8.1.3 Installation with metering pumps with self-degassing (SEK type)
CAUTION!
– All the installation and safety information for
metering pumps without self-degassing also
apply.
–
Do not exceed the maximum values for priming
lift, priming pressure and viscosity of the feed
chemical.
– Do not allow the suction side line cross-section
to exceed the line cross-section on the suction
valve.
Information about priming pressure
n Make sure that the pressure in the return line is at least equal
to the priming pressure on the suction side.
n Back pressure in the return line restricts the degassing func‐
tion.
n In contrast, it is possible to operate the pump with back pres‐
sure in the return line and atmospheric pressure on the suction
side.
A return line is also connected in addition to the suction and pres‐
sure line.
n The return line is connected to the vertical valve on the upper
side of the liquid end. It is factory-labelled with a red sleeve -
see Fig. 11.
n The pressure line is connected to the horizontal valve.
1. Attach the hose line to the return hose sleeve or to the liquid
end vent valve. PVC hose, soft, 6x4 mm is recommended.
2. Feed the free end of the return line into the supply tank.
3. SEK only: Insert the return line into the anti-kink device on
the vent valve and pull it downwards until the anti-kink device
engages.
INFORMATION: The anti-kink device prevents the return line
from kinking, avoiding the risk of self-degassing failure.
4. Shorten the return line so that it is not immersed in the feed
chemical in the supply tank.
Safety information
Installation of the return line
Installation, hydraulic
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