Komatsu PC20R-8 Shop Manual page 73

3. Functions and operation of each valve
NAMES OF HYDRAULIC CIRCUITS AND VALVES
P2
P
A9
P
A8
P
A7
P
A6
P
A1
1
P1
S
6
PC20R-8 PC27R-8
8
4
3
4
4
3
4
3
4
4
3
3
3
3
3
5
2
7
C T
P2
T
B9
To hammer
A9
P
B9
B8
A8
Bucket
P
B8
B7
A7
Boom
P
B7
B6
A6
Arm
P
B6
B5
A5
Blade
B4
Boom
A4
swing
Reverse
P1
B3
R.H. travel
A3
P2
Forwards
Reverse
P1
B2
L.H. travel
A2
P2
Forwards
Left
B
B1
Swing
motor
A1
A
P
B1 Right
LS
RKP04481
1. Unload valve LS+16 bar
2
(16 kg/cm )
2. Safety valve: 206
2
(210 kg/cm )
3. Pressure compensation
valve
4. Suction valve
5. Main relief valve:
2
235 bar (240 kg/cm )
6. Back pressure check valve
(cracking pressure):
2
0.45 bar (4.5 kg/cm )
7. Cooler by-pass valve
(cracking pressure):
2
0.4 bar (4 kg/cm )
8. Pilot relief valve:
2
29 bar (30 kg/cm )
10-55
bar