Instruction manual
EXT Split Flow Compound Turbomolecular Pumps
MAINTENANCE
PAGE
21
Mar 07 21 Issue F
5MAINTENANCE
5.1 Introduction
The maintenance operations for the EXT Split Flow Pumps are described in the following sections. The
ISX Inlet-Screen, the WCX Water-Cooler, the inlet-strainer and inlet-flange seals are available as spares
(refer to Section 7). Fit the ISX Inlet-Screen as described in Section 3.3.2. Fit the WCX Water-Cooler
as described in Section 3.6.3.
5.2 Bearing maintenance
When supplied, the pump contains sufficient lubricant to supply the bearings for life. No routine
maintenance is therefore required between bearing replacements. The bearings are not user- serviceable.
The bearings will need to be replaced when they reach the end of their service life. This is typically more
than 20,000 hours, but may be less; this depends on the type of pumping duty on which the pump is used.
When the bearings need replacement, we recommend that you exchange your pump for a factory
reconditioned replacement. Alternatively, you can send your pump to a BOC Edwards Service Centre
to have the bearings replaced.
When you return EXT Split Flow Pumps to BOC Edwards Service Centres please use the procedure
included at the end of this manual. However, the instruction to drain all fluids does not apply to the
lubricant in the EXT Split Flow Pump oil-reservoirs.
5.3 Rotor life
The fatigue life of the EXT Split Flow Pump rotors is typically 40 000 to 50 000 cycles of acceleration
from rest to full speed and then back to rest. As a precautionary measure, BOC Edwards recommends
that pumps are returned for a major service (rotor replacement) after 20 000 cycles or ten years,
whichever occurs first.
WARNING
The EXT Split Flow Pumps are not to be serviced by the customer. Pumps requiring
servicing should be returned to BOC Edwards or serviced by a qualified BOC Edwards
engineer.
WARNING
Allow the pump-rotor to stop, then disconnect the controller before you remove the
pump from your vacuum system for maintenance or fault-finding procedures.
WARNING
Do not remove the EXDC Controller/EXC Controller cable from the pump until the
pump is completely at rest. To do so could expose personnel to hazardous voltage and
potentially damage the EXDC/EXC Controller.