Festo DNG Series Setup guide

Repair
instructions (en)
Cylinder with piston rod
Standard cylinder to ISO 15552
DNG/DNGL/DNGLZ
DNGZK / DNGZS
7DNGa_en

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Imprint
at:
7DNGa_en (06.2013)
Copyright:
©Festo AG & Co. KG
Postfach
73726 Esslingen
Germany
Editorial team:
SC-S
Tel.:
+49 (0) 711 / 347-0
Fax:
+49 (0) 711 / 347-2144
E-mail:
[email protected]
Internet:
http://www.festo.com
Reproduction, distribution or sale of
this document or communication of
its contents to others without express
authorisation is prohibited. Offenders
will be liable for damages. All rights
reserved in the event that a patent,
utility model or design patent is
registered.
All product designations and brand
names used are the property of the
owners and not explicitly identied
as such.
All technical data are subject to change
according to technical updates.

3 / 28Festo 7DNGa_en
Preface
These repair instructions are valid for the cylinders with piston rod listed on
the title page to the exclusion of any liability claims.
Deviations compared to the descriptions in these repair instructions may arise
depending on the design and/or modication status of the cylinder with piston
rod. The user must check this prior to carrying out the repair and take the
deviation into consideration if necessary.
These repair instructions have been prepared with care.
Festo AG & Co. KG does not, however, accept liability for any errors in these
repair instructions or their consequences. Likewise no liability is accepted for
direct or consequential damage resulting from improper use of the products.
More detailed information on this can be found in chapter 8 "Liability".
The relevant regulations on occupational safety, safety engineering and
interference suppression as well as the stipulations contained in these repair
instructions must be observed when working on the products.

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Table of contents
1 Important information 5
1.1 About these repair instructions 5
1.2 Pictograms used in these repair instructions 5
1.3 General safety instructions 6
2 General product description 6
2.1 Functional description 6
2.2 Type codes (ascertaining the features of a cylinder) 7
2.3 Repair-relevant features 7
2.4 Mounting direction and bearing cap variants 8
3 Component overview 9
3.1 Component overview up to a piston diameter of 100 mm 9
3.2 Component overview from a piston diameter of 125 mm 11
4 Repair steps 13
4.1 Preparation 13
4.2 Visual inspection 13
4.3 Repairing the cylinders DNG / DNGL / DNGLZ / DNGZK and DNGLZS-… 13
4.3.1 Structure of the bearing cap 14
4.3.2 Removing the bearing and end caps 14
4.3.3 Replacing the piston components 15
4.3.4 Inserting the piston rod into the cylinder barrel 16
4.3.5 Repairing and attaching the bearing and end caps 16
4.4 Repairing the cylinders DNG / DNGL / DNGLZ / DNGZK / DNGLZS-…-S6 19
4.4.1 Structure of the bearing cap 19
4.4.2 Removing the bearing and end caps 20
4.4.3 Replacing the piston components 20
4.4.4 Inserting the piston rod into the cylinder barrel 21
4.4.5 Repairing and attaching the bearing and end caps 22
4.5 Repairing the adjustable end-position cushioning (PPV) 24
4.5.1 Disassembling the adjustable end-position cushioning (PPV) 25
4.5.2 Assembling the adjustable end-position cushioning (PPV) 25
5 Cleaning and greasing 26
5.1 Cleaning 26
5.2 Greasing 26
5.2.1 Extremelythingreaselm 26
5.2.2 Thingreaselm 26
5.2.3 Grease reservoir 26
6 Maintenance and care 26
7 Tools 27
7.1 Standard tools 27
7.2 Special tools 27
8 Liability 27

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1 Important information
1.1 About these repair instructions
This document contains important
information about the professional
repair of cylinders with piston rod
type DNG / DNGL / DNGLZ / DNGZK /
DNGZS.
The cylinders with piston rod DNG /
DNGL / DNGLZ / DNGZK / DNGZS are
fully repairable in the event of damage
caused by normal wear. The entire
cylinder must be replaced in the event
of damage to the cylinder barrel.
Before carrying out a repair,
the relevant chapter in these
instructions must be read in full
and followed consistently.
For reasons of clarity, these repair
instructions do not contain complete
detailed information. The following
documents should therefore also be
available when repairing the cylinder
with piston rod:
• Operating instructions for the
respective cylinder with piston rod
Contains information about the
control sections and connections
of the cylinder with piston rod as
well as the function, structure,
application, installation,
commissioning, maintenance
and care, etc. Can be found on the
Festo website (www.Festo.com).
• Spare parts documentation
Contains an overview of the spare
and wearing parts as well as
information on their installation.
Can be found in the online spare
parts catalogue on the Festo
website (spareparts.festo.com).
• Assembly aids
Contain an overview of available
assembly aids such as lubricating
greases, locking agents,
maintenance tools, etc. (aids
for assembly and maintenance).
Can be found in the online spare
parts catalogue on the Festo
website (www.Festo.com).
1.2 Pictograms used in these repair instructions
Warning
This sign indicates a dangerous situation for persons and/or the product. Failure to observe this warning can result in
injury to persons and/or damage to the device.
Note
This sign provides important tips and information that can make your work easier.
Environment
This sign provides information on the steps required for environmentally-friendly use of materials and equipment,
as well as the guidelines and regulations that may need to be observed.
Accessories
This sign contains information on accessories and attachments relevant to the context.
Documents
This sign contains references to other chapters or documents containing additional information.

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1.3 General safety instructions
Warning
The cylinder with piston rod must only be repaired by authorised and trained persons in accordance with the
specications in the technical documentation and using original spare parts.
Installation and repair by unauthorised and untrained persons, repairs using non-original spare parts as well as without
the technical documentation required for installation and/or repair are dangerous and therefore not permitted.
Repairs must only be carried out in conjunction with these repair instructions and the device-specic operating
instructions.
Note
Instead of carrying out the repair yourself, your local Festo sales ofce offers the option of having the repair carried
out by Festo.
Environment
Components and equipment replaced as part of a repair must be disposed of in accordance with the locally valid
environmental protection regulations.
2 General product description
2.1 Functional description
The piston moves in the cylinder barrel when the cylinder chamber is pressurised. The piston rod transmits the movement
to the outside. The advanced piston rod is retracted again when the other cylinder chamber is pressurised.
aA
aB
aC
aJ981 3 4 6 752 1Piston rod
2Piston rod seal
3Bearing cap
4Front adjustable end-position
cushioning
5Front compressed air connection
6Tie rod
7Cylinder barrel
8Cushioning boss
9Piston (one-piece)
aJ Cushioning boss
aA Rear adjustable end-position
cushioning
aB Rear compressed air connection
aC End cap
(with S2 : Rear bearing cap)

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2.2 Type codes (ascertaining the features of a cylinder)
The precise features of the current cylinder with piston rod can be ascertained with the help of the rating plate on
the cylinder. The type designation is located directly beneath the Festo logotype and describes the cylinder's features
separated by a hyphen (-).
Example:
DNG-32-100-PPV-A
36325 C508
p max: 12 bar
1
42
3
1Type designation
2Serial number
3Technical information
4Part number
The type designation on this rating plate provides the following information:
DNG Cylinder type DNG
32 Piston diameter 32 mm
100 Stroke 100 mm
PPV Adjustable end-position cushioning
ASensing option (magnetic piston)
Note
A list and description of all possible equipment features of the cylinder with piston rod can be found in the data sheet.
It is available on the Festo website (www.Festo.com).
2.3 Repair-relevant features
Some of the features that the cylinder with piston rod can be equipped with require a different repair approach. These are
referred to as "repair-relevant" features and are listed in the left-hand column in the table below.
If the cylinder to be repaired has one of these repair-relevant features, the appropriate repair description (see right-hand
column in the table below) must be used.
Note
A cylinder can only have one repair-relevant feature. It can additionally be equipped with one or more other features
(see middle column).
Cylinder and repair-relevant feature Other features Described from page
DNG / DNGL / DNGLZ / DNGZK / DNGLZS-… without repair-
relevant feature
PPV, A, S2, S3, S8 13
DNG / DNGL / DNGLZ / DNGZK / DNGLZS-…-S6
(heat-resistant seals up to a max. 120°C)
PPV, A, S3, S8 19
Example for the cylinder in chapter 2.2 "Type codes (ascertaining the features of a cylinder)"
Of the features in the sample cylinder, the feature "S6" is relevant to the repair. The description in chapter
4.4 "Repairing the cylinders DNG / DNGL / DNGLZ / DNGZK / DNGLZS-…-S6" on page 19 must therefore be used to
repair this cylinder with piston rod.

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2.4 Mounting direction and bearing cap variants
This diagram provides an overview of the orientation designations of the cylinder with piston rod as well as the different
variants of the bearing cap and seals for repair-relevant features.
Orientation:
Festo=product identi cation
(rating plate) as reference point
O = top
U = underneath
R = right
L = left
V = front
H = rear
Key features:
S6 = Heat-resistant seals

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3 Component overview
3.1 Component overview up to a piston diameter of 100 mm
This diagram is intended only to provide an overview of the individual components. To order spare and wearing parts, please use the
online spare parts catalogue on the Festo website (spareparts.festo.com).
1
11
9
11
29
27
10
14
15
16
10
22
17
20
22
18
23
19
24
20
21
23
25
26
16
12
13
5
28
2
3
4
5
1
3
4
6
8
7
5
18
17
22
17
20
22
18
19
24
20
21
18
17
17
20
18
19
24
20
21
18
17
30
6
8
7
9
6
8
7

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Item Designation Note
1 Hex nut
2 Retaining ring Only with -S6
3 Piston rod seal
4 Bearing
5 Collar nut Use screw locking agent
6 O-ring
7 Regulating screw
8 Serrated ring
9 Bearing cap
10 Sealing ring
11 Cushioning seal
12 Washer
13 Tie rod
14 Piston rod, secured against rotating DNGLZ and DNGLZ only
15 Piston rod
16 Cushioning boss
17 Lip ring (piston seal)
18 Piston, two-piece
19 Socket DNGLZ and DNGLZ only (piston rod, secured against rotating)
20 O-ring
21 Slip ring
22 O-ring Only at a piston diameter of 32 mm and 40 mm
23 Washer Only at a piston diameter of 32 mm
24 Ring magnet
25 Threaded coupling Not S2, use screw locking agent
26 Piston rod Only S2, use screw locking agent?
27 Cylinder barrel
28 Socket head screw DNGLZ and DNGZK only
29 Trunnion mounting DNGLZ and DNGZK only
30 End cap

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3.2 Component overview from a piston diameter of 125 mm
This diagram is intended only to provide an overview of the individual components. To order spare and wearing parts, please use the
online spare parts catalogue on the Festo website (spareparts.festo.com).
1
15
29
28
17
19
18
20
21
14
12
22
18
18
19
20
23
23
21
22
18
27
26
25
13
17
16
2
34
5
6
8
9
7
8
9
7
8
9
7
10
11
11
24
30
13
14
15
13
14
15
4
3
6
5
6
5
1

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Item Designation Note
1 Hex nut
2 Retaining ring Only with -S6
3 Piston rod seal
4 Bearing
5 Collar nut Use screw locking agent
6 Washer Only at a piston diameter of 250 mm and 320 mm
7 O-ring
8 Regulating screw
9 Serrated ring
10 Rod Only at a piston diameter of ≥ 125 mm
11 Bearing cap
12 Tie rod
13 O-ring
14 Cushioning seal
15 Retaining ring Only at a piston diameter of 125 mm, 160 mm and 200 mm
16 Piston rod
17 Cushioning boss
18 Lip ring (piston seal)
19 Piston
20 O-ring
21 Guiding band
22 Magnetic strip
23 Washer Only at a piston diameter of 250 mm and 320 mm
24 Threaded coupling Not S2, use screw locking agent
25 Piston rod Only S2, use screw locking agent?
26 Cylinder barrel
27 Trunnion mounting DNGZS only
28 Socket head screw DNGLZ and DNGZK only
29 Trunnion mounting DNGLZ and DNGZK only
30 End cap

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4 Repair steps
4.1 Preparation
• Before starting the repair, remove any attachments in accordance with the instructions in the accompanying
operating instructions.
• Keep your working environment tidy.
• Only use the spare parts and assembly aids (grease, locking agent, etc.) provided in the set of wearing parts.
Warning
Make sure that the bearing cap cannot suddenly come ying off.
• Remove the non-return valves and tubing connection from the cylinder and depressurise the cylinder completely
so that any pressure present is not suddenly released when the cylinder is opened.
To prevent damage to sealing rims or guide surfaces, do not use pointed or sharp-edged assembly aids.
4.2 Visual inspection
Check the cylinder for visible damage that might impair its function (e.g. warping of the piston rod) as well as deposits
and scoring. The entire cylinder must be replaced if the cylinder barrel is showing signs of signicant damage.
4.3 Repairing the cylinders DNG / DNGL / DNGLZ / DNGZK and DNGLZS-…
The cylinders type DNG / DNGL / DNGLZ / DNGZK and DNGLZS-… with the following features can be repaired using the
description in this chapter:
Code Description
PPV Adjustable pneumatic cushioning
A External position sensing
S2 Through piston rod
S3 Stainless steel piston rod
S8 Piston rod with high corrosion protection

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4.3.1 Structure of the bearing cap
Note
In some series and variants the bearing and end caps may differ from the versions shown here. The precise design
of the bearing and end caps must be determined before each repair using the parts lists in the online spare parts
catalogue on the Festo website (spareparts.festo.com) and taken into consideration during the repair.
Bearing cap DNG
1
2
3
4
5
6
1Bearing cap
2O-ring
3Cushioning seal
4Piston rod seal
5Bearing
4.3.2 Removing the bearing and end caps
• Loosen the collar nuts in the bearing cap from the tie rods, while holding
the collar nuts in the end cap (in the second bearing cap of cylinders with
a through piston rod (S2)).
Note
Only cylinders with a piston diameter of 250 mm and 320 mm have washers
between the collar nut and the bearing or end cap.
• Unscrew and remove the collar nuts and washers.
• Pull the bearing cap away from the cylinder barrel and piston rod.
• Onlyappliestocylinderswithapistondiameter≥125mm
– Remove the rod from the end cap (from the second bearing cap on
cylinders with a through piston rod (S2)).
• Only applies to DNGLZS
– Remove the trunnion mounting from the cylinder barrel and the tie rods.
• Only applies to DNGLZ and DNGZK
– Loosen the socket head screw in the trunnion mounting.
– Remove the trunnion mounting from the cylinder barrel and the tie rods.
• Remove the end cap from the cylinder barrel and piston rod (the second
bearing cap on cylinders with a through piston rod (S2)).
• Remove the tie rods including the collar nuts and washers (if present,
see note above) from the end cap (from the second bearing cap on cylinders
with a through piston rod (S2)) and unscrew the collar nuts from the tie rods.
• Remove any residue of the screw locking agent from the thread of the collar
nuts and tie rods.

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4.3.3 Replacing the piston components
• Pull the piston rod out of the cylinder barrel.
• Check the cylinder barrel and piston rod for damage.
The entire cylinder must be replaced if the cylinder barrel (particularly the
bearing surface) is showing signicant damage.
• Unscrew the threaded coupling (the rear part of the piston rod on cylinders
with through piston rod (S2)) from the piston rod.
• Remove the piston components from the piston rod, noting the sequence
and alignment.
• Remove any residue of the screw locking agent from the threads of the
piston rod and threaded coupling (the thread on the rear part of the piston
rod on cylinders with through piston rod (S2 )).
• Replace the components with those included in the set of wearing parts and
reassemble the piston components on the piston rod in the correct order.
• Apply the screw locking agent included in the set of wearing parts to the
inside of the threaded coupling (the rear part of the piston rod on cylinders
with through piston rod (S2)) and screw it onto the piston rod with the
corresponding torque (see table).
Type Torque
DNG / DNGL / DNGLZ / DNGZK-32 10 Nm
DNG / DNGL / DNGLZ / DNGZK-40 20 Nm
DNG / DNGL / DNGLZ / DNGZK-50 25 Nm
DNG / DNGL / DNGLZ / DNGZK-63 40 Nm
DNG / DNGL / DNGLZ / DNGZK-80 60 Nm
DNG / DNGL / DNGLZ / DNGZK-100 30 Nm
DNG / DNGZK-125 160 Nm
DNG / DNGZK-160 330 Nm
DNG / DNGZK-200 330 Nm
DNG-250 700 Nm
DNG-250-…-S2 700 Nm
DNGZS-250 700 Nm
DNG-320 1300 Nm
DNG-320-…-S2 1200 Nm
DNGZS-320 1200 Nm

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4.3.4 Inserting the piston rod into the cylinder barrel
• Clean the inner surface of the cylinder barrel as described in chapter 5.1
"Cleaning".
• Apply the grease included in the set of wearing parts to the following parts:
Component Greasing
Inner surface of cylinder barrel Thin lm1)
Surface of piston rod Thin lm1)
Piston seal lip rings Thin lm1) on outside
Piston surface between lip rings
(grease reservoir2))
Fill 2/3 with grease
Cushioning boss
Thin lm1) on outside
1) See chapter 5.2.2 "Thin grease lm"
2) See chapter 5.2.3 "Grease reservoir"
• Place the piston at on the front side of the cylinder barrel and insert the lip
ring into the cylinder barrel by tilting and turning it slightly.
The sealing lip must not fold back against the inside of the piston.
• Insert the piston fully into the cylinder barrel.
• Push the piston far enough into the cylinder barrel so that the rst lip ring
protrudes slightly at the other end of the cylinder barrel.
• Pull the piston rod back again until the piston is sitting fully in the cylinder
barrel.
Note
This approach ensures that the sealing lips of the two lip rings sit correctly in
the cylinder barrel.
4.3.5 Repairing and attaching the bearing and end caps
• Remove the piston rod seal from the bearing cap (from the front and rear
bearing caps on cylinders with through piston rod (S2)).
• Remove the O-ring from the groove of the bearing cap and end cap (the rear
bearing cap on cylinders with through piston rod (S2)).
• Only on cylinders with a piston diameter of 125 mm to 200 mm
– Remove the retaining ring upstream of the cushioning seal from
the bearing cap and end cap (from the front and rear bearing cap on
cylinders with a through piston rod (S2)).
• Remove the cushioning seal from the bearing cap and end cap (the rear
bearing cap on cylinders with through piston rod (S2)).

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Warning
Check the plain bearing in the bearing cap (in the front and rear bearing caps
on cylinders with through piston rod (S2)) for visible damage that might
impair its function, such as deposits and scoring. The entire bearing cap
must be replaced if the plain bearing is showing signi cant damage.
• Only when repairing the adjustable cushioning (PPV)
Note
Proceed as described in chapter 4.5 “Repairing the adjustable end-position
cushioning (PPV)” to repair the adjustable end-position cushioning.
• Clean the seat of the piston rod seal 1.
• Clean the seat of the O-ring 2.
• Clean the seat of the cushioning seal 3.
See chapter 5.1 "Cleaning"
1 2
3
• Grease the new piston rod seal (one per bearing cap on cylinders with
through piston rod (S2)) as follows:
Area Greasing
1Grease reservoir1) for piston rod Fill 2/3 with grease
2External surface for bearing cap Thin  lm2)
3Grease reservoir1) for bearing Fill 2/3 with grease
1) See chapter 5.2.3 "Grease reservoir"
2) See chapter 5.2.2 "Thin grease  lm" 1 2 3
• Insert the piston rod seal into the bearing cap (in both bearing caps on
cylinders with through piston rod (S2)) using an appropriate pressure piece.
Note
Note the mounting direction (individual sealing lips facing out).
• Grease the new O-rings and insert them into the grooves in the bearing cap
and end cap (the rear bearing cap on cylinders with through piston rod (S2 )).
• Apply a thin  lm of grease to the new cushioning seals on the front side
of the sealing surface and insert them into the bearing cap and end cap
(the rear bearing cap on cylinders with through piston rod (S2 )).
• Only on cylinders with a piston diameter of 125 mm to 200 mm
– Insert the new retaining ring upstream of the new cushioning seal in the
bearing cap and end cap (in the front and rear bearing cap on cylinders
with a through piston rod (S2)).

18 / 28 Festo 7DNGa_en
• Apply the screw locking agent included in the set of wearing parts to the
thread of the tie rods.
Note
Only cylinders with a piston diameter of 250 mm and 320 mm have washers
between the collar nut and the bearing or end cap.
• Place the washers on the collar nuts.
• Screw the collar nuts on one side of on the tie rods.
• Insert the tie rods including the collar nuts and washers (if present, see note
above) through the holes of the end cap (through the second bearing cap on
cylinders with a through piston rod (S2)).
• Onlyappliestocylinderswithapistondiameter≥125mm
– Insert the rod into the end cap (in the second bearing cap on cylinders
with a through piston rod (S2)).
• Push the cylinder barrel with the piston onto the end cap.
• Only applies to DNGLZS
– Push the trunnion mounting onto the cylinder barrel and the tie rods.
• Only applies to DNGLZ and DNGZK
– Push the trunnion mounting onto the cylinder barrel and the tie rods.
• To protect the bearing and seals, place the appropriate mounting sleeve
(see chapter 7.2 "Special tools") on the thread of the piston rod to prevent
damage.
• Guide the bearing cap (both bearing caps on cylinders with through
piston rod (S2)) over the mounting sleeve onto the piston rod as far as
the cylinder barrel.
Note
Only cylinders with a piston diameter of 250 mm and 320 mm have washers
between the collar nut and the bearing or end cap.
• Screw the collar nuts and washers in the bearing cap onto the tie rods,
while holding the collar nuts in the end cap (in the second bearing cap of
cylinders with a through piston rod (S2)).
• Tighten the collar nuts with the appropriate torque (see table).
Type Torque
DNG / DNGL / DNGLZ / DNGZK-32 6 Nm
DNG / DNGL / DNGLZ / DNGZK-40 6 Nm
DNG / DNGL / DNGLZ / DNGZK-50 14 Nm
DNG / DNGL / DNGLZ / DNGZK-63 14 Nm
DNG / DNGL / DNGLZ / DNGZK-80 30 Nm
DNG / DNGL / DNGLZ / DNGZK-100 30 Nm
DNG / DNGZK-125 70 Nm
DNG / DNGZK-160 100 Nm
DNG / DNGZK-200 100 Nm
DNG-250 90 Nm
DNG-250-…-S2 140 Nm
DNGZS-250 140 Nm
DNG / DNGZS-320 280 Nm

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• Only applies to DNGLZS
– Push the trunnion mounting onto the cylinder barrel and the tie rods.
• Only applies to DNGLZ and DNGZK
– Push the trunnion mounting onto the cylinder barrel and the tie rods.
– Tighten the socket head screw in the trunnion mounting using the
appropriate torque (see table).
Type Torque
DNGLZ / DNGZK-32 4 Nm
DNGLZ / DNGZK-40 6 Nm
DNGLZ-50 9 Nm
DNGZK-50 8 Nm
DNGLZ / DNGZK-63 12 Nm
DNGLZ / DNGZK-80 8 Nm
DNGLZ / DNGZK-100 8 Nm
DNGZK-125 14 Nm
DNGZK-160 15 Nm
DNGZK-200 22 Nm
• Perform a functional test as per the operating instructions (enclosed with
the cylinder or can be called up on the Festo website (www.Festo.com)) and
commission the repaired cylinder.
4.4 Repairing the cylinders DNG / DNGL / DNGLZ / DNGZK / DNGLZS-…-S6
Cylinders type DNG / DNGL / DNGLZ / DNGZK / DNGLZS-…-S6 with the following features can be repaired by following
the description in this chapter:
DNG/DNGL/ DNGLZ / DNGZK / DNGLZS
Code Description
PPV Adjustable pneumatic cushioning
A External position sensing
S3 Stainless steel piston rod
S8 Piston rod with high-level of corrosion protection
4.4.1 Structure of the bearing cap
Note
In some series and variants the bearing and end caps may differ from the versions shown here. The precise design
of the bearing and end caps must be determined before each repair using the parts lists in the online spare parts
catalogue on the Festo website (spareparts.festo.com) and taken into consideration during the repair.
Bearing cap DNG-...-S6
1
2
3
4
6
5
7
1Bearing cap
2O-ring
3Cushioning seal
4Piston rod seal
5Retaining ring
6Bearing

20 / 28 Festo 7DNGa_en
4.4.2 Removing the bearing and end caps
• Loosen the collar nuts in the bearing cap from the tie rods, while holding the
collar nut in the end cap.
Note
Only cylinders with a piston diameter of 250 mm and 320 mm have washers
between the collar nut and the bearing or end cap.
• Unscrew and remove the collar nuts and washers.
• Pull the bearing cap away from the cylinder barrel and piston rod.
• Onlyappliestocylinderswithapistondiameter≥125mm
– Remove the rod from the end cap.
• Only applies to DNGLZS
– Remove the trunnion mounting from the cylinder barrel and the tie rods.
• Only applies to DNGLZ and DNGZK
– Loosen the socket head screw in the trunnion mounting.
– Remove the trunnion mounting from the cylinder barrel and the tie rods.
• Remove the end cap from the cylinder barrel and the piston rod.
• Remove the tie rods including the collar nuts and washers (if present,
see note above) from the end cap and unscrew the collar nuts from the
tie rods.
• Remove any residue of the screw locking agent from the thread of the collar
nuts and tie rods.
4.4.3 Replacing the piston components
• Pull the piston rod out of the cylinder barrel.
• Check the cylinder barrel and piston rod for damage.
The entire cylinder must be replaced if the cylinder barrel (particularly the
bearing surface) is showing signicant damage.
• Unscrew the threaded coupling from the piston rod.
• Remove the piston components from the piston rod, noting the sequence
and alignment.
• Remove any residue of the screw locking agent from the threads of the
piston rod and threaded coupling.
• Replace the components with those included in the set of wearing parts and
reassemble the piston components on the piston rod in the correct order.