Komatsu PC200-8M0 Shop Manual page 170

SEN06120-00
Boom regeneration circuit
When cylinder head pressure is lower than bottom pressure (hydraulic drift, etc.)
1. Main pump
2. Boom valve spool
3. Pressure compensation valve
4. Suction safety valve
5. Suction valve
6. Check valve
7. LS shuttle valve
Function
q The regeneration circuit is installed across the cylinder bottom and cylinder head to increase flow to the
cylinder head when the boom is lowered.
Operation
q When the cylinder head pressure is lower than the bottom pressure, some of pressurized oil (A) from
the cylinder bottom flows to drain circuit (B) from the notch of boom spool (2).
The remaining oil flows to regeneration circuit (C), opens check valve (6) and flows to the cylinder bot-
q
tom through circuit (D).
q Flow from regeneration circuit (C) merges into the oil from pump (1) in circuit (E).
28
10-402
402 Hydraulic system, Part 2
Functions and operation by valve
PC200, 200LC, 220, 220LC-8M0