Pilot Operated Proportional Reducing Valve
Series VMY
4-87
VMY UK.INDD RH 17.04.2015
4
Catalogue HY11-3500/UK
Parker Hannifin Corporation
Hydraulics Group
Characteristics
Proportional pressure reducing valves of the series VMY
allow the variable adjustment of the reduced pressure
from 0 bar up to the nominal pressure.
The valve consists of a spool type main stage and a
proportionally operated pilot stage. The desired pressure
can be variably set corresponding to the command signal
specified on the amplifier. The proportional solenoid con-
verts the current of the amplifier into force on the valve
poppet of the pilot stage.
Typical applications are pressure systems, test equip-
ment, or counterweight systems. The optimum perfor-
mance can be achieved in combination with the digital
amplifier module PCD00A-400 for open loop systems or
with PWDXXA-40* for closed loop systems.
Function VMY*K06
With the proportional solenoids de-energized the main
spring forces the main spool into the neutral position. Port
A is connected to port T. Thus the reduced pressure only
depends on the back pressure in the external drain pipe
and/or the tank pressure and can accordingly be reduced
down to 0 bar. The pressure present in the P line delivers
the pilot oil to the pilot stage via a flow control valve.
When the proportional solenoid is energized, the pilot pres-
sure is increased in the pilot pressure area, and the main
spool moves against the spring until the connection P - A
opens. The regulation of the reduced pressure on connec-
tion A takes place by the constant comparison of the actual
pressure and the reference pressure of the pilot stage.
Port B has to be blocked Port X has to be blocked
Neutral position
VMY*K06
VMY*K06 VMY*K10
VMY*K06N VMY*K10
VMY*K10
The valve spool is designed so that the connection B-A
is open in the neutral position and is closed in the work-
ing position.