Unloader Valve Function - Nilfisk-ALTO Neptune PE Service Manual

Unloader mounted on pump
Unloader disassembled
NEPTUNE PE-DE_en_Ver.1.0_October 2010
Function
Unloader valve function NEPTUNE 5-85Pe AND 5-51DE
Unloader function:
On the assumption that the black handle
(adjustment handle) on the unloader is turned all
the way to max. pressure (clockwise).
When the pump is running the unloader piston (2)
is pressed down it its seat (1), and all the water
volume is going through the gun and out to the
high pressure nozzle.
When the gun is released (no water flow out), the
pressure in the unloader will rise, and the in-
creased pressure will overcome the adjusted ten-
sion of the unloader spring (6), and the unloader
piston (2) will be lifted up from its seat.
Water will now return through the seat (1) to the
suction side of the pump (by-pass) mode.
Jetwash Direct ltd
D
34