Minimum Inlet Pressure; Maximum Inlet Pressure/ Max. Permissible Operating Pressure; Minimum Flow Rate; Electrical Data - Biral HP 3 Notice De Montage Et D'utilisation

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5.4 Minimum inlet pressure

Fig. 5
Hf
H
NPSH
Pb
Hv
The maximum suction lift «H» in metres head can be
calculated as follows:
× 10,2 – NPSH - H
H = p – H
b f
p = Barometric pressure in bar.
b
(Barometric pressure can be set to 1 bar).
In closed systems p
pressure in bar.
NPSH = Net Positive Suction Head in metres head
(to be read from the NPSH curve on page 49
at the highest flow the pump will be
delivering).
H = Friction loss in suction pipe in metres head.
f
p = Vapour pressure in metres head, see fig. C
v
on page 47
t = Liquid temperature.
m
H s = Safety margin = 0.5 ... 1,0 metres head.
If the calculated H is positive, the pump can operate at
a suction lift of maximum «H» metres head.
If the calculated H is negative, an inlet pressure of
minimum «H» metres head is required. There must be
a pressure equal to the calculated H during operation.
Example:
p = 1 bar
b
Pump type: HP 15 - .., 50 Hz
Flow rate: = 15 m 3 /h
NPSH = 1,1 metres head
(from fig. C on page 47)
H = 3,0 metres head
f
Liquid
temperature: = + 90 °C
p = 7,2 metres head
v
(from fig. C on page 47)
× 10,2 – NPSH – H
H = p – p
b f
H = 1 × 10,2 – 1,1 – 3,0 – 7,2 – 0,5 = 1,6 metres head
That means that an inlet pressure of 1,6 metres head
is required during operation.
32
– H
v s
indicates the system
b
– H (m head)
v s
5.5 Maximum inlet pressure
Figure A, page 46, shows the maximum permissible inlet
pressure. The actual inlet pressure + pressure when the
pump is running against a closed valve must always
be lower than the «maximum permissible operating
pressure».
The pumps are pressure-tested at a pressure one and
a half times greater than the value specified in fig. A,
page 46.

5.6 Minimum flow rate

Due ti the risk of overheating, the pump should not be
used at flows below the minimum flow rate.
The curve below shows the minimum flow rate as a
percentage of the nominal flow rate in relation to the
liquid temperature.
Fig. 6
Qmin
[%]
30
20
10
0
40 60 80 100 120 140 160 180
The pump must not operate against
Warning
a closed shutoff valve in the discharge
pipe.
Special version
(Air-cooled shaft seal system)

5.7 Electrical data

See motor nameplate

5.8 Frequency of starts and stops

Motor power
≤ 3 kW
4 a 30 kW
37 a 55 kW
75 kW

5.9 Dimensions and weights

Dimensions:
See fig. D, page 48
Weights:
See label on the packing

5.10 Sound level

See fig. B, page 47
t [°C]
Max. starts per hour
200
100
75
50