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Page 15
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MAINTENANCE
B756-50-880 Issue C
5
MAINTENANCE
5.1
Introduction
The maintenance operations for the EXT70/70/200H Split Flow pump are described in the following sections. The
procedure for extraction and fitting of the cartridge pump from the system chamber is also covered below. This
procedure should be followed at all times when removing and refitting the EXT70/70/200H Split Flow pump.
5.2
Removing the cartridge pump from the system
1. Shut down the system in accordance with operating instructions and raise it to atmospheric pressure.
2. Remove the electrical and vacuum fittings from the rear of the cartridge pump.
3. Remove the four M6 x 30 cap head bolts from around the flange of the cartridge pump (see
). A black
plastic plug screwed into the side of the body may obscure one of the M6 bolts. In this case, remove the plug
from the body to allow removal of the bolt and replace it when the bolt has been removed.
4. The cartridge pump is removed from the chamber by tightening of the two nylon jacking screws fitted to the
flange of the cartridge pump (see
). The screws should be finger tightened until they both rest firmly
against the body of the pump. They should then be tightened in sequence, half a turn at a time, until the pump
is backed out of the chamber. The cartridge pump will need to be backed off using the nylon screws by
approximately 5mm before the three piston seals come free of their normal seating areas and the pump is able
to be pulled free of the chamber. Great care must be taken when withdrawing the cartridge pump from the
envelope to avoid scratches and other damage to the internal bore of the chamber and the O-ring lands of the
cartridge pump.
5. Store the cartridge pump in an upright position on the four rubber feet at the base of the pump.
WARNING
Allow the pump rotor to stop, then disconnect the controller before removing the pump from the
vacuum system for maintenance or fault finding purposes.
WARNING
Ensure that the rotor has come to a complete standstill and that the cartridge pump is electrically
isolated before proceeding with its removal.
