Edwards nEXT 55, Instruction Manual

Page: 22 / 116

3.3 Vent gas specification and vent control data
The pump can be vented to atmosphere, but the high relative humidity of the air can
increase the subsequent pump
‑
down time. To decrease the pump
‑
down times, vent
with dry and clean gases. Refer to Vent options, vent valve connection and control on
page 72 for the vent options and the vent valve connection. Refer to Controlled venting
options on page 64 for configuring the venting options.
Table 3
Vent gas specification and vent control
Vent gas specification and control Reference data
Vent gas Dry air, nitrogen, argon or other inert
gases
Maximum dew point at an atmospheric
pressure
-22 °C
Maximum size of particulates 1 µm
Maximum concentration of oil 0.1 parts per million
Recommended time for the rotational speed
to reach 50%
> 15 seconds
Maximum permitted rate of increase of
pressure
Refer to Figure: Maximum allowed rate
of increase in pressure during venting:
pressure against time (pump initially at
full speed) .
Maximum permitted vent gas supply pres-
sure
1 bar (gauge), 14.5 psig, 2 x 10
5
Pa
Figure 10 Maximum allowed rate of pressure rise during venting: pressure against time (with
pump initially at full rotational speed)
3.4 Purge gas specification
07/2021 - ©Edwards Limited Page 22 B8G000880_E
B8G000880_E - Technical data