Created on 07/01/2015
c
2015 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 1 of 2
MODEL
CWIA
3:1 pilot ratio, vented counterbalance valve
SERIES 4 / CAPACITY: 480 L/min. / CAVITY: T-24A
4-Port Vented
4-Port Vented, Non-adjustable
Vented counterbalance valves with pilot assist are meant to control an overrunning load. The check valve allows
free flow from the directional valve (port 2) to the load (port 1) while a direct-acting, pilot-assisted relief valve
controls flow from port 1 to port 2. Pilot assist at port 3 lowers the effective setting of the relief valve at a rate
determined by the pilot ratio. Backpressure at port 2 does not affect the valve setting because the spring chamber
references the vent (port 4).
Other names for this valve include motion control valve and over center valve.
TECHNICAL DATA
Pilot Ratio 3:1
Maximum Recommended Load Pressure at Maximum Setting 215 bar
Maximum Setting 280 bar
Factory Pressure Settings Established at 30 cc/min.
Maximum Valve Leakage at Reseat 0,3 cc/min.
Check Cracking Pressure 1,5 bar
Adjustment - Number of Counterclockwise Turns to Increase Setting 5
Reseat >85% of setting
Locknut Hex Size 15 mm
Locknut Torque 9 - 10 Nm
Seal kit - Cartridge Buna: 990-024-007
Seal kit - Cartridge Polyurethane: 990-024-002
Seal kit - Cartridge Viton: 990-024-006
(L)CONTROL
L Standard Screw Adjustment
C Tamper Resistant - Factory Set
(H)FUNCTIONAL SETTING RANGE
H 1000 - 4000 psi (70 - 280 bar), 3000 psi
(210 bar) Standard Setting
I 400 - 1500 psi (28 - 105 bar), 1000 psi
(70 bar) Standard Setting
(N)SEAL MATERIAL
N Buna-N
V Viton
MATERIAL/COATING
Standard Material/Coating
/AP Stainless Steel, Passivated
/LH Mild Steel, Zinc-Nickel
snhy.com/
CWIA
TECHNICAL FEATURES
Counterbalance valves should be set at least 1.3 times the maximum load induced pressure.
Turn adjustment clockwise to decrease setting and release load.
Full clockwise setting is 200 psi (14 bar).
Model Code Example: CWIALHNCONFIGURATION OPTIONS
Created on 07/01/2015
c
2015 Sun Hydraulics Corporation See www.sunhydraulics.com for detailed product information 2 of 2
All 4-port counterbalance, load control, and pilot-to-open check cartridges are physically interchangeable (i.e. same flow path, same cavity for a given frame size).
Reseat exceeds 85% of set pressure when the valve is standard set. Settings lower than the standard set pressure may result in lower reseat percentages.
Pressure at port 4 is added to the effective relief setting at a rate of 1 plus the pilot ratio times the pressure.
Sun counterbalance cartridges can be installed directly into a cavity machined in an actuator housing for added protection and improved stiffness in the circuit.
This valve has positive seals between all ports.
With vented valves, a lower pilot ratio may be required to achieve machine stability compared to non-vented valves.
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
