English (GB)
11
Uplift prevention
•
The pit design ensures that the pit is protected against uplift if
installed correctly. Requirements for uplift prevention depend
on the geotechnical conditions. They should be determined by
the engineer/construction contractor and are outside
Grundfos’ area of responsibility.
9.1 Pipe connection
Holes for inlet pipe, electrical connection and venting are to be
drilled at site.
Mark the pit where the inlet is to be. Drill the marked spot with a
hole saw. Remove all burrs from the hole. The hole saw is
available as an accessory. See table.
9.1.1 PUST04 - PUST10
Fig. 15 Drilling the inlet,
∅
400-1000 mm
9.1.2 PUST17
Drilling from the outside
If the hole diameter is greater than 150 mm or the hole is to be
drilled into a rib, drill in the centre of a rib. See fig 16.
Fig. 16 Drillilng from the outside
Drilling from the inside
Due to the circular pit shape, the pilot drill must extend beyond
the cutting edge of the hole saw by at least 23 mm. The position
of the hole is not an issue. See fig 17.
Fig. 17 Drillilng from the inside
Caution
If the hole for the pit is drilled, pay special
attention to the compaction of the backfill to
prevent uplift.
Caution
Use mechanical compacting equipment and
compact the backfill to 98-100 % proctor density.
Caution
The above requirements are minimum
requirements. Observe local regulations.
Sle
eve
Pipe diameter
Product num
be
r
Hole s
a
w [mm
]
Borehole
tolerance
[mm]
Product num
be
r
LM50/40
40
96230763
51
- 2/+ 1
96571532
LM50/50
50
96230753
60
- 2/+ 1
96571533
LM50/63
63
96571523
75
- 2/+ 1
96571534
LM50/75
75
96571527
86
- 2/+ 1
96571535
LM50/90
90
96571528
102
- 2/+ 1
96571536
L965/110
110
91716040
127
- 0/+ 2
91713756
L965/160
160
91713754
177
- 0/+ 2
91713755
LM100/200
200
91712032
212
- 2/+ 1
91712025
Pilot drill
91712026
T
M
02
93
42
24
04
We recommend to
drill the inlet in the
cylindrical, smooth
part.
Note
The hole saw must have a cup depth of minimum
90 mm.
Caution
The inlet must not be drilled in the pit close to
pipes, float switches or other parts of the pit
installation.
TM
04
9
441
42
10
T
M
04
95
73
46
10
