Load Sensing Controls; Ls Control With Bleed Orifice (Do Not Use With Pvg Valves); Integral Pc Function - Danfoss PVG 100 Technical Information

Technical Information
PVG 100 function

Load sensing controls

14
PVG 100 Proportional Valve Group
Legend:
1 – LS relief valve
2 – LS connection
3 – Priority spool for CF
4 – LS connection for steering unit
5 – Shuttle valve
6 –Pilot operated check valve, POC
The LS control matches system requirements for both pressure and flow in the circuit regardless of the
working pressure. Used with a closed center control valve, the pump remains in low-pressure standby
mode with zero flow until the valve is opened. The LS setting determines standby pressure.
Typical operating curve
Q max
0
0 Pressure
Most load sensing systems use parallel, closed center, control valves with special porting that allows the
highest work function pressure (LS signal) to feed back to the LS control. Margin pressure is the difference
between system pressure and the LS signal pressure. The LS control monitors margin pressure to read
system demand. A drop in margin pressure means the system needs more flow. A rise in margin pressure
tells the LS control to decrease flow.

LS control with bleed orifice (do not use with PVG valves)

The load sense signal line requires a bleed orifice to prevent high-pressure lockup of the pump control.
Most load-sensing control valves include this orifice. An optional internal bleed orifice is available, for use
with control valves that do not internally bleed the LS signal to tank.

Integral PC function

The LS control also performs as a PC control, decreasing pump flow when system pressure reaches the PC
setting. The pressure compensating function has priority over the load sensing function.
For additional system protection, install a relief valve in the pump outlet line.
520L0720 • Rev EB • Jan 2014
7 – LS line
8 – Logic cartridge for POC
9 – Pressure compensator
10 – Shock and suction valve, PVLP
11 – Main spool, PVBS
12 – Max. oil flow adjustment screws for ports A and B
13 – LS comp (LS signal sent back to compensators)
Load sensing circuit
P101 968E
P101 967