. Then re-grease
the thread-sealing o-ring,
screw in coupling element
with plug, fitted with nylon
tube and tighten male nut.
(For tightening torque, see
section 4.3).
Final assembly:
Inserting plug and subsequently pulling back to check
correct fitting
Final assembly:
Incomplete connection at first snap-in stage; the dirt-protection
and pretension o-ring is visible after pulling back the plug.

9
4.6 Assembly tools
The following tools are avail-
able from VOSS for assem-
bling quick connect system
232:
Series assembly
- VOSS type 56 assembly
machine for inserting fir-trees
into nylon tubing
Small series or individual
assembly
- Manual assembly tool
- Nylon tube collet
- Nylon tube pliers
Service case 1:
- 1 nylon tube collet for
external tube diam.
6, 8, 10, 12, 16
- 1 plastic hammer
- 1 nylon tube pliers
- 1 wrench 24/19 width
across flats
Service case 2:
-1 manual assembly tool with
tube clamping jaws for
external tube diam. 6, 8, 10,
and 12 and for external
diam. 11, 12, 14 and 16
- 1 tool insert for straight
connectors NS 8
- 1 tool insert for straight
connectors NS 12
- 1 tool insert for right-angle
connectors NS 8 with tubing
6 x 1, 8 x 1 and 9 x 1.5
- 1 tool insert for right-angle
connectors NS 12 with tub-
ing 6 x 1, 8 x 1 and 9 x 1.5
- 1 tool insert for right-angle
connectors NS 12 with tub-
ing 10 x 1.25 and 12 x 1.5
- 1 tool insert for right-angle
connectors NS 12 with tub-
ing 16 x 2
- 1 nylon tube pliers
- 1 wrench 24/19 width
across flats
Operating instructions and
product descriptions are avail-
able for the assembly tools
mentioned above; we will be
pleased to send you these on
request.
VOSS type 56 assembly machine

CAUTION!
Always use a new coupling element for reassem-
bling whenever male nut and plug have been dis-
connected.
Removing clips
10
5. Repairs
The components of VOSS
quick connect system 232 do
not wear or tear as a result of
operation.
Should any of the compo-
nents be damaged as a result
of inappropriate handling,
these may be replaced as
required.
5.1 Replacing the thread-
sealing o-ring
The old o-ring can be re-
moved when the system is
disconnected from the com-
ponent (see section 4.5).
Clean the groove in the cou-
pling element carefully and
check that it is not damaged.
The coupling element must be
replaced if there are any signs
of damage (see section 5.2).
Then replace the old o-ring
with a new one which has
been greased. All damage,
excess stretching or twisting
of the o-ring is to be avoided
when fitting.
5.2 Disconnecting coupling
element
Break the connection (see
section 4.5) and lever off the
fixing ring using a suitable tool
(see fig. 1). Take care that the
plug is not damaged in this
process.
Then pull the clips sideways
out of the retaining ring. This
can be done by inserting a
pointed tool through the slot
in the cage behind the clips
(see fig. 2).
Once the two clips and the
retaining ring have been
removed, the plug may be
pulled out of the male nut.
A suitable disassembly tool is
available on request.
1. Slide disassembly
tool onto fixing ring
3. Insert disassembly
hook from below
and pull out first clip
sideways
To reassemble, always use a
new coupling element when-
ever the plug has been
removed from the male nut. In
addition, the o-rings for the
plug must be checked,
replaced if necessary and re-
greased.
5.3 Replacing plug o-rings
The damaged o-ring can be
removed after disconnection
(see section 5.2). Clean the
groove carefully, and then
replace the old o-ring with a
new one which has been
greased. All damage, excess
stretching or twisting of the o-
ring is to be avoided when
refitting. This applies both to
the sealing o-ring and to the
dirt-protection and pretension
o-ring.
5.4 Lubrication of the
o-rings
In order to ensure the functio-
nal reliability of the o-rings,
use only grease that has
been tested and approved by
VOSS.
Approved lubricating greases
are:
- Bechen – Berulub
Hydrohaf 2
- Bechen – Berulub
Hydrohaf GR
- Klüber – SYNTHESO
GLEP 1
Levering off fixing ring
VOSS Part No. 5 9 94 47 10 00 Fig. 3
Disassembly tool for the coupling element
2. Remove fixing ring
by levering
Fig. 1
4. Insert disassembly
hook from above and
pull out second clip
sideways
Fig. 2