Boom Cylinder Holding Valve Outline; Boom Cylinder Holding Valve Specifications; Boom Cylinder Holding Valve Circuit Diagram - Kubota KX080-3 Workshop Manual

WSM KX080-3 Mechanism
I. Boom cylinder holding valve
a. Outline
The holding valve has been developed for hydraulic shovels. This control valve prevents the cylinder against
gravity fall in the non-operating status and against sudden fall in case of hose burst.
H
(1) (2) (3)
b. Specifications
Maximum operating pressure
Maximum allowable flow rate (P-port) A
Cracking pressure B-port pressurized
A-port pressurized
PL-port pressurized
Leakage Holding valve internal
Hydraulic oil used
Allowable hydraulic oil contamination
Operating temperature range
c. Circuit diagram
- 0 - 3. 0 / 3 0
(4) (5) (6) (7)
31.4 MPa, 320 kgf/cm
B 150 L/min, 39.63 GPM
PB = 30.4
PA = 0.2 MPa, 2 kgf/cm
PPL= 0.5
0.8 cc/min at B port, 8.3MPa (85 kgf/cm
Mineral hydraulic oil ISO VG3 or VG46 or equivalent
Below Class NAS10
-20
IV-M-112
(1) Holding valve
(2) Nominal diameter (size)
(3) B-port configuration (G: Threaded port)
(4) Rotation number
(5) Circuit code
(6) Major revision code
(7) Relief set pressure
2
4551 psi
0.5 MPa, 310 5 kgf/cm
2
28 psi
+0.05 +0.5
MPa, 5 kgf/cm
- 0.10 - 1.0
+95°C
IV Hydraulic System
2
, 4409 71 psi
2
+7.0
71 psi
- 14.2
2
)