6.3 Switching on vacuum pump
WARNING
Danger of poisoning due to toxic process media escaping from the exhaust pipe
During operation with no exhaust line, the vacuum pump allows exhaust gases and vapors to escape
freely into the air. There is a risk of injury and fatality due to poisoning in processes with toxic process
media.
► Observe the pertinent regulations for handling toxic process media.
► Safely purge toxic process media via an exhaust line.
► Use appropriate filter equipment to separate toxic process media.
CAUTION
Danger of burns on hot surfaces
Depending on the operating and ambient conditions, the surface temperature of the vacuum pump
can increase to above 70 °C.
► Provide suitable touch protection.
Procedure for roots pumps with an overflow valve
► Switch on the roots pump at the same time as the backing pump.
– The overflow valve is open at the beginning of evacuation in high pressures ranges. This pro-
tects the Roots pump from overload.
– The overflow valve closes as soon as the differential pressure between the suction side and
pressure side falls below 20 hPa.
Procedure for roots pumps with blocked overflow valve
► Do not switch on the roots pump with blocked overflow valve until a fore-vacuum pressure has
been reached at which the backing pump can handle the conveyed volume of gas.
– Depending on the pumping speed of the backing pump (S
V
), the fore-vacuum pressure for
the roots pump is calculated as (p
V
) = 70 hPa/(1 – S
V
/S
th
).
Example:
● Okta ATEX with nominal pumping speed S
th
= 2155 m
3
/h at 50 Hz
● Backing pump with pumping speed S
V
= 250 m
3
/h at 50 Hz
● Cut-in pressure p
V
= 70 hPa/(1 – 250 [m
3
/h]/2155 [m
3
/h]) =
79.2 hPa
Impermissible continuous operation
Continuous operation of the roots pump with this pressure differential is not permissible as
the maximum gas temperature will be exceeded in the exhaust channel.
Switching on
1. Switch the vacuum pump on.
2. Allow the vacuum pump to warm up for approx. 30 minutes prior to process start with the vacuum
flange closed.
3. Check the lubricant level with the vacuum pump running and at operating temperature.
– The fill level must be within the marks on the sight glass during operation.
4. Check the fill level daily during continuous operation, and every time the vacuum pump is switch-
ed on.
6.4 Adjusting the sealing gas amount
WARNING
Risk of injury from reactive, potentially explosive or other hazardous gas/air mixtures
Uncontrolled gas inlet of air or gases containing oxygen provides ideal conditions for the formation of
unexpected explosive gas/air mixtures in the vacuum system. This results in severe injuries.
► Use only inert gases for supplying the sealing gas supply in order to avoid a potential ignition.
Operation
36/62
Summary of Contents for OKTA 2000 ATEX
Page 1: ...OPERATING INSTRUCTIONS EN Translation of the Original OKTA 2000 ATEX Roots pump ...
Page 62: ...Notizen Notes ...
Page 63: ......