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>500
5.
5.2.4 Connection of several tanks
Two or more tanks are connected via the
assembly surfaces by means of GRAF
special seals and basic pipes (to be
provided at construction site).
The apertures must be drilled to the
corresponding size using only the GRAF special crown bit. It must be ensured that the distance between
the tanks is at least 500 mm. The pipes must project at least 200 mm into the tanks.
5.3
Insertion and filling
The tanks must be inserted, impact-free, into
the
prepared
trench
using
suitable
equipment. To avoid deformities, the tank is
filled 1/3 with water before filling in the tank
surrounding.
Afterwards the surrounding (roundgrain
gravel, max. grain size 8/16) is then filled in
layers of max. 30 cm steps and is
compacted.
The individual layers as well as the
medial support column must be well-
compacted (manuel tamper).
Damage to
the tank must be avoided during compaction.
Mechanical compaction machines must not
be used under any circumstances. The
surrounding towards the trench must be at
least 100 mm wide.
5.4
Routing connections
All feed and overflow pipes must be routed
with a decline of at least 1% in the direction of
flow (possible, subsequent settling must be
taken into consideration in this case). If the
tank overflow is connected to a public sewer,
this must be protected against reflux by
means of a lifting station (mixed sewer) or
reflux seal (pure rainwater sewer) according
to DIN 1986.
All suction, pressure and control lines must be
routed in an empty pipe, which must be routed
as straight as possible, without bending, to the
tank with a decline. Necessary bends must be
formed using 30° moulded sections.
Important:
The
empty
pipe must
be
connected to an aperture
above
the max.
water level.
Kanal
>1%
>1%
Sewer
2. 3/3
>100
1. 1/3
