Lull 6K Service Manual User Manual
Page 212
Supply, Pressure, and Return Hydraulics
5-68
Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K
Logic Valve
The Logic (LC) valve opens and closes dependent upon a pilot signal from
the Pilot Unloading (PU) valve.
Pilot Directional Valve
The Pilot Directional (PD) valve allows oil downstream to the pressure
reducing valve once the engine has started and back pressure meets or
exceeds 50 psi. When the engine is running, it allows flow to joysticks.
When engine shuts down, back pressure is lost and the PD assumes a
closed position.
Valve Specifications
Description
Poppet type logic valve, vent to open, side
orifice
Maximum Operating Pressure
3500 psi
Maximum Leakage
5 Drops/minute
Pilot Flow @ 1000 psi
60 Cubic Inches/Minute
Bias Pressure
50 psi
Pilot Ratio
2:1
Service Seal Kit
P33197
Valve Specifications
Description
Three-way, two-position, directional valve;
external pilot to shift
Minimum Shift Pressure
50 psi @ 1 Pilot Port
Maximum Operating Pressure
3500 psi
Nominal Flow Capacity
2 gpm
Maximum Internal Leakage
5 Cubic Inches/Minute
Service Seal Kit
P33196