Design and Function
Vacuum Pump System SC 920G
16
Translation of original Operating Instructions, English, KNF 121308-121311 07/18
5.4. Pump
Design
1
Outlet valve
2
Inlet valve
3
Transfer chamber
4
Diaphragm
5
Eccentric
6
Connecting rod
7
Pump drive
Fig. 5: Pump design
Function Diaphragm pump
Diaphragm pumps transfer, compress (depending on pump
version) and evacuate gases and vapors.
The elastic diaphragm (
4
) is moved up and down by the eccentric
(
5
) and the connecting rod (
6
). In the downward stroke it aspirates
the gas to be transferred via the inlet valve (
2
). In the upward
stroke, the diaphragm presses the medium out of the pump head
via the outlet valve (
1
). The transfer chamber (
3
) is hermetically
separated from the pump drive (
7
) by the diaphragm.
5.5. Gas ballast
WARNING
Personal injury caused by poisoning or explosion
and damage to the pump
Make sure that no reactive or explosive mixtures
will be produced when the gas ballast valve is
open.
When transferring vaporous media, opening the gas ballast
valve can minimize the formation of condensation in the pump
heads.
Opening the gas ballast valve deteriorates ultimate vacuum
performance.
The gas ballast valve is opened and closed via the gas ballast
switch (see Fig. 6).
Please contact KNF Service if you require an inert connection for
the gas ballast.
Fig. 6: Gas ballast switch
