GEM 8253 User manual

GEMÜ 8253
Electrically operated solenoid valve
Operating instructions
EN
further information
webcode: GW-8253

All rights including copyrights or industrial property rights are expressly reserved.
Keep the document for future reference.
© GEMÜ Gebr. Müller Apparatebau GmbH & Co. KG
10.06.2022
www.gemu-group.com2 / 20GEMÜ 8253

Contents
1 Allgemeines ......................................................... 4
1.1 Hinweise ................................................... 4
1.2 Symbols used ........................................... 4
1.3 Begriffsbestimmungen ............................. 4
1.4 Warning notes ........................................... 4
2 Safety information ............................................... 5
3 Product description ............................................. 5
3.1 Aufbau ...................................................... 5
3.2 Function .................................................... 5
4 Correct use .......................................................... 6
5 Order data ........................................................... 7
5.1 Order codes .............................................. 7
5.1.1 Type ............................................. 7
5.1.2 DN ................................................ 7
5.1.3 Body configuration ........................ 7
5.1.4 Connection ................................... 7
5.1.5 Valve body material ...................... 7
5.1.6 Seal material ................................. 7
5.1.7 Control function ............................ 7
5.1.8 Supply voltage .............................. 7
5.1.9 Mains frequency ........................... 7
5.1.10 Special function ............................ 7
5.2 Order example .......................................... 7
6 Dimensions .......................................................... 9
7 Manufacturer's information .................................. 10
7.1 Delivery .................................................... 10
7.2 Transport .................................................. 10
7.3 Storage ..................................................... 10
8 Installation and operation .................................... 10
8.1 Installation ................................................ 10
9 Electrical connection ........................................... 11
10 Commissioning .................................................... 12
11 Inspection and maintenance ................................ 12
11.1 Inspection ................................................. 12
11.2 Cleaning ................................................... 12
11.3 Solenoid coil replacement ......................... 12
11.4 Armature replacement .............................. 13
11.5 Diaphragm replacement ............................ 13
12 Troubleshooting .................................................. 14
13 Disposal .............................................................. 14
14 Returns ................................................................ 14
15 Information .......................................................... 14
16 Declaration of conformity according to 2014/68/
EC (Pressure Equipment Directive) ...................... 14
17 EU Declaration of Conformity ............................... 15
GEMÜ 8253www.gemu-group.com 3 / 20

www.gemu-group.com4 / 20GEMÜ 8253
1 Allgemeines
1 Allgemeines
1.1 Hinweise
- The descriptions and instructions apply to the standard ver-
sions. For special versions not described in this document
the basic information contained herein applies in combina-
tion with any additional special documentation.
- Correct installation, operation, maintenance and repair work
ensure faultless operation of the product.
- Should there be any doubts or misunderstandings, the Ger-
man version is the authoritative document.
- Contact us at the address on the last page for staff training
information.
1.2 Symbols used
The following symbols are used in this document:
Symbol Meaning
Tasks to be performed
Response(s) to tasks
– Lists
1.3 Begriffsbestimmungen
Working medium
The medium that flows through the GEMÜ product.
1.4 Warning notes
Wherever possible, warning notes are organised according to
the following scheme:
SIGNAL WORD
Type and source of the danger
Possible
symbol for the
specific
danger
Possible consequences of non-observance.
Measures for avoiding danger.
Warning notes are always marked with a signal word and
sometimes also with a symbol for the specific danger.
The following signal words and danger levels are used:
DANGER
Imminent danger!
▶Non-observance can cause death or
severe injury.
WARNING
Potentially dangerous situation!
▶Non-observance can cause death or
severe injury.
CAUTION
Potentially dangerous situation!
▶Non-observance can cause moderate
to light injury.
NOTICE
Potentially dangerous situation!
▶Non-observance can cause damage to
property.
The following symbols for the specific dangers can be used
within a warning note:
Symbol Meaning
Danger – high voltage
Danger - hot surfaces

www.gemu-group.com 5 / 20 GEMÜ 8253
2 Safety information
The safety information in this document refers only to an indi-
vidual product. Potentially dangerous conditions can arise in
combination with other plant components, which need to be
considered on the basis of a risk analysis. The operator is re-
sponsible for the production of the risk analysis and for com-
pliance with the resulting precautionary measures and re-
gional safety regulations.
The document contains fundamental safety information that
must be observed during commissioning, operation and main-
tenance. Non-compliance with these instructions may cause:
- Personal hazard due to electrical, mechanical and chemical
effects.
- Hazard to nearby equipment.
- Failure of important functions.
- Hazard to the environment due to the leakage of dangerous
materials.
The safety information does not take into account:
- Unexpected incidents and events, which may occur during
installation, operation and maintenance.
- Local safety regulations which must be adhered to by the
operator and by any additional installation personnel.
Prior to commissioning:
1. Transport and store the product correctly.
2. Do not paint the bolts and plastic parts of the product.
3. Carry out installation and commissioning using trained
personnel.
4. Provide adequate training for installation and operating
personnel.
5. Ensure that the contents of the document have been fully
understood by the responsible personnel.
6. Define the areas of responsibility.
7. Observe the safety data sheets.
8. Observe the safety regulations for the media used.
During operation:
9. Keep this document available at the place of use.
10. Observe the safety information.
11. Operate the product in accordance with this document.
12. Operate the product in accordance with the specifications.
13. Maintain the product correctly.
14. Do not carry out any maintenance work and repairs not de-
scribed in this document without consulting the manufac-
turer first.
In cases of uncertainty:
15. Consult the nearest GEMÜ sales office.
3 Product description
3.1 Aufbau
1
2
3
Item Name Materials
1 Plug PA
2 Coil Duresco NU 463V
3 Valve body CW617N (brass)
1.4408, stainless steel
Seal material EPDM, NBR, FKM
3.2 Function
1
705
704
*103
2
4
3
Fig.1: Functional description (NC)
Switch position closed
The compression spring 704 in the armature 705 closes the
pilot seat 1. The diaphragm *103 is pushed down onto the
main valve seat 4 by a closing spring2. The medium flows
through the control aperture 3 in the diaphragm into the con-
trol chamber above the diaphragm and thus increases the
closing force.
Switch position open:
3 Product description

www.gemu-group.com6 / 20GEMÜ 8253
4 Correct use
When voltage is applied, the armature 705 is attracted to the
pole surface of the bush. The pressure of the medium from
the control chamber reduces towards the valve outlet through
the open pilot seat 1. More medium flows away through the
pilot seat 1 than can flow in through the control aperture 3 in
the diaphragm. The differential pressure produced lifts the
diaphragm *103 thus opening the main valve seat 4.
All the parts marked * are included in the wearing parts kit.
When ordering spare parts, please state the complete valve
order number.
Switch position open
The compression spring 704 in the armature 705 opens the
pilot seat 1. The pressure of the medium from the control
chamber above diaphragm *103 reduces towards the valve
outlet through the open pilot seat 1.
More medium flows away from the control chamber through
the pilot seat than can flow in through the control aperture 3
in the diaphragm. The differential pressure produced lifts the
diaphragm thus opening the main valve seat 4.
Switch position closed
When voltage is applied the pilot seat 1 is closed by the arma-
ture705. The medium flows through the control aperture 3 in
the diaphragm *103 into the control chamber above the dia-
phragm and moves the diaphragm into the closed position
supported by the spring. The operating pressure increases the
closing force.
All the parts marked * are included in the wearing parts kit.
When ordering spare parts, please state the complete valve
order number.
4 Correct use
DANGER
Danger of explosion!
▶Risk of severe injury or death.
●Do not use the product in potentially
explosive zones.
●Only use the product in potentially ex-
plosive zones confirmed in the declara-
tion of conformity.
WARNING
Improper use of the product
▶Risk of severe injury or death.
▶Manufacturer liability and guarantee will be void.
●Only use the product in accordance with the operating
conditions specified in the contract documentation and in
this document.
The product is designed for installation in piping systems and
for controlling a working medium.
1. Use the product in accordance with the technical data.
2. Note the supplement acc. to ATEX
3. Please note the flow direction on the valve body.

5 Order data
The order data provide an overview of standard configurations.
Please check the availability before ordering. Other configurations available on request.
Order codes
1 Type Code
Solenoid valve, with positive lift diaphragm 8253
2 DN Code
DN 8 8
DN 10 10
DN 15 15
DN 20 20
DN 25 25
DN 32 32
DN 40 40
DN 50 50
3 Body configuration Code
2/2-way body D
4 Connection type Code
Threaded socket DIN ISO 228 1
Threaded socket NPT 31
5 Valve body material Code
CW617N (brass) 12
1.4408, stainless steel 37
6 Seal material Code
NBR 2
FKM 4
EPDM 14
7 Control function Code
Normally closed (NC) 1
Normally open (NO) 2
8 Voltage Code
24 V 24
110 V 110
230 V 230
9 Frequency Code
DC DC
50 - 60 Hz 50/60
10 Special version Code
Without
ATEX version X
Order example
Ordering option Code Description
1 Type 8253 Solenoid valve, with positive lift diaphragm
2 DN 25 DN 25
3 Body configuration D 2/2-way body
4 Connection type 1 Threaded socket DIN ISO 228
5 Valve body material 12 CW617N (brass)
6 Seal material 2 NBR
7 Control function 1 Normally closed (NC)
8 Voltage 230 230 V
9 Frequency 50/60 50 - 60 Hz
10 Special version Without
5 Order data
www.gemu-group.com 7 / 20 GEMÜ 8253

www.gemu-group.com8 / 20GEMÜ 8253
5 Order data

6 Dimensions
R
T
L1
L
H1
H
26,5
49,5
ØA
48,5 x 42
L
ØA
H1
H
R
T
L1
41
83
80 x 74
DN 8 - 25 DN 32 - 50
DN Connection type code 1)
1, 31 1 31
A H H1 L L1 R T R T
844.0 104.0 92.5 60.0 27.5 G 1/4 12.0 1/4” NPT 10.0
10 44.0 104.0 92.5 60.0 27.5 G 3/8 12.0 3/8” NPT 10.5
15 44.0 108.0 94.5 67.0 31.0 G 1/2 14.0 1/2” NPT 13.5
20 50.0 115.0 99.0 80.0 36.5 G 3/4 16.0 3/4” NPT 14.0
25 62.0 124.0 103.5 95.0 44.0 G 1 18.0 1” NPT 17.0
32 92.0 186.0 157.0 132.0 60.0 G 1¼ 20.0 1¼” NPT 17.0
40 92.0 186.0 157.0 132.0 60.0 G 1½ 22.0 1½” NPT 17.0
50 109.0 201.5 167.0 160.0 74.0 G 2 24.0 2” NPT 17.5
Dimensions in mm
1) Connection type
Code 1: Threaded socket DIN ISO 228
Code 31: Threaded socket NPT
GEMÜ 8253www.gemu-group.com 9 / 20
6 Dimensions

www.gemu-group.com10 / 20GEMÜ 8253
7 Manufacturer's information
7 Manufacturer's information
7.1 Delivery
●Check that all parts are present and check for any damage
immediately upon receipt.
The product's performance is tested at the factory. The scope
of delivery is apparent from the dispatch documents and the
design from the order number.
7.2 Transport
1. Only transport the product by suitable means. Do not drop.
Handle carefully.
2. After the installation dispose of transport packaging ma-
terial according to relevant local or national disposal regu-
lations / environmental protection laws.
7.3 Storage
1. Store the product free from dust and moisture in its ori-
ginal packaging.
2. Avoid UV rays and direct sunlight.
3. Do not exceed the maximum storage temperature (see
chapter "Technical data").
4. Do not store solvents, chemicals, acids, fuels or similar
fluids in the same room as GEMÜ products and their spare
parts.
8 Installation and operation
CAUTION
Functional impairment of the solenoid valve by contamin-
ated media!
▶The solenoid valve will cease to open or close if the con-
trol apertures are blocked or if the armature is blocked by
dirt.
●The piping system should be cleaned before installing the
solenoid valve.
●Fit a strainer with a mesh size of ≤ 0.25 mm in front of the
valve inlet if the media are contaminated.
●Switch the solenoid valve at least once a month.
CAUTION
Destruction of the solenoid valve by freezable medium!
▶The solenoid valve is not frost-protected.
●Solenoid valves using freezable media should only be op-
erated above freezing point.
CAUTION
Danger from flow contrary to flow direction!
▶Damage to the solenoid valve.
●Only operate the solenoid valve in flow direction.
●Take precautionary measures in case of expected reverse
flow (e.g. check valve).
8.1 Installation
CAUTION
Do not use the solenoid coil as a lever
▶If the solenoid coil is used as a lever, the solenoid coil
and bush could be destroyed.
●Use only the spanner flats provided to screw the solenoid
valve to the piping.
CAUTION
Damage to the valve body
●The solenoid valve may only be installed in aligned pipes
in order to avoid stresses in the valve body.

www.gemu-group.com 11 / 20 GEMÜ 8253
Fig.2: Installing the solenoid valve
1. Clean the piping system before installing the valve.
2. If necessary, fit a strainer in front of the valve inlet.
3. Remove the protection caps from the valve inlet and valve
outlet.
4. Screw the solenoid valve onto the pipeline according to
the direction of flow and seal with a suitable sealant.
5. Use the spanner flat to screw it on.
9 Electrical connection
NOTICE
Important:
▶A plug with an integrated bridge rectifier must be used for
the AC design.
DANGER
Risk of electric shock
▶Risk of injury or death (if operating
voltage is higher than safe extra low
voltage).
▶Electric shock can cause severe burns
and fatal injury.
●Work on electrical connections only by
qualified trained personnel.
●Disconnect the cable from the power
supply before making the electrical
connection.
●Connect the protective earth con-
ductor.
5
4
3
2
1
Fig.3: Inserting the cable
1. Remove the cable gland 1 and fixing screw 5.
2. Guide the cable through the cable gland 1, washer 2, rub-
ber sleeve 3 and then through the plug housing 4.
3. Connect the cable.
12
Fig.4: Connection to the terminal block
Item Connection
1 Supply voltage
2 Supply voltage
Protective earth conductor
4. Connect the cable to the relevant terminals on the terminal
block.
5. Push the terminal block into the housing of the plug until it
audibly clicks in position.
6. Tighten the locking screw on the plug.
Mounting the plug
7. Push the rubber sleeve 3 and washer 2 into the plug hous-
ing 4.
8. Tighten the cable gland 1.
9. Push the plug onto the mount.
10. Fix the plug with the fixing screw 5.
ðThe plug is mounted.
9 Electrical connection

www.gemu-group.com12 / 20GEMÜ 8253
10 Commissioning
10 Commissioning
CAUTION
Foreign matter
▶Damage to the valves.
●If the plant is new and after repairs, rinse the piping sys-
tem with the valves fully open.
ðThe plant operator is responsible for selecting the clean-
ing material and performing the procedure.
1. Make sure that the unit is installed properly.
2. Test the function of the solenoid valve.
3. Check the tightness of the media connections and the
solenoid valve itself.
4. Fill the solenoid valve slowly with medium.
11 Inspection and maintenance
WARNING
Danger of burning from hot surfaces!
▶Solenoid coil heats up during opera-
tion.
●Allow the solenoid coil and piping to
cool down before servicing work.
Preventive maintenance / cleaning is recommended in con-
sideration of the operating conditions and in the event of no-
ticeable changes in switching times or noise arising during
switching.
All the parts marked * are included in the wearing parts kit.
When ordering spare parts, please state the complete valve
order number.
11.1 Inspection
Check the solenoid coil at regular intervals, depending upon
the ambient conditions, for cracks and deposits of dirt and
check the plug for secure location and good sealing.
The operator is responsible for determining appropriate in-
spection intervals.
11.2 Cleaning
CAUTION
Foreign matter
▶Damage to the valves.
●If the plant is new and after repairs, rinse the piping sys-
tem with the valves fully open.
ðThe plant operator is responsible for selecting the clean-
ing material and performing the procedure.
11.3 Solenoid coil replacement
5
4
6
400
706
701
*707
Fig.5: Solenoid coil replacement
1. Disconnect the plug 4 from power supply.
2. Remove the fixing screw 5.
3. Pull the plug 4 and gasket 6 off the solenoid coil 400.
4. Disengage the spring clip 706 and pull the solenoid coil
400 off the bush 701.
5. Check the O-ring *707 701on the bush 701 for hardening
and replace if necessary.
6. Place a new solenoid coil on the bush and engage the
spring clip.
7. Push the plug and gasket onto the solenoid coil and
tighten with the fixing screw (60 Ncm).

www.gemu-group.com 13 / 20 GEMÜ 8253
11.4 Armature replacement
WARNING
Danger from medium spurting out!
▶Danger of injury.
●Servicing work on the solenoid valve
should only be carried out after the pip-
ing has been depressurized and
drained!
*702
*705
*704
706 701
7
400
Fig.6: Armature replacement
1. Release the pressure from the solenoid valve and from the
piping and drain off.
2. Disconnect the solenoid coil from power supply.
3. Disengage the spring clip 706 and pull the solenoid coil
400 off the bush 701.
4. Unscrew the bush 701 with threaded insert 7 (SW22) and
remove it.
5. Take O-ring *702 out of groove.
6. Replace O-ring *702, compression spring *704 and arma-
ture *705.
7. Screw in bush 7 with threaded insert (20 Nm ± 10 %).
8. Place the solenoid coil on the bush and engage the spring
clip.
11.5 Diaphragm replacement
WARNING
Danger from medium spurting out!
▶Danger of injury.
●Servicing work on the solenoid valve
should only be carried out after the pip-
ing has been depressurized and
drained!
*103
*105
102
104
706
400
Fig.7: Diaphragm replacement
1. Release the pressure from the solenoid valve and from the
piping and drain off.
2. Disconnect the solenoid coil 400 from power supply.
3. Disengage the spring clip 706 and pull the solenoid coil
400 off the bush.
4. Remove cover screws 104 and remove valve cover 102.
5. Replace diaphragm *103 and compression spring *105.
6. Place the valve cover on the valve body and tighten with
the cover screws diagonally.
Tightening torque for the cover screws:
Thread Torque
M4 2.0 Nm ± 10 %
M5 3.6 Nm ± 10 %
M6 6.0 Nm ± 10 %
M8 16.0 Nm ± 10 %
M10 31.0 Nm ± 10 %
11 Inspection and maintenance

www.gemu-group.com14 / 20GEMÜ 8253
12 Troubleshooting
12 Troubleshooting
Error Error cause Troubleshooting
No function No power supply Check power sup-
ply and connection
with product label
Solenoid coil faulty Replace solenoid
valve
Operating pressure
too high
Check operating
pressure, reduce if
necessary
Diaphragm faulty Replace diaphragm
Control aperture
contaminated
Clean solenoid
valve, fit strainer in
front if necessary
Armature blocked Clean the armature
and bush, replace
the armature if ne-
cessary
Valve does not
switch
Use a plug with an
integrated bridge
rectifier (for AC
design)
Solenoid valve leak-
ing
Main valve seat
leaking
Clean main valve
seat, replace dia-
phragm if neces-
sary
13 Disposal
1. Pay attention to adhered residual material and gas diffu-
sion from penetrated media.
2. Dispose of all parts in accordance with the disposal regu-
lations/environmental protection laws.
Parts Disposal
Valve bodies, valve covers in accordance with material
identification
Screws, armatures, bushes,
compression springs
as metallic core scrap
O-rings, diaphragms, sealing
and plastic parts
as domestic waste type com-
mercial waste
Solenoid coil as electrical scrap
14 Returns
Legal regulations for the protection of the environment and
personnel require that the completed and signed return deliv-
ery note is included with the dispatch documents. Returned
goods can be processed only when this note is completed. If
no return delivery note is included with the GEMÜ product,
GEMÜ cannot process credits or repair work but will dispose
of the goods at the operator's expense.
1. Clean the GEMÜ 8253 .
2. Request a return delivery note from GEMÜ.
3. Complete the return delivery note.
4. Send the GEMÜ 8253 with a completed return delivery
note to GEMÜ.
15 Information
NOTICE
Note on staff training:
▶Please contact us at the address on the last page for
staff training information.
Should there be any doubts or misunderstandings in the pre-
ceding text, the German version of this document is the au-
thoritative document!
16 Declaration of conformity according to 2014/68/
EC (Pressure Equipment Directive)
We, GEMÜ Gebr. Müller Apparatebau
GmbH & Co. KG
Fritz-Müller-Straße 6-8
74653 Ingelfingen-Criesbach, Ger-
many
declare that the product listed below complies with the safety
requirements of the Pressure Equipment Directive 2014/68/
EU.
Description of the pres-
sure equipment:
GEMÜ 8253
Notified body: TÜV Rheinland Industrie Service
GmbH
Number: 0035
Certificate no.: 01 202 926/Q-02 0036
Conformity assessment
procedure:
Module H1
Technical standard used: EN 1983, AD 2000
Note for products with a nominal size ≤ DN 25:
The products are developed and produced according to
GEMÜ process instructions and quality standards which com-
ply with the requirements of ISO 9001 and ISO 14001.
According to Article 4, Paragraph 3 of the Pressure Equipment
Directive 2014/68/EU these products must not be identified
by a CE-label.
Joachim Brien
Head of Technical Department
Ingelfingen-Criesbach

www.gemu-group.com 15 / 20 GEMÜ 8253
17 EU Declaration of Conformity
We, GEMÜ Gebr. Müller Apparatebau
GmbH & Co. KG
Fritz-Müller-Straße 6-8
74653 Ingelfingen-Criesbach, Ger-
many
declare that the product listed below complies with the follow-
ing directives:
• Low Voltage Directive 2014/35/EU
• EMC Directive 2014/30/EU
Product: GEMÜ 8253
Ensure compliance with the limiting values of the harmonised
standards EN61000-6-3 and EN61000-6-2 and thus meeting
the requirements of the Electromagnetic compatibility direct-
ive 2014/30/EU (2004/108/EC) by suitable electrical wiring of
the solenoid valves.
Joachim Brien
Head of Technical Department
Ingelfingen-Criesbach
17 EU Declaration of Conformity

www.gemu-group.com16 / 20GEMÜ 8253
17 EU Declaration of Conformity

www.gemu-group.com17 / 20GEMÜ 8253

www.gemu-group.com18 / 20GEMÜ 8253

www.gemu-group.com 19 / 20 GEMÜ 8253

GEMÜ Gebr. Müller Apparatebau GmbH & Co. KG
Fritz-Müller-Straße 6-8, 74653 Ingelfingen-Criesbach, Germany
Phone [phone] · [email protected]
www.gemu-group.com
Subject to alteration
06.2022