Pfeiffer Vacuum MVP 035-2 User manual

Betriebsanleitung • Operating Instructions
PU 0011 BE/J (0609)
Diaphragm Pumps
MVP 035-2
MVP 055-3
MVP 055-3C

2
Index
Index
1 About this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Validity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Proper use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3 Improper use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Transport and storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4 Product description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1 Product identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4.2 Design and function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1 Setting up the pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2 Connecting the vacuum side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.3 Connecting the exhaust side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.4 Connecting to the mains power supply . . . . . . . . . . . . . . . . . . . . . 11
5.5 Retrofitting the gas ballast valve . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.1 Before switching on the pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.2 Switching on the pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.3 Pumping condensable vapors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.4 Switching off the pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.1 Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.2 Cleaning and replacing diaphragm and valves at MVP 035-2 . . . . 18
7.3 Cleaning and replacing diaphragm and valves at MVP 055-3 . . . . 20
7.4 Cleaning and replacing diaphragm and valves at MVP 055-3C . . . 24
8 Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
8.1 Shutting down for longer periods . . . . . . . . . . . . . . . . . . . . . . . . . . 26
9 Malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
9.1 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10 Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
11 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
12 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
13 Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
13.1 Substances in contact with the media . . . . . . . . . . . . . . . . . . . . . . 32
13.2 Dimension diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3
About this manual
1 About this manual
1.1 Validity
This operating manual is for customers of Pfeiffer Vacuum. It describes the func-
tioning of the designated product and provides the most important information for
safe use of the unit. The description follows applicable EU guidelines. All informa-
tion provided in this operating manual refer to the current state of the product's de-
velopment. The documentation remains valid as long as the customer does not
make any changes to the product.
Up-to-date operating instructions can also be downloaded from
www.pfeiffer-vacuum.net.
1.2 Conventions
Safety instructions The safety instructions in Pfeiffer Vacuum operating manuals are the result of risk
evaluations and hazard analyses and are oriented on international certification
standards as specified by UL, CSA, ANSI Z-535, Semi-S1, ISO 3864 and DIN 4844.
In this document, the following hazard levels and information are considered:
Pictograph definiti-
ons
DANGER
Immediate danger
Death or very severe injuries occur.
WARNING
Possible danger
Death or injuries may occur.
CAUTION
Possible danger
Medium to slight injuries may occur.
NOTE
Command or note
Command to perform an action or information about properties, the disregarding of
which may result in damage to the product.
Prohibition of an action or activity in connection with a
source of danger, the disregarding of which may result in
serious accidents.
Warning of a displayed source of danger in connection
with operation of the unit or equipment.

4
Safety
Instructions in the
text
ÎWork instruction: here you have to do something.
Abbreviations used C version: Corrosive gas version
Symbols used The following symbols are used consistently throughout in all illustrations:
Vacuum connection
Exhaust
Gas ballast valve
Power connection
2 Safety
2.1 Safety precautions
• Before pumping dangerous, corrosive or environmentally hazardous media,
take suitable precautions:
– Test the compatibility with substances in contact with the media.
– Prevent the release of process gases and their reaction products and by-pro-
ducts or dispose of them according to the relevant regulations.
– Safety measures (e.g. wearing protective clothing and safety goggles) to pre-
vent inhalation and skin contact.
• Before pumping gases which could form ignitable mixtures, take suitable pre-
cautions:
– By implementing the required safety measures, prevent potentially explosive
mixtures from occurring in the housing and from being ignited in the event of
a diaphragm crack by mechanically produced sparks, hot surfaces or static
electricity.
– If necessary, use inert gas for gas ballast supply or ventilation.
• Connect the vacuum pump to a shockproof socket only.
Command to perform an action or task associated with a
source of danger, the disregarding of which may result in
serious accidents.
Important information about a product, handling or
applicable part of the documentation to which special
attention should be paid.
☞
V
G
NOTE
Duty to inform
Each person involved in the installation, operation or maintenance of the vacuum
pump must read and observe the safety-related parts of these operating instructions.
ÎThe operator is obligated to make operating personnel aware of dangers originating
from the vacuum pump, the pumped medium and the entire system.

5
Safety
– Use only undamaged network cables which comply with the regulations.
– Make sure that the grounding is neither faulty nor insufficient.
• Do not expose any body parts to the vacuum.
• Observe the safety and accident prevention regulations.
• Check regularly that all safety precautions are being complied with.
• Do not carry out any unauthorised modifications or conversions to the pumps.
• Depending on the operating and ambient conditions, the surface temperature of
the pumps may rise above 70°C. Use suitable finger guards if necessary.
• When returning the pump to us please note the instructions in the Service sec-
tion.
2.2 Proper use
• The vacuum pump may only be used to generate a vacuum.
• Installation, operating and maintenance regulations must be complied with.
• Using accessories not mentioned in this manual is not permitted without autho-
risation from Pfeiffer Vacuum.
• When pumping gases which could form explosive or ignitable mixtures, take
suitable precautions:
– If necessary, connect inert gas for ventilation or gas ballast supply.
2.3 Improper use
The following are classed as improper use:
Use for purposes which deviate from those described above, in particular:
• Pumping of corrosive gases (with exception of corrosiv gas versions).
• Pumping of explosive media.
• Operation of the pump in potentially explosive areas.
• Pumping of gases containing impurities such as particles, dusts and condensate;
note the vapour compatibility levels of the pump.
• Pumping of substances that tend to sublime.
• Use of the vacuum pump to generate pressure.
• Pumping of liquids.
• Connection to pumps or units which are not suitable for this purpose according
to their operating instructions.
• Connection to units which have touchable and voltage carrying parts.
Improper use of the equipment automatically invalidates all warranty and liability
claims.
NOTE
CE conformity
The manufacturer's declaration of conformity becomes invalid if the operator modifies
the original product or installs additional components.
ÎFollowing installation into a plant and before commissioning, the operator must
check the entire system for compliance with the valid EU directives and reassess it
accordingly.

6
Transport and storage
3 Transport and storage
3.1 Transport
Transport instructions
ÎRemove the locking cap from the vacuum flange immediately before connec-
ting!
ÎUse only the handles provided for that purpose to lift the pump.
– Do not use the interhead connections on the top side of the pump to carry the
pump.
Fig. 1: Lifting and transporting the pump
3.2 Storage
ÎCheck that all the openings on the pump are securely closed.
ÎStore the pump in a cool, dry place; preferably at room temperatures (approx.
20°C).
– For a longer period of storage, seal the pump in a PE bag with drying agents
enclosed.

7
Product description
4 Product description
4.1 Product identification
To correctly identify the product when communicating with Pfeiffer Vacuum, al-
ways have the information from the rating plate available and use it:
• Pump model and model number
• Serial number
• Date of manufacture
Please find the voltage range and motor-related data on the separately attached
motor rating plate if necessary.
Scope of delivery • Pump with mains power supply (switchable) via rubber socket
• Locking caps for vacuum and exhaust flange
• Operating manual
Differences between
the pump types Pump type Pump designs
MVP 035-2
Standard version:
• G 1/4" elbow union + enclosed hose DN 8 x 1000 mm with a elbow union
in G 1/4" at the end
MVP 055-3
Standard version:
• G 1/4" elbow union + enclosed hose DN 8 x 1000 mm with a elbow union
in G 1/4" at the end
G 1/4" elbow union + enclosed hose DN 8 x 1000 mm with a elbow union in
G 1/4" at the end
•DN16ISO-KF
MVP 055-3C C version:
• DN 16 ISO-KF / 1/8" NPT

8
Product description
4.2 Design and function
The diaphragm vacuum pumps of the series MVP 055-3/3C are three stage and
those of the MVP 035-2 series are two stage, dry compressor vacuum pumps. That
means that the supplied medium is not brought into contact with lubrication. The
pumps are positive displacement pumps with a periodic change of size of the suc-
tion chamber produced by the movement of the diaphragm. The gas flow causes
the valves to open and close automatically. The pump units are directly connected
to the drive motor.
Fig. 2: MVP 035-2
Fig. 3: MVP 055-3
A1 Vacuum connection
2.1 Exhaust (with silencer)
A Diaphragm head 1
B Diaphragm head 2
E Mains power supply
NPowerswitch
K Capacitor
U Voltage selector switch
23 Hose connection
40 Gas ballast valve
A1 Vacuum connection
2.1 Exhaust (with silencer)
A Diaphragm head 1
B Diaphragm head 2
C Diaphragm head 3
D Diaphragm head 4
E Mains power supply
N Power switch
U Voltage selector switch
23 Hose connection
40 N U (E) 2.1
K A1 A 23 B
B 2.1 U N A1
C 23 D E A

9
Product description
Fig. 4: MVP 055-3C
A1 Vacuum connection
2.1 Exhaust
A Diaphragm head 1
B Diaphragm head 2
C Diaphragm head 3
D Diaphragm head 4
E Mains power supply
N Power switch
U Voltage selector switch
28 Hose connection
40 Gas ballast valve
40 28 B U N A1
C D 2.1 E A

10
Installation
5Installation
5.1 Setting up the pump
Installation location Observe the following requirements when setting up the pump:
• Note the load-bearing capacity of the mounting surface.
• Maximum installation altitude 2000 m (above mean sea level)
• Permissible ambient temperature: +12 ... +40°C
• Maximum relative humidity 85%
ÎAlways place the pump on a firm, even surface.
– Where stationary installation is involved, anchor the pump on site.
ÎWhen installing the pump in a closed housing, ensure there is sufficient air cir-
culation.
– Voltage and frequency information given on the motor rating plate must be
visible.
– If vacuum pump is installed above 1000 m above mean sea level check com-
patibillity with applicable safety requirements, e.g. DIN EN 61010 (motor may
overheat due to insufficient cooling).
ÎCheck the hose connections between the individual pumping stages.
– The intake connections of the pumps are marked "IN" and the outlets "Ex" at
the diaphragm heads.
5.2 Connecting the vacuum side
ÎRemove locking cap on intake connection and connect vacuum pump to the ap-
paratus.
ÎThe connection between the pump and the recipient should be kept as short as
possible.
– Depending on the pump type, use metallic hoses or PVC hoses with flange
connections.
– Separators, filters etc. may be installed upstream to protect the pump (see ac-
cessories). However, please observe the loss of pumping capacity due to the
conductivity of the accessories.
5.3 Connecting the exhaust side
ÎChoose the cross-section of the exhaust line to be at least the size of the nominal
connection diameter of the vacuum pump's exhaust connection.
ÎPiping to the pump must be suspended or supported.
– Forces from the piping system must not be allowed to act on vacuum pumps.
ÎLay piping from the pump, sloping downward so that no condensate can flow
back into the pump; otherwise fit a condensate separator.
CAUTION
High pressure in the exhaust line!
Danger of damage to the seals and danger of the pump bursting.
ÎInstall the line without shut-off valves on the exhaust side.
ÎPumpe nicht mit Überdruck am Einlass betreiben; max. zulässige Drücke und Druck-
differenzen beachten.

11
Installation
5.4 Connecting to the mains power supply
The pump is driven by single-phase extended voltage range motors with reversible
voltage ranges:
• 230 V range: 200 ... 240 V, 50/60 Hz
• 115 V range: 100 ... 120 V, 50/60 Hz
Single-phase exten-
ded range motor
ÎThe mains voltage must be determined on-site each time before the pump is in-
stalled or moved to a different location.
Changing the voltage range
ÎDisconnect the pump from the power supply.
ÎSet the desired voltage range on the voltage selector switch using a suitable
screwdriver.
WARNING
Emission of toxic substances from the exhaust!
Danger of poisoning from emitted gases or vapours, which can be detrimental to
health and/or can pollute the environment, depending on the particular application.
ÎComply with the applicable regulations when working with toxic substances.
ÎOnly officially approved filter systems may be used to separate out these
substances.
CAUTION
Excess voltage!
Danger of destroying the motor.
ÎPower connections must comply with local regulations. Voltage and frequency infor-
mation given on the motor rating plate must correspond to the mains voltage and
frequency values.
ÎTo protect the motor and supply cable in case of malfunction, mains fuse protection
must be implemented.
NOTE
Overvoltage!
An incorrect voltage range setting can damage the motor.
ÎDisconnect the pump from the power supply.
ÎOnly change the voltage range on the pump when it is disconnected from the power
mains.

12
Installation
Motor protection
A self-locking thermal winding protector switches off the pump motor in the event
of overheating.
ÎAllow the pump to cool off several minutes and do not switch it back on until it
has cooled off.
Intermittend opera-
tion with TC 600 via
relay box (accessory)
Connection of diaphragm pumps in the pumping station according wiring diagram
in operating instructions PT 0030 BN of the Backing Pump Relay Boxes:
Fig. 5: Connection with relay box (PM 041 937 GT) to TC 600
Switch position: "115" "230"
Voltage ranges: 100 ... 120 V, 50/60 Hz 200 ... 240 V, 50/60 Hz
11 5
230
11 5
230
1
FV Pump
MVP-Reihe
MVP series
TC 600
L
N
PE
PE
N
L´
2
3
4

13
Installation
5.5 Retrofitting the gas ballast valve
As an option, the MVP 055-3 can be retrofitted with a gas ballast valve.
Installation
The gas ballast valve may only be installed on membrane head 3.
ÎHollow screw 15 at the outlet (Ex) to membrane head 3 using a SW 17 open-end
wrench.
ÎRemove hollow screw 15 and assemble gas ballast valve, seals and spacer (SW
17).
Fig. 6: Fitting the gas ballast valve
B Membrane head 2
C Membrane head 3
D Membrane head 4
15 Hollow screw
40 Gas ballast valve
C
15
D
B
40

14
Operation
6 Operation
6.1 Before switching on the pump
ÎCompare the voltage information on the rating plate with the mains voltage.
ÎCheck that the exhaust connection allows free flow (max. permissible pressure
1.1 bar absolute).
– Activate the shut-off valves in such a way that they open before or at the same
time as the pump is started.
ÎProtect the pump sufficiently from taking in contaminants by means of suitable
precautions (e.g. dust filters).
6.2 Switching on the pump
The pump can be switched on in any pressure range.
No special precautions are necessary when pumping dry gases. In order to attain
the lowest possible final pressures, the gas ballast valve should be closed.
The pump attains the stated values for throughput rates and final pressure levels
only once the operating temperature is reached (after approximately 15 minutes).
ÎSwitch on the pump with the vacuum flange closed and allow to warm up for 15
minutes.
6.3 Pumping condensable vapors
Should the process gases contain condensable gases present at high percentages,
the vacuum pump must be operated with a gas ballast (i.e. with an open gas ballast
valve).
CAUTION
Dangerous overpressure overload!
Mixing up the connections leads to a dangerous overpressure overload in the pump,
and the motor could be damaged.
ÎBefore commissioning, it is imperative that you ensure that the pressure does rise
above the maximum permissible pressure on the pressure side.
ÎStart pumps at a maximum pressure differential of 1 bar between inlet and outlet.
CAUTION
Hot surface!
Danger of burns if hot parts are touched. Depending on the operating and ambient
conditions, the surface temperature of the pump may rise above 70°C.
ÎIn this case, use suitable finger guards.

15
Operation
Gas ballast valve Letting in gas ballast improves the discharge of condensate, and the pump
achieves the specified final vacuum more quickly. The gas ballast valve can be re-
placed with a flushing gas connection if necessary.
The gas ballast valve is closed when turning to the right to position 0 and open
when turning to the left to position 1. Intermediate settings are not possible.
Fig. 7: Operation with gas ballast valve
ÎOpen gas ballast valve; to do so, turn cap 43 on the gas ballast valve 40 so that
the two holes line up.
WARNING
Reactive, explosive or otherwise dangerous mixtures!
Uncontrolled gas inlet at the gas ballast valve can result in dangerous mixtures.
ÎBy implementing the required safety measures, the user must prevent potentially ex-
plosive mixtures from occurring in the inside of the pump and from being ignited in
the event of a diaphragm crack by mechanically produced sparks, hot surfaces or
static electricity.
ÎIf necessary, use inert gas for ventilation and gas ballast supply.
NOTE
Bad final vacuum and damage to the pump!
Danger of condensation and a reduced final vacuum during operation without a gas
ballast or in case of insufficient supply of flushing gas.
ÎOnly pump vapors when the pump is warm and the gas ballast valve is open.
ÎWhen the process has been completed, allow the pump to continue running for
about 30 minutes at atmospheric pressure with the gas ballast open.
40 Gas ballast valve
43 Cap
43
40
☞
NOTE
The pump achieves the specified values for throughput and final pressure after
the operating temperature has been achieved and with the gas ballast valve
closed.

16
Operation
Installing the flushing
gas connection
The MVP 055-3C can be equipped with a flushing gas connection as an option.
Assembly
ÎDisconnect connection line from gas ballast valve.
ÎDismantle gas ballast valve and replace with flushing gas connection piece.
ÎRestore connection line and connect inert gas line.
– As a rule, let in dry air or pure nitrogen.
6.4 Switching off the pump
The pump can be switched off in any pressure range.
NOTE
Do not exceed maximum inlet pressure of 1.1 bar (absolute) at the flushing gas
connection!
This can result in damage to the diaphragms.
ÎProvide a pressure reducer.

17
Maintenance
7 Maintenance
7. 1 P r e c a u t i o n s
The valves and the diaphragms are wear parts. If the rated ultimate vacuum is no
longer achieved, the pump interior, the diaphragms and the valves must be
cleaned and the diaphragms and valves must be checked for cracks or other dam-
age.
Depending on individual cases it may be efficient to check and clean the pump
heads on a regular basis. In case of normal wear the lifetime of the diaphragms and
valves is > 10000 operating hours.
ÎAllow the pump to cool to a safe temperature.
ÎOnly dismantle the pump as far as necessary in order to repair defects.
ÎUse only alcohol or similar agents for cleaning pump parts.
ÎRestore the original hose connections between the individual pumping stages.
– The intake connections of the pumps are marked "IN" and the outlets "Ex" at
the diaphragm heads.
WARNING
Danger of injury from moving parts!
After power failure or motor shutdown due to overheating, the motor may restart auto-
matically.
ÎSecure the motor so that it cannot be switched on while any work is being performed
on the pump.
ÎIf necessary, dismantle the pump from the installation for inspection.
WARNING
Pump parts may be contaminated from pumped media!
Danger of poisoning due to contact with harmful substances.
ÎDecontaminate the pump before carrying out any maintenance work.
ÎIn the event of contamination, take suitable safety precautions to prevent your health
from being harmed by any dangerous substances.
NOTE
Service work should only be carried out by qualified personal!
Pfeiffer Vacuum is not liable for any damage to the pump resulting from work carried
out improperly.
ÎTake advantage of our service training programs from technical training; additional
information at www.pfeiffer-vacuum.net.
ÎPlease state all the information on the pump rating plate when ordering spare parts.

18
Maintenance
Check list for inspections and maintenance
Certain repair and overhaul work should only be performed by Pfeiffer Vacuum
Service (PV). Pfeiffer Vacuum will be released from all warranty and liability claims
if the required intervals for inspection, maintenance, or overhaul are exceeded or
inspection, maintenance, repair or overhaul procedures are not performed proper-
ly. This also applies if replacement parts other than Pfeiffer Vacuum OEM replace-
ment parts are used.
Depending on the process, the required intervals for inspection and maintenance can exceed the
typical values specified in the table. Please consult Pfeiffer Vacuum if necessary.
7.2 Cleaning and replacing diaphragm and valves at MVP 035-2
Cleaning and repla-
cing the valves
ÎAllow the pump to cool down before beginning dismantling.
ÎDetach the pump from the mains and the pumping system and ensure the motor
cannot get switched on.
ÎUnscrew the hose connection between the pump stages by loosening the hol-
low screw with a wrench (size 17).
ÎRemove the cheesehead screws 26 (four per membrane head).
ÎRemove housing cover G1 with head cover K1 taking care to prevent head cover
falling out of housing cover.
ÎCheck diaphragm pair 10 for damage and replace if necessary.
ÎRemove head cover K1 from housing cover G1 to check valve seals 11.
ÎTaking care with the position of valve seals 11, remove and check for damage,
and replacing if necessary.
Activity daily as required; at least once every six months as required; at least annually as required; at least every 2 years
Check silencer for contamination X
Clean, change valves and diaphragms X
Change silencer X
NOTE
Damage to the pump
The two membrane heads have differing head covers K1/K2 and housing covers G1/
G2. Head cover K1 has, on the intake side, and the housing cover G2 has, on the outlet
side, an additional groove in the valve seating.
ÎWhen serviceing take care not to interchange these two parts.

19
Maintenance
Fig. 8: Position of valve seals in the head cover
ÎClean all parts.
ÎRe-assemble pump in reverse order.
ÎCheck the other membrane head in the same way.
Fig. 9: MVP 035-2
Changing the Diaphragm
ÎDismantle membrane heads as described before.
☞
NOTE
Damage to the valve seals
Valve seals can be destroyed by gluing to after wrong installation.
ÎPay attention to the fitting position of the inlet and outlet valve seals. The valve flap
of the valves may not cover the groove in the head and housing cover K/G.
Nut/
groove/
rainure
11
G1 17 6 4 D 9 10 3 16 K2 G2 26
40 A1
2.3 K1
2.1
2.3
11
A1 Vacuum inlet with hose
connection
D Tolerance ring
G1 Housing cover inlet side
G2 Housing cover outlet side
K1 Head cover inlet side
K2 Head cover outlet side
2.1 Silencer
2.3 Sealing ring
3 Diaphragm spring washer
4Con-rod
6 Housing panel
9 Diaphragm support washer
10 Diaphragm pair
11 Inlet and outlet valve
seal
16 Countersunk screw
17 Countersunk screw
26 Cheesehead screw
40 Gas ballast valve

20
Maintenance
ÎUnscrew housing panel 6.
ÎRemove screw 16; this screw has been stuck to make secure against loosening.
ÎDismantle diaphragm spring washer 3, diaphragm pair 10 and diaphragm sup-
port washer 9.
– If it is difficult to separate the old diaphragm from support washer 9, apply e.g.
alcohol or petroleum ether.
Assembling ÎWhen existing, re-fit spacers D under the diaphragm support washer 9. Fix in
place with a little grease to prevent them falling down.
ÎPut two single diaphragms with their rough side together so that the labelled
side of the two diaphragms are readable.
ÎArrange diaphragm support washer 9, diaphragm pair 10 and diaphragm spring
washer 3 onto screw 16.
ÎPlace some threadlocker (low strength) under the head of screw 16 and screw in
con-rod 4.
ÎRefit head cover, valve seals and housing cover in reverse order, taking care with
the position of valve seals 11.
7.3 Cleaning and replacing diaphragm and valves at MVP 055-3
Cleaning and repla-
cing the valves
ÎAllow the pump to cool down before beginning dismantling.
ÎDetach the pump from the mains and the pumping system and ensure the motor
cannot get switched on.
ÎUnscrew the hose connection between the pump stages by loosening the hol-
low screw with a wrench (size 17).
ÎRemove the cheesehead screws 26 (four per membrane head).
ÎRemove housing cover G1 ... G4 with head cover K1 ... K4 taking care to prevent
head cover falling out of housing cover.
ÎCheck diaphragm pair 10 for damage and replace if necessary.
ÎRemove head cover K from housing cover G to check valve seals 11.
ÎTaking care with the position of valve seals 11, remove and check for damage,
and replacing if necessary.
NOTE
Damage to the pump and reduced final vacuum!
A changed dead centre (TDC) leads in the most unfavorable case to a bearing damage.
ÎCheck for washers D under diaphragm support washer.
ÎMake sure that the original number is reassembled at the individual membrane head.
☞
NOTE
Damage to the valve seals!
Valve seals can be destroyed by gluing to after wrong installation. The inlet valve seal
(11a) of membrane head 4 and the outlet valve seal (11b) of membrane head 3 differ
from all other valve seals.
ÎDo not exchange when assembling the membrane heads.