Starting Up The Product; Precharge Pressure - Grundfos GT-U+ Montage- Und Betriebsanleitung

3.2.1 Foundation
Place the tank on its frame in a vertical position on a
solid and level floor or foundation.
Secure the tank to the floor or foundation by means
of bolts. Use bolts, washers and nuts that are
suitable for the surface of the floor or base frame.
Use all bolt holes in the frame when securing the
tank.
Fig. 1 Example of floor installation
3.2.2 Lifting the tank
DANGER
Crushing hazard
Death or serious personal injury
- Use a lifting crane or similar lifting
equipment.
- Wear safety shoes when handling the
pump.
Use all lifting eyes on the tank when lifting
the tank.
Be careful not to damage the tank during handling.
1
Fig. 2 Lifting the tank
Pos. Description
1 Correct lifting
2 Incorrect lifting
3.2.3 Relief valve
We recommend to install a suitable pressure-relief
valve.
3.2.4 Isolating valve
We recommend to install an isolating valve between
the pressure tank and pipe so you can isolate the
pressure tank for service.
Fig. 3
3.3 Multiple tank installation
Tanks must be installed on a header to ensure all
tanks receive equal and balanced pressure.
Adjust the precharge pressure of each tank as
described in section
pressure.

4. Starting up the product

4.1 Precharge pressure

Correct precharge pressure is required for proper
2
tank performance.
The precharge pressure must be adjusted according
to the actual application and the installed pump.
Recommended precharge pressures:
• 0.9 x cut-in for fixed-speed pumps with a
differential pressure < 2 bar (30 psi).
• 0.7 x cut-out for fixed-speed pumps with a
differential pressure > 2 bar (30 psi).
• 0.7 x setpoint for variable-speed pumps.
Isolating valve
All tanks must have the same precharge
pressure for the system to function
properly.
4.2 Adjusting the precharge
The difference between the precharge
pressure and the system pressure must
never exceed 4 bar (58 psi). If system
pressure needs to be lowered, the tank
must be isolated or emptied.
7