Procedure
Pressure transmitter above the differential pressure
transducer
Pressure transmitter below the differential pressure
transducer
① Pressure transmitter ⑦ Blowout valves
② Stabilizing valve ⑧ Condensate vessels (optional)
③, ④ Differential pressure valves ⑨ Differential pressure transducer
⑤ Differential pressure lines ⑩ 3-way valve manifold
⑥ Shut-off valves
To commission the pressure transmitter for gases, proceed as follows:
1. Open both the shut-off valves ⑥ at the pressure tapping point.
2. Open the stabilizing valve ②.
3. Open the differential pressure valve (③ or ④).
4. Check and, if necessary, correct the zero point when the start-of-scale value is 0 bar (4 mA).
5. Close the stabilizing valve ②.
6. Open the other differential pressure valve (③ or ④).
Commissioning
6.5 Differential pressure and flow rate
SITRANS P320/P420 with 4 to 20 mA/HART
Compact Operating Instructions, 09/2018, A5E38874562-AB 49