Bentone BF1 - LE-S System; Purging

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Bentone BF1
General
6.2.6 LE-S System
Note!
The *LE-S pump has an integrated check-valve function at the solenoid
valve, allowing the oil pressure to expand backwards during standstill. The
desired function of avoiding the formation of drops on the nozzle can only be
achieved by using both the LE-S pump and the LE valve built into the FPHB-
LE preheater.
The system is only used on the BFP pump fitted with a solenoid valve.The
pumps are given a different designation, e.g. BFP 41L3 LE-S, but do not
differ on the outside from the normal BFP pump.
BFP LE-S pumps cannot be converted into standard pumps, and the stan-
dard BFP pump cannot be converted to the LE-S system.
The LE valve must be fitted when using the LE-S pump. The LE valve may
not be excluded unless a BFP standard pump without the LE-S
function is used instead.
The check valve **B allows the oil trapped between solenoid valve NC and
the LE valve in the preheater to expand backwards in the system to the
return port.
The cut-off valve does not cause any extra pressure drop, i.e. at a pump
pressure of 10 bar the spraying pressure will also be 10 bar.
6.2.7 Purging
Purging air is only necessary in single-pipe systems. In two-pipe systems the
pump purges air automatically through the return line.