7
.
Assembling the exterior switch cabinet
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144
7.5
Connecting the air hoses
The ventilation system and the three air lift pumps must be connected to the valve strip in the switch cab-
inet.
For the lifters, hoses with 13 mm inner diameter are required, while a hose with 19 mm inner diameter is
needed for the aeration. When connecting, make sure that the hoses are attached to the correct connect-
ors.
In order to avoid confusion, the lifters, the ventilation downpipe and the four connectors on the switch
cabinet have all been colour coded:
Red feed lifter
Red hose
, 13mm
Stainless steel aeration
Blue
hose
, 19mm
Black discharge lifter
Black hose
, 13mm
Grey excess sludge lifter
White hose
, 13mm
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.
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).
We would recommend the GRAF empty pipe seal made from PE foam (art. no. 107887). Alternatively, PU
foam can be used.
7.6
Mounting the GRAF empty pipe seal made from PE foam
.
Insert the hoses from the empty pipe into the holes
in the empty pipe seal.
Push the hose through the thin top layer. A plug of
material remains stuck in the end of the hose.