Siemens SITRANS LG240 Operating Instructions Manual page 17

Pressure
Lateral installation
Rod extension
Torque with PTFE plated
flanges
PBD-51041037
products. These dead zones for different mediums are listed in chap-
ter "Technical data". Keep in mind for the adjustment that the default
setting for the measuring range refers to water.
The process fitting must be sealed if there is gauge or low pressure in
the vessel. Before use, check if the seal material is resistant against
the measured product and the process temperature.
The max. permissible pressure is specified in chapter "Technical
data" or on the type label of the sensor.
In case of difficult installation conditions, the probe can also be
mounted laterally. For this, adapt the rod with rod extensions or
angled segments.
To compensate for the resulting changes in signal runtime, let the
instrument determine the probe length automatically.
The determined probe length can deviate from the actual probe
length when using curved or angled segments.
If internal installations such as struts, ladders, etc. are present on the
vessel wall, the measuring probe should be mounted at least 300 mm
(11.81 in) away from the vessel wall.
You can find further information in the supplementary instructions of
the rod extension.
In case of difficult installation conditions, for example in a socket, the
probe can be suitably adapted with a rod extension.
To compensate for the resulting changes in signal runtime, let the
instrument determine the probe length automatically.
You can find further information in the supplementary instructions of
the rod and cable components.
The PTFE washer of the antenna encapsulation serves also as
process seal.
To compensate the normal prestress loss due to the seal materials,
you have to use also disc springs in addition to the flange screws for
fastening PTFE plated flanges.
We recommend flexible retaining washers (e.g. Schnorr VS or S) or
detent edged rings (e.g. Gross VS KD).
Fig. 9: Use of disc springs
1 Single disc spring
2 Laminated disc spring
The flange screws of SITRANS LG240 must be tightened with a
torque of approx. 60 Nm (44 lbf ft) so that the PTFE washer seals
reliably.
SITRANS LG240 - Operating Instructions
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