User Manual

3 INSTALLATION
32
OPTIWAVE 7400-24 C
www.krohne.com 12/2015 - 4003518001 - MA OPTIWAVE7400-24-R01-en
Stilling wells - general notes
Installation in tanks containing one liquid and foam
• Drill an air circulation hole (max. Ø10 mm / 0.4¨) in the stilling well above the maximum level.
• Remove the burr from the hole.
Installation in tanks containing one liquid or more without foam
• Drill an air circulation hole (max. Ø10 mm / 0.4¨) in the stilling well above the maximum level.
• Drill 1 or more liquid circulation holes in the stilling well (if there is more than 1 liquid in the
tank).
i These holes help the liquid to move freely between the stilling well and the tank.
• Remove the burr from the hole.
Stilling wells: floating roofs
If the device must be installed on a tank with a floating roof, install it in a stilling well.
Figure 3-12: Installation recommendations for standpipes (stilling wells and bypass chambers)
1 A stilling well solution
2 A bypass chamber solution
3 Air circulation hole
4 Level of the liquid
CAUTION!
• The standpipe must be electrically conductive.
• The inside diameter of the standpipe must not be more than 5 mm / 0.2 ¨ over the diameter of
the antenna (for a high-dielectric constant liquid).
• The standpipe must be straight. There must be no sudden changes in internal diameter
greater than 1 mm / 0.04
¨ .
• The standpipe must be vertical.
• Recommended surface roughness: < ± 0.1 mm / 0.004 ¨ .
• Make sure that there are no deposits at the bottom of the standpipe.
• Make sure that there is liquid in the standpipe.