GL0016P-02 Installation Guidelines for BioDisc
®
Units BF, BG, NF & NG
6
GENERAL CONCRETE SPECIFICATION
IN ACCORDANCE WITH BS EN 206-1 ( BS 8500-1)
TYPE OF MIX
(DC) DESIGN
PERMITTED TYPE OF CEMENT
BS 12 (OPC): BS 12 (RHPC): BS 4027 (SRPC)
PERMITTED TYPE OF AGGREGATE
(coarse & fine)
BS 882
NOMINAL MAXIMUM SIZE OF AGGREGATE
20 mm
GRADES: C25 /30
C25 /30
C16 /20
REINFORCED & ABOVE GROUND WITH HOLDING
DOWN BOLTS
REINFORCED (EG. FOR HIGH WATER TABLE)
UNREINFORCED (NORMAL CONDITIONS)
MINIMUM CEMENT
CONTENT
C30
C20
270 - 280 Kg/M
3
220 - 230 Kg/M
3
SLUMP CLASS
S1 (25mm)
RATE OF SAMPLING
READY MIX CONCRETE SHOULD BE SUPPLIED
COMPLETE WITH APPROPRIATE DELIVERY
TICKET IN ACCORDANCE WITH BS EN 12350-1
NOTE: STANDARD MIXES SHOULD NOT BE USED WHERE SULPHATES
OR OTHER AGGRESSIVE CHEMICALS EXIST IN GROUND WATER
5.0 BioDisc Installation
5.1 Remove the package tied to the outside of the unit. This contains a cover key.
5.2 Excavate a hole of sufficient length and width to accommodate the unit and a minimum of 150mm
concrete surround and to a depth which allows for the burial depth of the unit plus a minimum 150mm
thick concrete base.
5.3 Construct a suitable concrete base slab, a minimum of 150 mm thick, appropriate to site conditions.
In wet or unstable ground conditions it may be necessary to lay a hard-core sub-base (see notes 3.3 &
4.3). Ensure that the slab is flat and level. Allow the slab to set sufficiently to support the installed load,
but not so much as to prevent subsequent backfill bonding fully to the base.
5.4 Ensure that the slab is free of any stones or other material which could damage the unit. Lower the
unit onto the slab using suitable webbing slings and lifting equipment.
5.5 Remove the covers by undoing the locks and folding the end covers back over the inner covers before
lifting them off.
5.6 Remove the Control Panel and Owners Pack from the walkway inside the unit.
5.7 Check that the inlet and outlet orientation is correct and that the unit is level. It is essential that the unit
is installed in a level plane to avoid undue stress on the bearings.
The rotor shaft must be level end to end, to within ±3mm, measured at the bearing caps or directly on
the shaft.
The unit must also be level to within ±5mm from side to side, measured at the GRP walkway on either
side of the rotor.
If necessary, lift the unit off the base and apply further concrete as needed to level up.
Note : The top flange of the BioDisc should not be used for levelling as manufacturing tolerances may
result in it not being parallel with the rotor shaft.
5.8 It is essential that levels given above are checked regularly throughout the installation process. Should
the unit become out of level, immediate remedial action is advised, to maintain the unit within the
levels stated in section 5.7.
5.9 Pour no more than 1 metre depth of water into both primary (inlet) chambers and the final (outlet)
chamber ensuring that there is never more than 250mm difference in water level between any of the
sections.
