Graf oneAdvanced Commercial Notice D'installation page 33

7 Routing the air hoses
7.1 Connecting the air hoses
The ventilation system and the air lift pumps must be connected to the valve strip in the switch cabinet.
When connecting, make sure that the hoses are attached to the correct connectors. In order to avoid con-
fusion, the lifters, the ventilation downpipe and the four connectors on the switch cabinet have all been
colour coded:
Red feed lifter
Stainless steel ventilation
Black discharge lifter
Grey excess sludge lifter
As a general rule, the connections with the same colours must be attached to one another and fixed with
hose clamps. Hoses can be supplied in the relevant colours.
7.2 Empty pipe seal with PU foam
7 Routing the air hoses
Once the hoses have been laid and attached, the empty pipe must be
sealed in order to avoid gas exchange between the wastewater treat-
ment system and the surroundings of the cabinet (moisture, odours).
Filling the empty pipe with PU foam may give rise to small leaks. The GRAF
empty pipe seal of PE foam is recommended.
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Red hose
Blue hose
Black hose
White (transparent) hose
The hose surfaces and pipe walls must be cleaned
roughly and wetted slightly with water.
When filling the hoses with PU foam, make sure
that each of them is covered on all sides. For bet-
ter filling and enveloping, the hoses should be
moved slightly in the longitudinal direction.