ABB 266 MODBUS - Liquid Level in a Closed Tank (Wet Leg); Figure 57: Level Measurement on a Closed Tank with Wet Leg

Appendix D Additional mounting examples
266 MODBUS® multivariable transmitter User manual 2105216 Rev. AB | 97
D.3 Liquid level in a closed tank (wet leg)
The installation guidelines for liquid level measurement in a closed tank with condensable fluids (wet leg) are:
1. Mount the transmitter at the same height or below the lowest level to be measured (Figure 57).
2. Connect the + (H) side of the transmitter to the bottom of the tank.
3. Connect the - (L) side of the transmitter to the upper part of the tank.
4. Fill the vertical section (E) of the connecting line to the upper part of the tank with a compatible liquid through the dedicated
filling tee.
Where:
E = Vertical connecting line
H = High pressure flange
L = Low pressure flange
Figure 57: Level measurement on a closed tank with wet leg