Created on 12/09/2015
c
2015 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 1 of 2
MODEL
FSFA
Closed center, flow divider-combiner valve
SERIES 4 / CAPACITY: 45 - 240 L/min. / CAVITY: T-34A
Closed-center flow divider/combiners are sliding-spool, pressure-compensated devices used to split flow in one
direction and combine flow in the opposite direction. These valves may be used to accurately control two or more
cylinders or hydraulic motors where bidirectional operation is required.
TECHNICAL DATA
Maximum Operating Pressure 350 bar
Divisional Accuracy at Minimum Input Flow 50% ±4.5%
Divisional Accuracy at Max Input Flow 50% ±2.5%
Pressure Drop at Minimum Rated Input Flow 2 bar
Pressure Drop at Maximum Rated Input Flow 24 bar
Seal kit - Cartridge Buna: 990-034-007
Seal kit - Cartridge Polyurethane: 990-034-002
Seal kit - Cartridge Viton: 990-034-006
(X)CONTROL
X Not Adjustable
(A)FLOW SPLIT
A 50/50
(N)SEAL MATERIAL
N Buna-N
V Viton
MATERIAL/COATING
Standard Material/Coating
snhy.com/FSFA
TECHNICAL FEATURES
All flow divider and divider/combiner cartridges are physically interchangeable (i.e. same flow path, same cavity for a given frame size).
Operating characteristics cause the leg of the circuit with the greatest load to receive the higher percentage of flow in dividing mode. If a rigid mechanism is used to
tie actuators together, the lead actuator may pull the lagging actuator and cause it to cavitate.
In combining mode, compensating characteristics will cause the leg of the circuit with the lowest load to receive the higher percentage of flow. If a synchronization
feature is not included, an additive accuracy error will be experienced with each full stroke of the actuator.
In applications involving rigid mechanisms between multiple actuators, operating inaccuracy will cause the eventual lock-up of the system. If the mechanical
structure is not designed to allow for the operating inaccuracy inherent in the valve, damage may occur.
In motor circuits, rigid frames or mechanisms that tie motors together, and/or complete mechanical synchronized motion of the output shaft of the motors, either by
wheels to the pavement or sprockets to conveyors, will contribute to cavitation, lock-up and/or pressure intensification.
Variations in speed and lock-up can be attributed to differences in motor displacement, motor leakage, wheel diameter variance and friction of wheels on the driving
surface.
Extreme pressure intensification can occur on multiple wheel drive vehicles.
Flow between ports is limited to spool leakage. This does not provide leak proof holding capability, but can be useful in minimizing cross flow and drift.
Model Code Example: FSFAXANCONFIGURATION OPTIONS
Created on 12/09/2015
c
2015 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 2 of 2
Divisional and combining accuracy are equal.
Below the minimum flow rating there is not enough flow for the valve to modulate. It is effectively a tee. If flow starts at zero and rises, there will be no dividing or
combining control until the flow reaches the minimum rating.
Incorporates the Sun floating style construction to minimize the possibility of internal parts binding due to excessive installation torque and/or cavity/cartridge
machining variations.
PERFORMANCE CURVES
