Cerabar M, Deltabar M, Deltapilot M / 4...20 mA HART
Commissioning
Hauser
75
6.9
Differential pressure measurement (Deltabar M)
6.9.1
Preparatory steps
!
Note!
• Before calibrating the device, the impulse piping must be cleaned and filled with fluid.
See the
following table.
Valves
Meaning
Preferred installation
1
Close 3.
P01-PMD55xxx-11-xx-xx-xx-013
Above: preferred installation for gases
Below: preferred installation for liquids
I
Deltabar M
II
Three-valve manifold
III
Separator
1, 5
Drain valves
2, 4
Inlet valves
3
Equalising valve
6, 7
Vent valves on Deltabar M
A, B
Shut-off valve
2
Fill measuring system with fluid.
Open A, B, 2, 4.
Fluid flows in.
3
Clean impulse 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 impulse
piping.
Close 1 and 5.
Close valves after cleaning.
4
Vent device.
Open 2 and 4.
Introduce fluid.
Close 4.
Close low-pressure side.
Open 3.
Balance positive and low-
pressure side.
Open 6 and 7 briefly, then
close them again.
Fill device completely with
fluid and remove air.
5
Set measuring point in operation.
Close 3.
Shut off high-pressure side
from low-pressure side.
Open 4.
Connect low-pressure side.
Now
– 1
, 3, 5
, 6 and 7 are closed.
– 2 and 4 are open.
– A and B open (if present).
6
Carry out calibration if necessary.
See also page 76,
section 6.6.2.
I
II
+
–
–
P2
+
P1
6
7
–
P2
+
P1
6
7
3
2
4
A
B
A
B
+
1
5
2
4
3
II
I
III
III
