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4.2. Dimensions of the intake line
In practice, the self-priming function of the pump depends due to decrease in pressure (pipe friction,
suction level) only in a certain range. In this operating range, the pump can evacuate the air out of the
suction line (for example, with initial start-up operation). The performance curve of the intake line
indicates the dependence of intake length on the intake level. The determined value is above the
represented intake line in the diagram. If the intake point is below the intake performance line, then a
charging pump (optional accessory RMF-LP) is used to ensure the intake process proceeds reliably and
with sufficient safety.
Note: The charging pump boosts the water intake pressure, so that an intake level of up to 3 m high can
be attained. This means that, the performance curve moves 3 m parallel towards down.
Sample dimensions:
Example A:
Length of suction pipe: = 12 m
Intake level: = 2.40 m (Height difference between deepest intake level and pump)
o.k. because it’s above the performance curve
Example B:
Length of suction pipe: = 18 m
Intake level: = 3.20 m (Height difference between deepest intake level and pump)
not o.k. because it’s below the performance curve
RMF-LP (Article No: 22 00 76) charging pump is required, in order to boost intake pressure to meet
the requirements)
