B753-03-880 Issue F
Page 8 © Edwards Limited 2008. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Technical data
You can use the pumps to pump oxygen and water vapour, subject to the following conditions:
If you wish to pump a gas not in the list above, 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 atmospheric air, high relative humidity of the air may greatly increase the
subsequent pump-down time. To reduce pump-down times you should vent the pump with dry, clean gases.
2.4 Purge gas specification
z Oxygen The oxygen concentration must be less than 20% by volume.
z Water vapour You must ensure that vapour does not condense inside the pump; refer to Section 3.7.3.
Vent gas Dry air, nitrogen, argon or other inert gases
Maximum dew point at atmospheric pressure - 22 °C
Maximum size of particulates 1
µm
Maximum concentration of oil 0.1 parts per million
Time for rotational speed to reach 50% >15 sec
Rate of pressure rise see Figure 3
Purge gas Dry nitrogen, argon or other inert gases
Maximum dew point at atmospheric pressure -22 °C
Maximum size of particulates 1
µm
Maximum concentration of oil 0.1 parts per million
Allowable purge gas flow (when required) 20 to 100 sccm (0.33 to 1.67 mbar l s
-1
, 33 to 167 Pa l s
-1
)
Recommended purge gas flow 25 sccm (0.42 mbar l s
-1
, 42 Pa l s
-1
)
Maximum allowable purge gas supply pressure 2 bar (gauge) ; 29 psig, 3 x 10
5
Pa
To Next Page
Loading...
