Grundfos NK Montage- Und Betriebsanleitung Seite 17

Codes for stuffing box
Pos. Code Description
1 S Stuffing box
Cooling method
2 N Without cooling
Barrier fluid
E With internal barrier fluid
3 F With external barrier fluid
O Without barrier fluid
Materials
PTFE-impregnated fibre packing rings and
A
EPDM O-rings in pump housing
Graphite-PTFE packing rings and EPDM
B
O-rings in pump housing
4
PTFE-impregnated fibre packing rings and
C
FKM O-rings in pump housing
Graphite-PTFE packing rings and FKM O-rings
D
in pump housing
4.3 Impeller diameter
At the customer's request, the impeller diameter may have been
changed to allow the pump to match a specified duty point.
This means that the actual impeller diameter differs from the
standard diameters stated in sales catalogues, data sheets, etc.
The actual impeller diameter can be found on the pump
nameplate.
4.4 Pumped liquids
Clean, thin, non-explosive liquids without solid particles or fibres.
The liquid must not attack the pump materials chemically.
When pumping liquids with a density and/or viscosity higher than
that of water, motors with correspondingly higher outputs must be
used, if required.
O-rings and the shaft seal chosen must be suitable for the liquid
to be pumped.
Special shaft seals may be required if the pump is used for
pumping treated water at temperatures above 80 °C containing
additives to prevent system corrosion, calcareous deposits, etc.,
for instance in heating and ventilating systems.
Another type of shaft seal may also be required for the pumping
of glycol-containing liquids.
For heating systems, the water quality should meet VDI 2035.
Contact Grundfos for further information.
5. Technical data
5.1 Ambient temperature
The ambient temperature and the installation altitude are
important factors for the motor life, as they affect the life of the
bearings and insulation system.
Maximum ambient temperature:
• EFF2 motors: +40 °C.
• EFF1 motors: +60 °C.
If the ambient temperature exceeds +40 °C (+60 °C), or the motor
is installed more than 1000 m (3500 m) above sea level, the
motor must not be fully loaded due to the low density and
consequently low cooling effect of the air. In such cases, it may
be necessary to use a motor with a higher output.
P2
[%]
100
90
80
70
60
50
20 25 30 35 40 45 50 55 60 65 70 75 80
1000 2250
Motor P2 in relation to temperature/altitude
Fig. 6
5.2 Liquid temperature
-25 °C to +140 °C.
The maximum liquid temperature is stated on the pump
nameplate. It depends on the shaft seal chosen.
For pump housing of cast iron EN-GJL-250 local regulations may
not allow liquid temperatures above +120 °C.
5.3 Operating pressure
The maximum operating pressure is stated on the nameplate.
NK:
Maximum 1.6 MPa (16 bar).
DN 200: 1 MPa (10 bar).
NKG:
Maximum 1.6 MPa (16 bar).
5.4 Minimum inlet pressure
According to the NPSH curve of the pump (see page 725) +
a safety margin of minimum 0.5 m head.
The procedure for the calculation of the minimum inlet pressure is
shown in 13. Calculation of minimum inlet pressure.
5.5 Maximum inlet pressure
The actual inlet pressure + pump pressure against a closed valve
must always be lower than the maximum permissible operating
pressure.
5.6 Minimum flow rate
The minimum flow rate must be at least 10 % of the maximum
flow rate. The flow rate and head are stated on the pump
nameplate.
5.7 Maximum flow rate
The maximum flow rate must not exceed the values stated for the
individual pump on page 713, as otherwise there is a risk of for
instance cavitation and overload.
5.8 Electrical data
See the motor nameplate.
5.9 Weight
See label on the packing.
5.10 Sound level
See table on page 711.
The values stated are maximum values, including the upper
tolerance of 3 dB according to ISO 4871.
EFF 1
EFF 2
t [°C]
3500 4750 m
17