Maeda MC815C - Counter Balance Valve (Identification Stamp T for Telescoping Cylinder)

2-57
4.14.8 COUNTER BALANCE VALVE (IDENTIFICATION STAMP “T” FOR TELESCOPING
CYLINDER)
Specifications
Max. working pressure 20.6 MPa (210 kgf/cm
2
)
Withstand pressure 30.9 MPa (315 kgf/cm
2
)
Max. flow rate 50 L/min
Rated flow rate 40 L/min
Allowable leak amount 0.05 cc/min or less (pressurizing 20.6 MPa [210 kgf/cm
2
] from B port)
Pilot pressure 1.18
+0.3
MPa [12
+3
kgf/cm²] with the valve open
Spool aperture area Equivalent to 3.2 (in spool stroke)
Check cracking pressure 0.098 MPa [1 kgf/ cm
2
]
Operating temperature range -10 - +80ºC
Troubleshooting and countermeasures
Abnormal Phenomenon Cause Remedy
During service, the telescopic
cylinder is retracted (the
boom is retracted)
･ Defect in check seat (1) or (2), or
inclusion of foreign matter
･ Damage to O-ring (1), (2), (3) or (4)
･ The pilot hole (0.3) is clogged with
foreign matter and the spool remains
in the moved state, resulting in the
check seat (2) being left open
･ Removal of foreign matter
･ Replacement of O-ring
･ Removal of foreign matter from the
pilot hole
The telescopic cylinder fails to
retract (boom does not
retract)
･ Pilot hole (0.3) is clogged with foreign
matter
･ Removal of foreign matter from the
pilot hole
65200-00800