Grundfos PS.G Instrucciones De Instalación Y Funcionamiento página 8

4.2.1 Backfill
Plate compactors must not be used at a distance
Caution
of less than 30 cm from the pit wall.
• The backfill must provide sufficient support of the pit on all
sides and ensure that the load can be transferred without
detrimental point impacts or similar impacts.
• The backfill material must be compactable gravel or sand with
an even fraction size. The maximum fraction size is 32 mm.
The backfill material must not contain any stones larger than
the maximum fraction size.
• The backfilling must be carried out so that the pit is not
damaged or deformed.
• The backfill must be compacted in layers of maximum 50 cm.
Fig. 9 Compacted layers of maximum 50 cm
Compact the backfill under the inlet and outlet
pipes properly so that they are not exposed to
Note
downward loads when the backfill settles. See
fig. 10.
Fig. 10 Insufficient compaction under pipes
During backfilling, the cover must be fitted on the
Caution
pit to ensure that the pit is not deformed
(becomes oval).
8
Maximum. 50 cm
Use mechanical compacting equipment and
Caution
compact the backfill to 98-100 % proctor density.
5. Installing the valve chamber
Follow the same instructions as for the installation of the pit. See
section 4. Installing the product.
Isolating
valves
Non-return
valves
Fig. 11 Valve chamber
5.1 Connecting the pipes
Compact the backfill around the pit up to the lower part of a pipe
connection, before connecting the pipe. See fig. 10.
Before connecting the pipes, check the following:
• The pipes and the gaskets must be clean.
• The inlet pipe must be properly aligned with the pipe
connection.