BOC Edwards EO2K User manual

B304–09–880 Issue G Original
Instruction Manual
EO2K, EO4K and EO6K Diffusion Pumps

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EO2K, EO4K and EO6K Diffusion Pumps
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CONTENTS
Section Page
1INTRODUCTION 1
1.1 Scope and definitions 1
1.2 Description 2
1.3 Principle of operation 2
1.4 Performance 2
1.5 Operation with high ambient humidity 3
1.6 Accessories 3
1.7 Applications 3
2TECHNICALDATA 9
2.1 Operating and storage conditions 9
2.2 Performance 9
2.3 Mechanical data 12
2.4 Pump fluid data 12
2.5 Cooling-water data (water-cooled pumps only) 12
2.6 Cooling-air data (air-cooled EO2K only) 15
2.7 Electrical data 15
2.8 Materials of construction 15
2.9 Item Numbers 15
3 INSTALLATION 17
3.1 Safety 17
3.2 Unpack and inspect 17
3.3 Locate the pump 19
3.3.1 General requirements 19
3.3.2 Installation on a vacuum system 19
3.3.3 Free-standing installation 20
3.4 Vacuum connections 20
3.4.1 System design 20
3.4.2 Connect the pump inlet and outlet 21
3.5 Make the electrical connections 23
3.5.1 Introduction 23
3.5.2 Connect the heater electrical supply 24
3.5.3 Connect the fan electrical supply (EO2K air-cooled pump only) 24
3.6 Fit optional thermal snap-switches 24
3.7 Connect the cooling-water pipelines (water-cooled pumps only) 26
3.8 Leak-test the system 27
3.9 Fill the pump with fluid 28
3.9.1 Safety of vapour pump fluids 28
3.9.2 Recommended pump fluids 28
3.9.3 Filling procedure 29
Ipsitech 8178–06

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Section Page
4OPERATION 31
4.1 General safety 31
4.2 Check the electrical safety of the pump 32
4.2.1 Check the earth (ground) continuity 32
4.2.2 Check the insulation resistance of the heaters 32
4.3 Start-up 33
4.4 Readmission of air to your vacuum system 33
4.5 Re-evacuation of your vacuum system 34
4.6 Shut-down 34
4.6.1 Introduction 34
4.6.2 Shut down the EO pump 36
5 MAINTENANCE 37
5.1 Safety 37
5.2 Tools and equipment required 38
5.3 Maintenance plan 38
5.4 Check the pump fluid-level 39
5.5 Inspect the pump fluid condition 40
5.6 Clean the pump 40
5.6.1 Introduction 40
5.6.2 Dismantle the pump 40
5.6.3 Clean the pump components 41
5.6.4 Reassemble the pump 41
5.7 Clean the radiation shield 42
5.8 Replace the pump heater 42
5.8.1 Remove the old heater 42
5.8.2 Fit the new heater 43
5.9 Check the heater securing nut 43
5.10 Clean the cooling-coil 43
5.11 Fault finding 43
6 STORAGE AND DISPOSAL 47
6.1 Storage 47
6.2 Disposal 47
7 SERVICE, SPARES AND ACCESSORIES 49
7.1 Introduction 49
7.2 Service 49
7.3 Spares 49
7.4 Accessories 49
RETURN OF BOC EDWARDS EQUIPMENT

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ILLUSTRATIONS
Figure Page
1 Sectional view of the EO2K pump (water-cooled version) 4
2 Sectional view of the EO2K pump (air-cooled version) 5
3 Sectional view of the EO4K pump 6
4 Sectional view of the EO6K pump 7
5 EO2K pumping speed (l s-1) against pressure (mbar/Pa) 10
6 EO4K pumping speed (l s-1) against pressure (mbar/Pa) 10
7 EO6K pumping speed (l s-1) and throughput (mbar l s-1) against pressure (mbar/Pa) 11
8 EO2K dimensions (mm) 13
9 EO4K dimensions (mm) 13
10 EO6K dimensions (mm) 14
11 EO4K inlet connection options 22
12 Recommended electrical supply and control circuit 25
13 Heater electrical supply connections 25
14 Cooling-water connections 27
15 Typical pumping system configuration 35
16 Fluid drain plugs 39
TABLES
Table Page
1 Operating and storage conditions 9
2Performancedata 9
3 Mechanical data 12
4 Pump fluid data 12
5 Cooling-water data 12
6 Cooling-air data (air-cooled EO2K only) 15
7 Electrical data 15
8 Materials of construction 15
9ItemNumbers 15
10 Checklist of items: EO2K fitting-pack 18
11 Checklist of items: EO4K fitting-pack 18
12 Checklist of items: EO6K fitting-pack 18
13 Vapour pump fluid thermal breakdown 29
14 Maintenance plan 38
15 Fault finding 44
16 Spare pump fluids and anti-seize compound 49
17 EO2K pump spares 50
18 EO4K pump spares 50
19 EO6K pump spares 50
20 EO2K pump accessories 51
21 EO4K pump accessories 51
22 EO6K pump accessories 51

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EO2K, EO4K and EO6K Diffusion Pumps
INTRODUCTION
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1INTRODUCTION
1.1 Scope and definitions
This manual provides installation, operation and maintenance instructions for the BOC Edwards EO2K,
EO4K and EO6K Diffusion Pumps, abbreviated to “EO pump” or “pump” in the remainder of this manual.
You must use the pumps as specified in this manual. Read this manual before you install and operate the
pump.
Important safety information is highlighted as WARNING and CAUTION instructions; you must obey
these instructions. The use of WARNINGS and CAUTIONS is defined below.
The units used throughout this manual conform to the SI international system of units of measurement.
The following warning symbols are on the pump:
Warning – refer to accompanying documentation.
Warning – risk of electric shock.
Warning – hot surfaces.
WARNING
Warnings are given where failure to observe the instruction could result in injury or death
to people.
CAUTION
Cautions are given where failure to observe the instruction could result in damage to the equipment,
associated equipment and process.

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1.2 Description
The EO series of pumps are compact, high-performance diffusion pumps. The pumps provide clean
pumping and minimum pump-down times, even when high-vapour loads are pumped. Three models of
pumps are available.
The EO2K, EO4K and EO6K pumps have a vacuum-brazed stainless steel body and a precision machined
aluminium interior. The component parts of these pumps are shown in Figures 1 to 4.
The body of the EO pump has a top-flange, a main body tube and a condenser assembly. All EO pumps
are available as water-cooled pumps. These pumps are cooled by water which flows through a stainless
steel cooling-coil wound around the main body and vacuum brazed to provide maximum cooling
efficiency. The condenser has a pre-formed stainless steel cooling-coil wound around it for optimum
cooling.
The EO2K pump is also available as an air-cooled pump. Refer to Figure 2. On the air-cooled EO2K
pump, the backing condenser has cooling-fins (2) and a cooling-jacket (1) is attached to the pump-body’
air is blown over the fins of the cooling-jacket by an integral electric cooling-fan (6).
The interior assembly has three fully-fractionating jet-stages and an ejector-stage. Above the top jet-stage
is a detachable jet-cap with a guard-ring. A plate heater inside the base of the pump heats the pump fluid
to generate the required vapour. A radiation shield is attached to the underside of the heater.
The electrical supply cables from the heater are brought out to a terminal-box at the bottom of the pump
for ease of connection to your electrical supply.
1.3 Principle of operation
The arrows in Figures 1 to 4 show the flow of vapour through the pumps. Pump fluid is heated in the
boiler to produce a vapour which passes up through the interior of the jet assembly and emerges from
the jets as high-velocity vapour streams. The vapour streams condense on the cooled pump-body wall
and drain into the boiler at the bottom of the pump for recirculation.
A portion of system gas which arrives at the pump-inlet is trapped in the vapour stream from the first-
stage jet. The gases are compressed and transferred to the next stage. This process is repeated through
the pump jet-stages until the gases are removed by the backing-pump through the cooled backing-
condenser.
The guard-ring above the top-jet is designed to minimise any back-streaming of pump fluid vapour by
trapping and condensing it on the cooled surface of the guard-ring.
The fractionating feature of the EO pump design provides a means of purging the fluid charge of
undesirable light fractions and foreign matter and the process helps significantly towards the attainment
of a low ultimate vacuum. The ejector-jet also purges the fluid of any contaminants as it returns to the
boiler and at the same time ensures a high critical backing pressure, even when you use low vapour
pressure fluids.
1.4 Performance
The ultimate vacuum depends on the fluid used in the pump, the leak tightness of the system, outgassing
from surfaces and the use of cold traps.
The performance values given in Section 2.2 are likely values which can be achieved with a clean system.

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1.5 Operation with high ambient humidity
When the EO pump is switched off, the heater in the pump will absorb moisture: this will cause a
decrease in the insulation resistance of the heater. If you operate the pump in an environment with high
ambient humidity, this may cause the heater to fail. The rate of moisture absorption (and therefore the
time taken for the insulation resistance of the heater to fall below the recommended value) depends on
the ambient humidity and temperature and the length of time that the pump is switched off.
In addition to the recommendations made in later sections of this manual, you can overcome the effect
of high ambient humidity if you:
• Configure the electrical installation of the pump for ‘soft-start’ operation, when the pump is
operated with typically 20 to 25% of the nominal supply voltage.
• Install an anti-moisture heater under the base of the pump. Switch on this heater when you switch
off the pump.
Detailed information about these recommendations is outside the scope of this manual. If you need more
information about the operation of the pump with high ambient humidity, request a copy of our
Application Note P400-50-000 from your supplier or BOC Edwards.
1.6 Accessories
A wide range of accessories is available for the EO pumps. This range includes vacuum fittings, valves, and
the following thermal snap-switches:
•Cooling-fail thermal snap-switch - This accessory can be fitted to all of the water-cooled EO
pumps, to protect the pump against damage due to failure of the cooling-water supply. If the
temperature of the pump increases above the normal operating temperature, the snap-switch will
operate to disconnect the heater from the electrical supply. The snap-switch automatically resets
when the temperature of the pump returns to normal.
•Pump-ready thermal snap-switch - This snap-switch can be fitted to EO4K pumps. The snap-
switch will open to indicate that the pump has reached operating temperature. This snap-switch
can be used to control the operation of your vacuum system isolation-valve.
Refer to Section 7.4 for a full list of accessories available for the EO pumps.
1.7 Applications
The EO pumps are suitable for a wide range of applications, including scientific and research and
development pumping applications.
If you are unsure about the use of the EO pump on your application, please contact your supplier or BOC
Edwards for advice.

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Figure 1 – Sectional view of the EO2K pump (water-cooled version)
1. Top-jet pin
2. Guard-ring assembly
3. NW10 elbow
4. NW10 centring-ring
5. NW10 clamping-ring
6. Backing connection
7. Condenser baffles
8. Backing-spout
9. Ejector-jet
10. Heater terminal block
11. Terminal-box
12. Heater electrical lead
13. Heater assembly securing nut
14. Heater
15. Radiation shield
16. Pump-body
17. Cooling-coil
18. Third-stage jet
19. Interior jet assembly
20. Cooling-fail thermal snap-
switch mounting plate
21. Second-stage jet
22. First-stage jet
23. Pump inlet-flange
24. Co-Seal
Process gases
Pump fluid vapour