Deltabar S FMD77, FMD78, PMD75 with FOUNDATION Fieldbus
Commissioning
Hauser
67
7.6
Flow measurement
7.6.1
Preparatory steps
• The Deltabar S PMD75 is usually used for flow measurement.
• Before calibrating the Deltabar S, the pressure piping must be cleaned and the device filled
with fluid.
See the following table.
Valves
Meaning
Preferred installation
1
Close 3.
P01-xMD7xxxx-11-xx-xx-xx-002
Fig. 36:
Above: preferred installation for gases
Below: preferred installation for liquids
I
Deltabar S PMD75
II
Three-way valve manifold
III
Separator
1, 5
Drain valves
2, 4
Inlet valves
3
Equalizing valve
6, 7
Vent valves on Deltabar S
A, B
Shutoff valves
2
Fill measuring system with fluid.
Open A, B, 2, 4.
Fluid flows in.
3
Clean pressure piping if necessary
1)
:
– by blowing out with compressed air in the case of
gases
– by rinsing out in the case of liquids.
1)
For arrangement with 5 valves
Close 2 and 4.
Block off device.
Open 1 and 5.
Blow out/rinse out
pressure piping.
Close 1 and 5.
Close valves after cleaning.
4
Vent device.
Open 2 and 4.
Introduce fluid.
Close 4.
Close negative side.
Open 3.
Balance positive and
negative side.
Open 6 and 7 briefly, then
close them again.
Fill device completely with
fluid and remove air.
5
Carry out pos. zero adjustment if the following
conditions are met. If the conditions are not met, then do
not carry out the pos. zero adjustment until after step 6.
Conditions:
– The process cannot be blocked off.
– The tapping points (A and B) are at the same geodetic
height.
6
Set measuring point to operation.
Close 3.
Shut off positive side from
negative side.
Open 4.
Connect negative side.
Now
– 1
, 6 and 7 are closed.
– 2 and 4 are open.
– A and B are open (if present).
7
Carry out pos. zero adjustment if the flow can be blocked
off. In this case, step 5 is not applicable.
69,
8
Carry out calibration.
I
II
+
–
–
+
6
6
7
7
–
+
3
2
4
A
B
A
B
+
1
5
2
4
3
II
I
III
III
Содержание Deltabar S FMD77
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