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Page 19
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Installation
B722-40-880 Issue H
3.3.1
Inlet screen (supplied fitted)
Remove the inlet screen only if there is no possibility that debris can fall into the pump. If the inlet screen is removed,
the pumping speed will increase by up to 10%. Since the inlet screen protects the pump from contamination, do not
remove the inlet screen until the pump is mounted on the system.
It is not possible to remove the inlet screen from a pump with an NW40 inlet flange (EXT75DX only).
To remove the inlet screen from a pump with an ISO or CF inlet flange, use a bent wire hook or small screwdriver to
carefully lever the inlet screen out from the inlet flange.
To replace an inlet screen, locate it as centrally as possible over the ISO or CF inlet flange and then, with fingers
applying equal pressure around the edge of the screen, push it firmly downwards. If they are not already in place,
the tangs must be snapped into the locating groove in the inlet flange using a suitable tool to press them into position.
Figure 5 - Correct installation of the inlet screen (EXT75DX)
3.3.2
Mechanical fixing
There are two ways in which the DX pumps can be securely fixed. The ideal fixing for a DX pump is via its inlet flange
to a rigid, firmly fixed vacuum system - refer to
. If this is not possible because of the nature of the
vacuum system, then the base of the pump must be fixed to a firm support. Refer to
for instructions
on base mounting the pump.
3.3.3
Inlet connection and orientation
The pump can be securely fixed to the vacuum system via the inlet flange. The pump can be mounted in any attitude
from the vertical and upright through to horizontal (
±
2°). If the pump is mounted horizontally, and a rotary vane
pump is used to back the DX pump, then the backing port must point vertically downwards (
±
20°) to reduce the risk
of contamination from the backing pump oil.
Make sure that the pump inlet and all components fitted to the pump inlet are clean and dust-free. If the pump inlet
is not kept clean, the pump-down time may be increased.
WARNING
Removal of the inlet screen will expose the risk of injury from sharp edges.
WARNING
Do not operate the pump until it is securely fixed. If the pump seizes, the stored energy of the
rotor can cause rapid movement of the pump, which may cause further damage and injury to
people.
1. EXT inlet flange
2. Inlet screen
