Installation
Proline Promag 53 PROFIBUS DP/PA
22
Hauser
3.2.7
Adapters
Suitable adapters to DIN EN 545 (double-flange reducers) can be used to install the sensor in larger-
diameter pipes. The resultant increase in the rate of flow improves measuring accuracy with very
slow-moving fluids.
The nomogram shown here can be used to calculate the pressure loss caused by cross-section
reduction.
!
Note!
The nomogram applies to liquids of viscosity similar to water.
1.
Calculate the ratio of the diameters d/D.
2.
From the nomogram, read off the pressure loss as a function of flow velocity (
downstream
from
the reduction) and the d/D ratio.
a0003213
Fig. 16:
Pressure loss due to adapters
3.2.8
Nominal diameter and flow rate
The diameter of the pipe and the flow rate determine the nominal diameter of the sensor. The
optimum velocity of flow is between 2 and 3 m/s. The velocity of flow (v) also has to be adjusted
to the physical properties of the fluid:
• v < 2 m/s: for abrasive fluids
• v > 2 m/s: for accretive fluids
!
Note!
Flow velocity can be increased, if necessary, by reducing the nominal diameter of the sensor using
adapters.
100
10
0.5
d / D
[mbar]
0.6
0.7
0.8
0.9
1 m/s
2 m/s
3 m/s
4 m/s
5 m/s
6 m/s
7 m/s
8 m/s
1
D
d
max. 8°