15
Nozzle rod linkage 32 - EH
Connections
The connections on the block of the
feed pipe are identified as follows:
S
Oil supply to the nozzle and to the
hydraulic system of the needle
actuation. A filter with a mesh size
smaller than 50 µm should be pre-
connected. The pressure should
be kept above 20bar.
MS Here, the supply pressure of
the
nozzle is available. A pressure
gauge or a pressure sensor can
be connected to evaluate this
pressure.
R
Oil return from the nozzle. A pres-
sure or a quantity governor can be
connected for fuel oil flow control.
MR Here the return pressure of the
nozzle is available. A pressure
gauge or a pressure sensor can
be connected to evaluate this
pressure.
L
Oil return from the hydraulic
system of the needle actuation. In
principle, this oil should be allo-
wed to flow off without back pres-
sure. If this pipe is connected to a
ring main having a low overpres-
sure, it is essential to observe that
the pressure at connection „S“
must in any case be at least 20
bar higher than that pressure
which is applied at connection “L”.
Only then, the proper needle
function is ensured.
C
Here, the switching pressure of
the needle piston is available. A
pressure gauge or a pressure
sensor can be connected to eva-
luate this pressure. The pressure
is lower than the pressure at con-
nection “S” when the needle is
closed and during the switching
procedure of the needle piston.
Only during the time while the
needle is fully open, there will be a
pressure that is as high as the
pressure at connection “S”. These
properties allow the final position
of the needle to be checked
hydraulically.
When selecting the screwed connec-
tions, make sure that the ducts in the
connecting block of the feed pipe can
not be covered, not even in part. Even a
partial covering of these ducts will result
in a malfunction of the feed pipe.
