EXT556H turbo pump user manual

EXT556H
2.2.1 Pumps without gas purge
PAGE
4
TECHNICAL DATA
The pumps are designed to pump the following residual gases normally used in high vacuum systems:
• Air
• Nitrogen
• Krypton
•Neon
• Hydrogen
• Propane
•Methane
You can use the pumps to pump oxygen and water vapour subject to the following conditions:
•Oxygen
• Carbon dioxide
• Carbon monoxide
• Helium
•Argon
• Ethane
• Butane
The oxygen concentration must be less than 20% by volume unless a bearing purge is applied as detailed
in Section 2.2.2.
• Water vapour
You must ensure that vapour does not condense inside the pump - refer to Section 3.7.3.
If you wish to pump a gas not previously listed, contact your supplier for advice. If you do not contact your
supplier you may invalidate the warranty on the pump.
The pumps are not suitable for pumping aggressive or corrosive gases.
2.2.2 Pumps with gas purge
When purged with an inert gas the pumps can be used to pump oxygen in concentrations above 20% by volume.
2.3 Vent gas specification and vent control data
Although the pump may be vented to atmosphere, relatively high air humidity may greatly increase the
subsequent pump-down time. To reduce pump-down times you should vent the pump with dry, clean gases.
Vent gas system items
Reference data
Vent gas
Dry air, nitrogen, argon or other inert gases
Maximum dew point at atmospheric pressure -22 °C
Maximum size of particulate
Maximum concentration of oil
Time for rotational speed to reach 50%
1 micron
0.1 parts per million
>15 seconds
Maximum allowed rate of pressure rise see Figure 4
Table 2 - Vent gas and vent control data
Issue A 4
Aug 05