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TAV vent-valve
B580-65-880 Issue G
4.3.2 Fit the TAV vent-valve to the pump
1. Switch off the pump, isolate the pump controller from the electrical supply (on an EXT DX pump, isolate the
podule from the electrical supply), and wait until the pump has stopped rotating.
2. If your EXT pump has a manual vent-valve, unscrew and remove it, then continue at Step 4.
3. Refer to Figure 23. If your EXT pump does not have a manual vent-valve, fit the vent-valve adaptor (3) to a
suitable NW10 flange on your pump or vacuum system.
4. Check that the TAV vent-valve O-ring (4) is fitted and screw the TAV vent-valve into the vent-valve adaptor or
into the 1/8 inch BSP hole vacated by the manual vent-valve.
5. Connect your dry nitrogen or other inert gas supply pipeline to the M5 inlet (2) or use the riffled hose connector
(7) supplied.
6. If you vent the pump with air, fit the sintered bronze inlet-filter (1) to protect your system against the entry of
dust.
4.3.3 Electrical connection
Ensure that the electrical supply is correct. If it is not, you can damage the TAV vent-valve.
The TAV vent-valve requires a 24 V d.c. electrical supply. You can connect the TAV vent-valve to an EXC Controller,
a TIC, an EXT DX podule, or your own electrical supply. Use the following procedure to make the electrical
connections.
1. Shorten the cable to the required length.
2. Connect the cable cores to an EXC Controller (refer to the EXC Controller instruction manual), to a TIC (refer to
the TIC instruction manual), to an EXT DX podule connector plug (refer to Figure 21), or to your own electrical
supply.
3. Connect the cable screen to a suitable earth (ground) connection.
4.4 Operation
If you manually vent the pump when it is at full rotational speed and the rate of pressure rise is too high, the
pump life may be reduced. When using the manual vent valve supplied, we recommend that you either limit the
vent or only open the vent-valve after the EXT406PX pump speed has fallen to 50% of full rotational speed.
Do not vent from the backing line as this may lead to contamination. If you vent into your vacuum system and
use an oil sealed rotary backing pump, select a point upstream of the EXTPX pump, to prevent oil back-streaming
from the backing line.
Operation of the TAV vent-valve depends on how you have connected it:
z If you have connected the TAV vent-valve to an EXC Controller, use the EXC Controller to operate the
vent-valve: refer to the EXC Controller instruction manual.
Before you install the accessory, ensure that you switch off the pump and isolate the controller/
podule as described below.
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