EN
Operating
instructions
FFU
4 Commissioning
30
8013863/10L9 /2018-08-01 © SICK AG • Fluid sensors • Germany • Subject to change without notice
4 Commissioning
4.1 Installation notes
An arrow on the measuring channel of the FFU indicates the flow measurement direction. The measu
-
ring device must be installed such that the flow passes through the measuring tube in the direction of
the arrow.
TOP
-> Outlet
BOTTOM
-> Inlet
Optimal FFU mounting orientation
To detect gases as quickly as possible, the pipeline between the storage container and the FFU
should be as short as possible. An error-free measurement can only be ensured when the pipeline
is completely full and when no liquid is being released as gas. In the case of dosing applications, it
may be useful to position the FFU as close to the dosing valve as possible, because tubing tends to
expand in diameter depending on system pressure. This can lead to deviations.
To avoid cavitations, depending on the measured liquid it can be helpful to have sufficient back-
pressure on the outlet of FFU.
If any solid particles are present, this can lead to measurement errors.
When pumps are used, the flow sensor must be mounted in the flow direction behind the pump (on
the delivery side) in order to ensure that adequate pressure will be available. The maximum pressure
rating of the FFU must be observed. In order to ensure correct volume flow measurement using the
FFU, in inlet and output paths should be straight and free of obstacles. The minimum inlet and output
paths are dependant on the nominal size:
DN10
DN15
DN20
DN25
Inlet zone
10 cm
30 cm
40 cm
40 cm
Outlet zone
0 cm
5 cm
10 cm
20 cm
Always make sure that the maximum torque of the nuts for the hydraulic connections is not overstep.
Please use the supplied seals. If you seal with teflon tape that can result in to excessive tightening
torques. We commend a maximum torque depending on the diameter of:
DN10
DN15
DN20
DN25
Torque G
2 Nm
3 Nm
4 Nm
6 Nm