SK00-4802-DI-002-04
No.16.10.20
6
2. Overview
2.1 About oil diffusion pump
The principle of an oil diffusion pump is that gas molecules coming into the pump inlet are captured
by injected stream and flow downstream with the injected stream. The gas molecules flowing
downstream by the injected stream cannot pass through the thick upstream layer of injected stream
and further flow downstream. The injected stream then comes into collision with the water-cooled
pump case surface, condenses there, discharges thermal energy, turns into liquid again.
The oil diffusion pumps under the ULK series are each largely classified into the following four
parts:
1) Four-stage injection nozzle (Aluminum)
2) Pump case with cooling water pipe (Stainless)
3) Boiler to heat oil up
4) Air outlet baffle nozzle to prevent oil consumption
Figure 1: Part name of ULK type oil diffusion pump
Nozzle
Cooling water inlet
Pump case
Boiler (Cover)
Terminal box
Air inlet
(Loose type flange)
Air outlet baffle
Cooling water outlet
Air outlet
(Loose type flange)
Oil filler port
Oil drain port
