Level Control Of The Drain Pit; Sensors; Pressure Sensors In District Heating Pipes; Flow Sensors In Pipe Connections - Grundfos iGRID Montage- Und Betriebsanleitung

5.1.4 Protection against buoyancy
When correctly installed, the design of the pit provides protection
against buoyancy. The requirements for buoyancy protection
depend on the geotechnical conditions. They must be determined
by the engineer or the contractor and are outside Grundfos' area of
responsibility.
The requirements below are minimum requirements.
Observe local regulations.
The buoyancy protection is determined according to Eurocode EN
1997-1, including national supplementary provision DS/EN 1997-1
DK NA: 2015.
The most unfavourable groundwater conditions for the pit are when
the water level is at ground level. This creates the highest
hydrostatic water pressure at the bottom of the pit and results in the
highest reduction in soil weight for the stabilising soil volume.
The sand volume resting on the base plate of the pit has a
stabilising effect.
5.1.5 Installing the heavy-load top cover
WARNING
Fall hazard
Death or serious personal injury
‐
Make sure to mark off the area around the solution.
‐
Follow local regulations when working at the solution.
The covers are available for all pit sizes as accessories. The heavy-
load top cover consists of a concrete ring, a concrete slab and a
metal cover. The parts are delivered separately.
To install the heavy-load top cover, do the following:
1. Lower the concrete ring onto the compacted backfill. The
particle size beneath the concrete ring must be between 2 to 20
mm.
2. Place the concrete slab on top of the concrete ring. Make
sure that there is minimum 5 cm between the concrete slab and
the pit.
3. Cover the concrete slab with asphalt, soil or another type of
cover. See the figure below.
1 2 3
Installation of heavy-load top cover
Pos. Description
1 Asphalt
2 Concrete slab
3 Heavy-load top cover
4 Pressure Zone/Temperature Zone
5 Concrete ring
The cover must be locked with special tools to prevent
unwanted access.
The foundation layer for the cover must be able to carry
the load which the cover is intended for. Carry out work
according to local regulations.
4 5
5.1.6 Installation of standard top cover
The cover is fitted from the factory on top of the iGRID Pressure
and Temperature Zone pit solution with bolts, washers and nuts.
Place the cover at least 20 cm above the terrain.
The cover must be locked with a padlock to prevent
unwanted access.
5.1.7 Installation of insulating pads
Attach the subsequently purchased insulating pads. When installing
the insulating pads after startup, see section about servicing
the solution.
Related information
9. Servicing the solution
5.1.8 Temperature sensors in district heating pipes
If the iGRID Pressure and Temperature Zone products have pre-
installed temperature sensors, make sure that the operating range
of the sensors corresponds to the expected operating temperature.
The temperature sensors are mounted in thermowells.

5.2 Level control of the drain pit

Sensor for level control of the water level in the drain pit is set by
Grundfos at delivery.

6. Sensors

6.1 Pressure sensors in district heating pipes

If the iGRID Pressure and Temperature Zone products have pre-
installed pressure sensors, make sure that the operating range of
the sensors corresponds to the expected operating pressure.

6.2 Flow sensors in pipe connections

If the iGRID Pressure and Temperature Zone products have a pre-
installed flow sensor, make sure that the operating range of the
sensor corresponds to the expected flow.
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