Installation and connection
20901552_EN-US_PC301x NT V.sel (Ser.Atb_Ha)_V1.1_160822
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4.4.5 Gas ballast (GB)
Use ambient air as gas ballast
DANGER
Explosion risk due to air as gas ballast.
By using air as a gas ballast, a small amount of oxygen en-
ters the inside of the vacuum pump. Depending on the
process, a potentially explosive mixture can form due to
oxygen in the air, or other dangerous situations can occur.
Ø
In the presence of flammable substances and for pro-
cesses in which a potentially explosive mixture can oc-
cur, use only inert gas as a gas ballast, e.g. nitrogen (max.
1.2 bar/900 Torr abs.).
Gas ballast valve po-
sition
If ambient air is to be used as gas ballast, nothing needs to be con-
nected at the pumping unit; gas ballast valve
(a)
; see also chapter:
