IM-P309-02
MI Issue 2
15
8.2 Installation conditions
The installation location in the pipe must be selected so that the sensor is always fully
filled with the fluid and cannot run empty. This can best be guaranteed if it is installed in an
ascending pipe or drain.
The measuring principle is generally independent of the flow profile of the fluid provided no
standing vortices reach into the area where the value is measured, such as downstream
from elbows or half-open sliding valves upstream from the sensor. In these cases measures
must be taken to normalize the flow profile. Practical experience ¬has shown that in most
cases a straight inlet section of ≥ 5 x DN and an outlet section of ≥ 2 x DN of the rated width
of the sensor is sufficient. The occurrence of strong electromagnetic fields in the vicinity of
the installed sensor is not permitted.
In order to be able to perform flow and return measurements, both sides of the sensor must
be provided with a straight pipe section with the rated width of the sensor and a length of 5
DN of the rated width of the sensor. It is advisable to install actuators, such as regulating or
shut-off devices, downstream from the sensor. The flow direction is marked on the sensor
with an arrow. When mounting sensors, always observe the specified screw torques.
The electrical system can be taken into operation when the sensor and the cables have been
installed and connected. In order to prevent measuring errors caused by gas pockets in the
fluid and damage lining of the sensor caused by negative pressure, the following points must
be observed.
8.2.1 Long pipe systems
As pressure surges may occur in long pipes systems, the regulating and shut-off devices
must be installed downstream from the sensor. When mounted in vertical pipes - in particular
in flow tubes with PTFE lining and in case of higher operating temperatures - the regulating
and shut-off devices must be installed upstream from the sensor. (Danger of vacuum might
be involved!)
8.2.2 Pumps
Do not mount the sensor on the suction side of a pump. (Danger of vacuum!)
8.2.3 Bypass
In order to easily dismount, empty and clean the sensor, a bypass pipe may be installed. The
bypass with a blind flange permits the fluid pipe to be cleaned without having to dismount the
flowmeter. This is recommended for highly soiling fluids.
8.2.4 Flow tube lining
As the flow tube is lined with PTFE, the flowmeter must be installed with special care. The tube
lining is bordered at the flanges (seal). This must not be damaged or removed as it prevents
the fluid from penetrating between flange and flow tube destroying the electrode insulation.
Summary of Contents for ELM
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