Functionality Of A Flow Control Spool - Danfoss PVG 32 Application Manual

Application Guide
Using flow or pressure control spools

Functionality of a flow control spool

© Danfoss | Feb 2017
Normally, FC spools are used for most applications. The basic principle is shown in
spool on page 5. The main spool works as a variable orifice controlling flow P>A/B and A/B>T,
simultaneously.
Basic principle of an FC spool
Pl is the hydraulic load pressure (determined by the size of the load) that acts in parallel with a spring on
one side of the compensator. The other side of the compensator is connected to the Pc pressure. The Pc
pressure will remain 7 bar higher than Pl. This also means that flow out of the valve is always directly
proportional to the opening area of the main spool. This can be seen in
position of the spool will always give the same amount of flow out of the valve independent of load
changes on the work ports.
FC spool
Basic principle of an FC
FC spool on page 5. A certain
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