Optimum Installation; Installation Tips - Grundfos DMH 251 Installation And Operating Instructions Manual

9.5 Optimum installation

1i
Fig. 10 Example of optimum installation
Pos. Components
1i Dosing tank
2i Electric agitator
3i Extraction device
4i Suction pulsation damper
5i Dosing pump
6i Relief valve
7i Pressure-loading valve
8i Pulsation damper
9i Measuring glass
10i Injection unit

9.6 Installation tips

• For easy deaeration of the dosing head, install a ball valve
(11i) with bypass line (back to the dosing tank) immediately
after the discharge valve.
• In the case of long discharge lines, install a non-return valve
(12i) in the discharge line.
11i
Fig. 11 Installation with ball valve and non-return valve
• When installing the suction line, observe the following:
– Keep the suction line as short as possible. Prevent it from
becoming tangled.
– If necessary, use swept bends instead of elbows.
– Always route the suction line up towards the suction valve.
– Avoid loops which may cause air bubbles.
Fig. 12 Installation of suction line
2i
3i
12i
8i
7i
Max. 1 m
max. 1m
6i
4i
• For non-degassing media with a viscosity similar to water, the
pump can be mounted on the tank (observe the maximum
suction lift).
• Flooded suction preferred.
• For media with a tendency to sedimentation, install the suction
line with filter (13i) so that the suction valve remains a few
millimetres above the possible level of sedimentation.
Fig. 13 Tank installation
• Note for suction-side installation: Depending on the dosing
flow and the line length, it may be necessary to install a
properly sized pulsation damper (4i) immediately before the
pump suction valve.
Observe section
using pulsation dampers
Note
request a system-specific calculation from our
calculation program.
Fig. 14 Installation with suction-side pulsation damper
• Note for discharge-side installation: Depending on the dosing
flow and the line length, it may be necessary to install a
properly sized pulsation damper (4i) on the discharge side.
9i
10i
5i
p
10i
6i
13i
9.4 Approximate values when
and, if necessary,
4i
21