Siemens SITRANS SL - Purging Set-Up

Installing
4.5 Purging
SITRANS SL
66 Operating Instructions, 12/2010, A5E01132948-04
4.5.3 Purging set-up
Mount the purging connectors according to the following procedure (see the following figure):
1. Remove the plugs from the RTU/TTU and the process flange.
2. Mount the needle valves and the exit aperture.
3. Attach a piece of 6 mm tubing to the needle valves and route it to an appropriate purging
gas source.
CAUTION
Make sure that the purge gas quality is sufficient to avoid rapid degradation of the
visibility in the optical path.
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
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 
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① Purging tube ⑤ RTU or TTU (Receiver or transmitter tube unit)
② Process flange ⑥ RHU or THU (Receiver or transmitter house unit))
③ Process purging input ⑦ Needle valves
④ Sensor purging output ⑧ PI (Process interface)
Figure 4-15 Sensor purging input with needle valve
Note
When using a plastic tube for connecting the purge gas supply, be sure to use the supplied
rigid metal insert.