Edwards EXT200/200H GCMS, Инструкция по эксплуатации, Страница: 23 / 38

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Installation
B756-01-880 Issue K
Use the Edwards trapped O-ring supplied with the pump and use a minimum of four fixing bolts to connect the inlet
flange of the pump to the vacuum system. M8 bolts should be tightened to a torque of 5-6 Nm.
Figure 7 - Mounting attitude range of an EXT split flow pump
3.3.4 Backing connection
Use suitable vacuum tubing and connectors to connect the NW flange of the backing port to the backing pump. If
necessary, use flexible pipe or bellows to reduce the transmission of vibration from the backing pump to the EXT Split
Flow Pump.
Edwards recommends using an Edwards RV Backing Pump. The minimum size of the backing pump required is given
in
Table 4 . A larger backing pump may be required if the pump is run at a high inlet pressure. The EXT70/200H and
EXT200/200H Split Flow Pumps are also suitable for use with diaphragm backing pumps although the effect of higher
backing pressure on the pump’s performance and cooling requirements should be noted (see
Table 1 and
Section 3.6 ).
CAUTION
Do not use the EXT Split Flow Pump with a backing pressure below 5 x 10
-4
mbar (5 x 10
-2
Pa). Lower backing
pressures will increase the evaporation rate of the lubricating oil and so will reduce the life of the bearings.
WARNING
The customer must ensure safe ducting of the backing line if oil mist or hazardous substances are
present.
WARNING
Split Flow Pumps must not be operated, or vented from a positive pressure gas supply, with a
restricted/blocked backing line.
Use suitable vacuum tubing and connectors to connect the NW25 flange of the backing port to the
backing pump. If necessary, use flexible pipe or bellows to reduce the transmission of vibration
from the backing pump to the Split Flow Pump.