Weight; Stroke Volume; Materials; Data Of Contact Pressure Gauge For Diaphragm Leakage Detection (Optional) - Grundfos DMH 25 Série Notice D'installation Et De Fonctionnement

5.3 Weight

Dosing head
Pump type
material
PVC, PP, PVDF
DMH 251
Stainless steel
1.4571, 2.4610
PVC, PP, PVDF
DMH 252
Stainless steel
1.4571, 2.4610
PVC, PP, PVDF
DMH 253
Stainless steel
1.4571, 2.4610
PVC, PP, PVDF
DMH 254
Stainless steel
1.4571, 2.4610
PVC, PP, PVDF
DMH 255
Stainless steel
1.4571, 2.4610
PVC, PP, PVDF
DMH 257
Stainless steel
1.4571, 2.4610

5.4 Stroke volume

Stroke volume [cm
Pump type
4 bar
DMH 251 -
DMH 252 -
DMH 253 -
DMH 254 -
DMH 255 -
DMH 257 171

5.5 Materials

Pump housing material
• Pump housing: Al 226.
AR control unit enclosure
• Upper part of enclosure: PPO blend
• Lower part of enclosure: aluminium.
Warning
Observe the chemical manufacturer's safety
instructions when handling chemicals!
Make sure that the pump is suitable for the actual
dosing medium!
The resistance of the parts that come into contact
with the media depends on the media, media
temperature and operating pressure. Ensure that
Caution
parts in contact with the media are chemically
resistant to the dosing medium under operating
conditions!
Further information on resistance with regard to the
media, media temperature and operating pressure is
Note
available on request.
20
Weight [kg]
Single Double
pump pump
11 13
13 17
11 13
13 17
12 17
14 21
27 32
32 42
55 63
65 83
56 88
68 112
3
]
10 bar 16 bar 25 bar
3.5 3.1 2.9
6.4 6.3 -
11.3 - -
31.6 30 -
60 - -
131 - -
5.6 Data of contact pressure gauge for diaphragm
leakage detection (optional)
Following data is not valid for contact pressure
Note
gauges in explosion-proof version.
The contact pressure gauge has a reed switch with electrically
isolated contact output, maximum switching power 10 W for DC
current or 10 VA for AC current. The maximum switching voltage
is 75 V for DC current or 50 V for AC current, maximum switching
current 0.5 A.
The switching function is set up as an NC contact, i.e. if the
diaphragm breaks, the current circuit is interrupted.
The pressure gauge has a 2-metre cable.

6. Installation

6.1 General information on installation

Warning
Observe the specifications for the installation
location and range of applications described in
section 3. Technical
Warning
Faults, incorrect operation or faults on the pump or
system can, for example, lead to excessive or
insufficient dosing, or the permissible pressure may
be exceeded. Consequential faults or damage must
be evaluated by the operator and appropriate
precautions must be taken to avoid them!
Warning
Risk of hot surfaces!
Pumps with AC motors may become hot.
Allow a minimum space of 100 mm to the fan cover!
A positive pressure difference of at least 2 bar is
required between the suction valve and the
discharge valve in order for the dosing pump to
operate correctly.
Note
If the total counter-pressure (at the dosing point) and
geodetic height difference between the suction valve
and the dosing point is less than 2 bar (20 m WC), a
pressure-loading valve must be installed immediately
before the dosing point.

6.2 Installation location

6.2.1 Space required for operation and maintenance
The pump must be installed in a position where it is
easily accessible during operation and maintenance
Note
work.
Maintenance work on the dosing head and the valves must be
carried out regularly.
• Provide sufficient space for removing the dosing head and the
valves.
6.2.2 Permissible ambient influences
See section 3.9 Ambient and operating
The installation site must be under cover!
Note
Do not install outdoors!
6.2.3 Mounting surface
The pump must be mounted on a flat surface.

6.3 Mounting

• Mount the pump on a console or pump foundation using four
screws.
Note The flow must run in the opposite direction to gravity!
data.
conditions.