GA01300_0902 - 04/2006 - © by Leybold Vacuum
30
Maintenance
5.4
Oil Change
Before pumping oxygen (or other highly reactive gases) at con-
centrations exceeding the concentration in the atmosphere
(> 21 % for oxygen) it will be necessary to use a special pump.
Such a pump will have to be modified and de-greased, and an
inert special lubricant (like PFPE) must be used.
Hazardous substances may escape from the pump and the oil.
Take adequate safety precautions. For example wear gloves, face
protection or breathing protection.
Observe all safety regulations.
Mineral oil (N 62 or HE 200)
For proper operation of the pump, it is essential that the pump has an ade-
quate supply of the correct and clean oil at all times.
The oil must be changed when it looks dirty or if it appears chemically or
mechanically worn out.
The oil should be changed after the first 100 operating hours and then at
least every 2,000 to 3,000 operating hours or after one year. At high intake
pressures and intake temperatures and/or when pumping contaminated
gases, the oil will have to be changed more frequently.
Further oil changes should be made before and after long-term storage of
the pump.
If the oil becomes contaminated too quickly, install a dust filter and/or oil fil-
ter. Contact us for more information in this matter.
PFPE
PFPE lubricants are chemically almost inert. Thus they do not suffer ageing
like mineral oils, for example.
However, PFPE lubricants offer a reduced dispersing behaviour compared
to that of mineral oils. For this reason, any contaminant particles entering
into the pump may deposit themselves within the pump and cause dama-
ge. The ingress of process media can also cause impairments within the
pump, for example through condensation and a reduction in the attainable
ultimate pressure or by attacking components through aggressive media.
In this case pumps with a filling of PFPE must always be operated in
connection with a suitable oil filter facility.
When the oil filter facilities are changed early enough, it will only be requi-
red to exchange the PFPE rarely. In such cases we recommend to exchan-
ge the PFPE once a year to be on the safe side.
Shorter oil change intervals will be necessary in the case of
■
inadequate oil filter facilities
■
oil filter changes which are done too late
■
when pumping contaminated gases
■
when pumping extremely reactive substances.
How often a PFPE exchange will be necessary can only be decided on a
case-by-case basis depending on the level and type of contamination.
Warning
