30
6
MAINTENANCE AND SERVICING
6.3 Oil Change
6.4 Shaft Seal Replacement
6.5 Major Factory Repair
6.3.3 Flushing
If the oil is heavily contaminated, the vacuum pump must be flushed, e.g.:
•
Heavy clouding by condensates
•
Suspended particles such as dust, fibres, abraded particles
•
Dark coloration of the oil
The flushing liquid should be the type of oil which is currently being used.
1. After the vacuum pump has been filled with fresh oil, allow it to warm up by running it with the suction
port closed. If you have established that the old oil, which you have previously drained, was contaminated
by condensate (e.g. water) then the gas ballast valve must be open.
2. Drain the flushing oil. If the oil still appears heavily contaminated, the flushing procedure must be repeated.
6.3.4 Frequency of Oil Changes
The oil change interval is completely dependent upon the running conditions of temperature, operating pressure,
hours of daily operation, and upon the materials pumped. Clean, dry air at pressures below 0.7 mbar (50 mtorr)
are the most forgiving conditions. To determine your own oil change interval, visually monitor the pump oil
conditions at regular intervals. If you suspect harsh operating conditions, daily visual checks are recommended.
When the oil becomes cloudy, dark or includes particles of solids, it is time to change the oil. Be sure to use
only Directorr™ Premium vacuum oil. The ultimate pressure guarantee applies only if this oil is used!
When the shaft seal in the mounting plate shows signs of excessive oil leakage, it should be replaced.
Before attempting replacement of the seal, the pump must be disconnected from the vacuum system
and from the power outlet. A seal replacement kit is available. This kit contains the outer lip seal assembly
and gasket, which can be replaced in the field. See chapter 9 “Overview of Spare Parts”.
Repairs and maintenance going beyond the extent of the work described in the previous chapters or
reconditioning or modification may only be performed by the manufacturer or authorized workshops.
Drain the oil before dispatching the pump and dispose of the oil according to the regulations.
The prerequisites for a handover are a complete and factually correct damage report, and a clean pump.
Clean the pump aggregate and the pump casing after pumping media which are harmful to health and
the environment. Fill up with sufficient oil to protect against corrosion during transport!
WARNING !
Incomplete or incorrectly completed damage reports may endanger the service personnel!
Provide full information about contamination, and clean the pump thoroughly before handing
it over to third parties. The user shall be liable for the consequences of an incorrect damage
report or a contaminated pump. The statements in the damage report are legally binding.
