FLUID POWER SYMBOL
TUCSON
Where measurements are critical request certified drawings. We reserve the right to change specifications without notice.
4
Umbergaon, Gujarat
C1B 246/5, G.I.D.C. Indl. Estate
tucson@vsnl.com
3D ISOMETRIC VIEW
OVERCENTRE VALVEOSI35
Specifications
Figures based on: Oil Temp = 40°C Viscosity = 40 cSt
Rated Flow 40 lpm
Max Setting
Load Induced Pressure : 270 bar
Relief Setting : 350 bar
Cartridge Material
Working parts : Hardened, ground steel
External surfaces : Zinc plated
Weight (Cartridge only)
OSI35: 0.150 kg
Cavity Number TH6610 (Refer Cavities Section)
Manifold Material
Aluminium (upto 250 bar)
Add Suffix ‘729’ for SG Iron (350 bar)
Torque into Cavity 45 Nm
Mounting Line/Subplate
Seal Kit Number SKOSI35 (Nitrile) SKOSI35 V (Viton
®
)
Filtration Level BS5540/4 Class 18/13 (25µ nominal)
Operating Temp -20°C to +90°C (Standard Seals)
Leakage Less than 0.3 millilitres/min (5 dpm)
Viscosity Range 5 to 500 cSt
Application
Overcentre valves give static and
dynamic control of loads by regulating
flow into and out of hydraulic actuators.
The Overcentre valve will stop the load
from running away in the event of a
hose burst. If open center directional
control valves are used, they will allow
the thermal expansion relief of the
hydraulic fluid. These valves provide
excellent hose burst protection.
Operation
The check section allows free flow into
the actuator (from 2 to 1) then holds and
locks the load against movement (from
1 to 2). The pilot pressure in the pilot port
(3) will give a controlled movement to
piston when the pressure is applied. The
pressure required to open the valve and
allow movement depends on the pilot
ratio of the valve. The pressure required
t
o open the valve and start actuator
movement can be calculated as follows:
Pilot Ratio
7:1
Best suited for applications where
the load varies and machine
structure can induce instability.
Other ratios can be made available
upon request.
Pilot = Relief Setting - Load Pressure
Pressure Pilot Ratio
1
2 3
HEX ADJUST
5 A/F
25.4 A/F
17 A/F
M20 x 1.5
1
2
3
43
3
1
2
4-210.A
52