Brochure

Possible cause What to examine How to find the error
Curves have been made at
different speeds.
Find the speed for the catalogue
curve and the test.
Convert to the same speed and
compare again.
The catalogue curve does not
reflect the 0-series test.
Compare the 0-series test with
the catalogue curve.
If the catalogue curve and 0-series
test do not correspond, it can not
be expected that the pump
performs according to catalogue
curve.
The impeller’s outlet diameter or
outlet width is smaller than on
the 0-series test.
Measure the impeller outlet on
the 0-series pump. Adjust impeller
diameter and outlet width in
the production.
5,71429
11,4286
17,1429
22,8571
28,5714
34,2857
P1 [kW]
0
0
16.6667
33.3333
50
66.6667
83.3333
100
H[m]
0 20 40 60 80 100 120
Q [m³/h]
Curve 1
Impellere D2/D1: 99/100=0.99 Curve 1
Impellere D2/D1: 100/99=1.01010101010101 Curve 1
Curve 1
Impellere D2/D1: 99/100=0.99 Kurve 1
Impellere D2/D1: 100/99=1.01010101010101 Curve 1
0 20 40 60 80 100 120
Q [m³/h]
Make a scaling of the test where
the impeller diameter D
2
is
increased until the power matches
over most of the curve. If the
head also matches over most of
the curve, then the diameter on
the produced pump is probably
too small. Repeat the same
procedure with the impeller’s
outlet width b
2
. Scaling of D
2
and b
2
is discussed in chapter 4.5
119
Table 2: The test shows that the power consumption and head lies below
the catalogue curve.