VEGA VEGAFLEX 83 4 … 20 mA_HART - four-wire PFA insulated - Manual (Page 20)

20
4 Mounting
VEGAFLEX 83 • 4 … 20 mA/HART - four-wire
41835-EN-130314
Fig. 11: Mounting of the sensor with inflowing medium
The reference plane for the measuring range of the sensors is the
sealing surface of the thread or flange.
Keep in mind that a min. distance must be maintained below the refer-
ence plane and possibly also at the end of the probe - measurement
in these areas is not possible (dead band). The length of the cable
can be used all the way to the end only when measuring conductive
products. These blocking distances for different mediums are listed
in chapter "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.
To compensate the normal bias voltage loss due to the seal materials,
you have to use also disc springs in addition to the flange screws for
fastening PTFE plated flanges.
The flange screws of VEGAFLEX 83 must always be tightened with
a torque of approx. 60 Nm (44 lbf ft) so that the PTFE washer seals
reliably.
Measuring range
Pressure
Torque with PTFE plated
flanges