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9 Set up measuring system
VEGADIF 85 • Profibus PA
53569-EN-230814
1. Close valve 3
2. Fill measuring system with medium.
For this purpose, open valves A, B (if available) as well as 2, 4:
Medium flows in
If necessary, clean the differential pressure lines: - with gases by
blowing out with compressed air - with liquids by rinsing.
2)
For this purpose close valve 2 and 4, i.e. block the instrument.
Then open valve 1 and 5 so that the effective pressure lines blow
out/rinse.
Close valves 1 and 5 (if available) after cleaning
3. Remove air from instrument:
Open valves 2 and 4: Medium flows in
Close valve 4: Low pressure side is closed
Open valve 3: Equalisation high and low pressure side
Briefly open valve 6 and 7, then close again: Fill the measuring
instrument completely with the medium and remove air
4. Carry out a position correction if the following conditions apply. If
the conditions are not fulfilled, then carry out the position correc
-
tion after step 6.
Conditions:
The process cannot be sealed off.
The pressure extraction points (A and B) are at the same geo
-
desic height.
5. Put measurement loop into operation:
Close valve 3: Separate high and low pressure side
Open valve 4: Connect low pressure side
Now:
Valves 1, 3, 5, 6 and 7 are closed
3)
Valves 2 and 4 are open
Valves A and B open
6. Carry out position correction, if flow can be blocked. In this case,
step 5 is not required.
2)
Arrangement with 5 valves.
3)
Valves 1, 3, 5: Configuration with 5 valves.