Example with result in feet
Pb = 33.46 ft.
Pump type: CR 95.
Flow rate: 418 GPM.
NPSH (see the NPSH curve in the appendix):
11.48 ft head.
Hf = 9.84 ft head.
Liquid temperature: +140 °F.
Hv (see the appendix): 6.9 ft head.
H = Pb - NPSH - Hf - Hv [ft head].
H = 33.46 - 11.48 - 9.84 - 6.9 = 5.24 ft. This
means that the pump can operate at a suction lift
of maximum 5.24 ft head.
Pressure in psi:
H x 0.433 x specific gravity of pumped fluid
5.24 x 0.433 x 1 = 2.27 psi.
Example with result in meters
Pb = 1 bar
Pump type: CR 95
Flow rate: 95 m
3
/h
NPSH (see the NPSH curve in the appendix): 3.5
m head.
Hf = 3.0 m head.
Liquid temperature: +60 °C.
Hv (see the appendix): 2.1 m head.
H = Pb x 10.2 - NPSH - Hf - Hv [ft head].
H = 1 x 10.2 - 3.5 - 3.0 - 2.1 = 1.6 m head.
This means that the pump can operate at a
suction lift of maximum 1.6 m head.
Pressure in bar: 1.6 x 0.0981 = 0.157 bar.
Pressure in kPa: 1.6 x 9.81 = 15.7 kPa.
12.1.5 Maximum permissible inlet pressure
The table in the appendix states the maximum
permissible inlet pressure for vertically mounted
pumps. However, the actual inlet pr the
maximum pump pressure at no flow must always
be lower than the maximum permissible system
pressure which is stated on the pump nameplate.
For identification of the nameplate data, see the
section on the nameplate.
The pumps are pressure-tested at a pressure of
1.5 times the maximum permissible system
pressure.
12.1.6 Minimum flow rate
WARNING
Too high pressure and leakage
Death or serious personal injury
‐
Do not run the pump against a
closed outlet valve.
Due to the risk of overheating, do not use the
pump at flows below the minimum flow rate.
The curves below show the minimum flow rate as
a percentage of the rated flow rate in relation to
the liquid temperature.
- - - - = air-cooled top.
104
140
176
212
248
284
320
356
0
10
20
30
Qmin
(40)
(60)
(80)
(120) (140) (160) (180)
(100)
[ % ]
[ °F ]
[ (°C) ]
t
TM070517
Minimum flow rate in percentage of nominal flow
12.1.7 Frequency of starts and stops
See data in the instructions that apply to the
motor.
12.2 Electrical data
See the motor nameplate.
12.3 Dimensions and weights
Dimensions: see the appendix.
Weights: see the label on the packing.
13. Disposing of the product
This product or parts of it must be disposed of in
an environmentally sound way.
1. Use the public or private waste collection
service.
2. If this is not possible, contact the nearest
Grundfos company or service workshop.
The crossed-out wheelie bin
symbol on a product means
that it must be disposed of
separately from household
waste. When a product
marked with this symbol
reaches its end of life, take it
to a collection point
designated by the local
waste disposal authorities.
The separate collection and
recycling of such products
will help protect the
environment and human
health.
See also end-of-life information at
www.grundfos.com/product-recycling
31
English (US)
