VEGA VEGADIF 34 … 51 - Manual (Page 44)

44 VEGADIF 34 … 51
20094-EN-030731
Installation connections
Connection of the transmitter to the valve
block
The connection of the transmitter is normally
made just before commissioning. Generally
seal rings made of PTFE as well as four
screws are supplied with the valve block. Flat
seals are used on both process connections
of VEGADIF.
Procedure:
1 Push both seal rings into the grooves of the
valve block (it is always recommended that
two new PTFE seals be used every time the
transmitter is connected to the valve block).
2 Screw the transmitter carefully onto the
valve block (4 screws).
3 Tighten the screws crosswise (recom-
mended torque 6 - 8 Nm).
1 Inlet valves
2 Transmitter
3 Vent or drain valves
4 Block valves
5 Pressure tapping point
6 Ventilation screw
For differential pressure measurements refer-
enced to the open atmosphere, the impulse
line must be connected to the plus side of the
transmitter. The minus side remains open to
the atmosphere. In case of extremely dirty
atmospheres, we recommend using a filter on
the minus side or an open tube bent down.
This protects the minus side against buildup.
4 4
1 1
5
6 6
+ -
3
2
5.3 Differential pressure
measurement
Installation connection for liquids
If the pressure of a flowing material is to be
measured in a pipe, the pressure tapping
points must be located where there is steady
flow. The impulse lines must be installed with
continuous gradient
≥
1 : 10 (i.e. 10 cm per
meter).
The recommended installation position of the
transmitter is below the pressure tapping
points.
With products containing solid particles, the
pressure tapping points must be positioned
on top of the pipelines.