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Deutsch
5.962-786.0 Rev. 05 (06/13)
In order to determine the pressure loss in a pipe, the
sum of the line length and the line parts that corre-
spond to the valves is established.
This results in the length of a straight pipe wih the
same flow resistance. The value for 100 m pipe
length obtained from the table is translated into the
calculated pipe length and the result is assessed.
Thus the pressure loss for 100 m pipe in dependency
of the flow rate to the standard pipe diameter can be
read from the following diagram.
Note:
The overall pressure loss at the extraction point that
is furthest from the HD pump must
not exceed 15%
of the operating pressure!
Diagram 2
x-axle = flow rate (m³/h)
y-axle = pressure loss (bar) per 100 m piping length
see example 1:
At a flow rate of 2 m³/h the selected pipe DN 15 is too
small (pressure loss approx. 11 bar per 100 m piping
length).
Pipe DN 20 only has a pressure loss of approx. 2.2
bar per 100 m piping lenth = OK.
Otherwise the next larger pipe is to be selected for
the sections with a particularly high pressure loss.
For a final check all individual pressure losses of the
sections are added up and compared with the previ-
ously calculated 15 % of maximum overall pressure
loss.
6.4.2
Pressure loss in pipes