Karcher IV 100 - 55 M B1 - Manual (Page 15)

English 5.906-587.0 Rev. 00 (05/14) 15
In an ideal line network no losses would occur and the nec-
essary suction unit could be determined with the two pa-
rameters air speed and volume flow. In the real line
network, however, losses are created due to resistances
and turbulences. These must be calculated as pressure
losses in the pipeline network in order to determine the re-
quired suction performance.
With branched pipelines only the way that causes the
greatest pressure loss (main run) must be determined. For
the calculation of the pressure loss the overall length is di-
vided in sections with the same air quantity (volume flow)
and the same diameter.
A Section 20 m pipeline
B Section 5 m pipeline
C Section 10 m hose
In the individual sections the pressure loss is calculated in-
dividually and then added up to the overall pressure loss.
When calculating the overall pressure loss it must be ob-
served which vacuuming points are operated simultane-
ously.
For the determination of the pressure differences per sec-
tion the branch lines do not need to be calculated as they
are not relevant for the overall pressure loss of the system.
Branch lines must be closed if they are not in operation
(e.g. with sliders, caps, etc.) so that no false air (see Chap-
ter "Use and setting of the false air valve") is sucked out.
Note
A security of 10 to 20% should be present as the volume
flows can not always be adjusted in the way they have
been calculated and to cover imponderables.
10 Calculation of the pressure loss