BOC Edwards EO2K, Инструкция по эксплуатации

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EO2K, EO4K and EO6K Diffusion Pumps
OP
ERATION
PAGE
34
Issue G 34 Aug 06
4.5 Re-evacuation of your vacuum system
1. Refer to Figure 15. Close the vacuum system air-admittance valve (2) and any other openings to
atmospheric pressure.
2. Close the backing-valve (5).
3. Open the roughing-valve (4).
4. When the system pressure has fallen to 0.1 mbar (10 Pa) or below:
5. Close the roughing-valve (4).
6. Open the backing-valve (5).
7. Open the vacuum system isolation or baffle-valve (10) slowly; if you open the valve too quickly, you
can stall the EO pump.
4.6 Shut-down
4.6.1 Introduction
Use the procedure in Section 4.6.2 to shut down the pump.
As described in Section 1.5, 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.
To avoid the absorption of moisture when the pump is in an environment of high ambient humidity, we
recommend that you maintain the base flange temperature at a temperature between 20 and 30
o
C above
ambient temperature. Ensure that the base flange does not get too hot; if it does, the pump fluid may
vaporise and contaminate the vacuum system.
For more information about the operation of the pump in high ambient humidity, request a copy of our
Application Note P400-50-000 from your supplier or BOC Edwards.
If you have incorporated isolation valves in both the cooling-water supply and return pipelines:
• If you are going to shut down the pump in order to carry out maintenance, you must close both of
the water isolation valves.
• If you are not going to carry out maintenance, but are only going to shut down the pump in between
process pumping operations, we recommend that you only close one of the water isolation valves.
This will minimise the chance that the pump can subsequently be operated with both water isolation
valves closed: see the WARNING at the start of Section 4.3.