Flow Control (& Check) / Pilot Operated Flow Control (& Check) Valves0 pages

Pub. EC-0301

FLOW CONTROL (AND CHECK) VALVES
FG
FCG -01/02/03/06/10 (1/8,1/4,3/8,3/4,1-1/4)
PILOT OPERATED
FLOW CONTROL (AND CHECK) VALVES
FHG
FHCG -02/03/06/10 (1/4,3/8,3/4,1-1/4)
Sub-plate Mounting

FLOW
CONTROLS

Up to 21 MPa (3050 PSI), 500 L/min (132 U.S.GPM)
Flow Control and Check Valves ...... Page 2
These valves are pressure and temperature compensating type valves and maintain a constant flow rate
independent of change in system pressure (load) and
temperature (viscosity of the fluid). They control flow
rate of the hydraulic circuit and eventually control
speed of the actuator precisely.
Valves with an integral check valve allow a controlled
flow and reverse free flow. Repeated resetting can be
made easily with a digital readout.

Pilot Operated Flow Control
and Check Valves ......................... Page 14
Flow control of these valves is continuously made by
a hydraulically operated pilot piston mechanism
which controls opening area of the orifice of
the valve. With the use of these valves, shockless
operation either in acceleration or deceleration can be
obtained. With the compensator for the pressure and
temperature, stable flow control can be obtained
regardless of the changes in the pressure (load) and
temperature (oil viscosity).

T

T

P

P

FG
O M

O M

FCG

Hydraulic Fluids

B

A

FHG

A

B

FHCG

Fluid Types
Any type of hydraulic fluids listed in the table below can be used.
Petroleum base oils
Synthetic fluids
Water containing fluids

Use fluids equivalent to ISO VG 32 or VG 46.
Use phosphate ester or polyol ester fluid. When phosphate ester fluid is used, prefix "F-" to the
model number because the special seals (fluororubber) are required to be used.
Use water-glycol fluid.

Note: For use with hydraulic fluids other than those listed above, please consult your Yuken representatives in advance.

Recommended Viscosity and Oil Temperatures
Viscosity ranging between 15 - 400 mm2/s (77 - 1800 SSU).
Oil temperatures between -15/+70°C (5 - 158°F).
Use hydraulic fluids which satisfy the recommended viscosity and oil temperatures given above.
Control of Contamination
Due caution must be paid to maintaining control over contamination of the hydraulic fluids which may otherwise
lead to breakdowns and shorten the life of the valves. Please maintain the degree of contamination within NAS 1638Grade 12. Use 25 μ m or finer line filter.

No.1

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