Pag. 12 of 52
- Installation
7. INSTALLATION
7.1 Measuring point Selection
The transducers must be mounted on a pipe section which allows to respect the minimum distance between the element
of resistance to flow, such as curves or derivations, and the measuring point. See the following table
Flow resistance element
Upstream side
Downstream side
90° curves
T junction
Adaptors
Valves
Pumps
In the event that the minimum values shown in table 4 can not be met, it is necessary to adopt every mechanical
devices to mitigate the flow turbulence and improve the homogeneity of the flow velocity in the pipe. One of the best
devices is the transducers upstream installation of a fluid threads rectifier, which allows to have a straight section
length of the pipe less than indicated.
The pipe where the transducers are placed must have the following characteristics:
- smooth surface without rust or other surface deterioration;
- circular cross section
The ideal points for the transducer positioning are:
- hydraulic circuit lowest point (fig.12-a);
- vertical pipes with the upward flow (fig.12-b);
- inclined pipes with the upward flow (fig.12-c);
- vertical open drain pipes with a section restriction to avoid sudden pipe emptying
during flow measurement (fig.13)
Correct transducers positioning example
Correct transducers positioning example
Tab. 4
Fig. 12
Fig. 13
