YK08-0028-DI-002-08
30
6.2.1 Pump Oil Level Check
The pump oil level should be between the two level lines (MAX and MIN) on the oil level gauge.
(Refer to the ” Fig. 3 Lubrication and oil level indication”.)
6.2.2 Vacuum Pump Oil Check
The vacuum pump oil will be gradually deteriorated not only by contamination with sucked gas,
but also by temperature rise during pump operation. Check the oil for contamination and
viscosity and discoloring periodically.
If substances of low boiling point (water, organic solvent, etc.) are mixed with pump oil or
sludge collects on the bottom of the pump case, the ultimate pressure cannot be recovered by
one oil change, but the oil must be changed several times.
If the pump is operated using pump oil containing much moisture content, the ultimate pressure
will rise, leading to poor functioning of the mechanical friction parts of the pump. In the worst
case, the pump will seize up and cannot be rotated.
Table. 4 gives a guide for pump oil change frequency.
CAUTION
“VD201”
The oil level gauge is for checking the pump oil level. Since the oil is
not circulating between the pump case and the oil level gauge,
contamination or discoloring of the oil may not be observed on the
oil level gauge. Periodical ly drain approx. 50 mi, of oil through the
drain valve and check the oil for contamination and discoloring.
Table. 4 Recommended replacement cycle of the vacuum pump oil
Purpose
Replacement timing
Vacuum system for study / laboratory, small
vacuum system
Within 6 month ~ 1 year
Vacuum system for production, vacuum evaporation Within 3 ~ 6 month
Vacuum valve exhaust system, large vacuum
evaporation system
Within 3 month
Metallurgy vacuum system such as thermal
treatment, melting and the like
Within 1 month
High vacuum dry, vacuum impregnation, vacuum
formation and vacuum packing system
Within 1 month
Low vacuum dry, pug mill and food packing system Within 1 week
