Danfoss PVG 32 Application Guide

As mentioned in the beginning of this document, instability is seen in systems that use FC spools in high
inertia systems. An example of such a system is shown in Natural oscillation example on page 6.
Natural oscillation example
A Pressure
B Time
Yellow line Pl
Red line Pc
At any given time, the compensator will try to keep the pressure drop across the main spool at the same
level and follow the pressure oscillations from the actuator attached to the valve. When the load pressure
is changing, the compensator will follow this frequency to keep the amount of flow from the valve at the
same level as the pressure.
So an FC spool offers no damping of the system but maintains a constant flow.
Application Guide
Using flow or pressure control spools
Flow control spools in oscillating systems
6 |
©
Danfoss | Feb 2017 AB00000079en-US0101

Danfoss PVG 32 Specifications

General

Category	Control Unit
Maximum working pressure	350 bar
Size	32
Type	Proportional Valve
Maximum operating pressure	420 bar
Porting pattern	ISO 4401
Electrical connection	AMP