Product Overview
The KSO-G02-2BB-30-EN, KSO-G02-4CA-30-EN, KSO-G03-2DP-20-EN, and KSO-G03-4CA-20 are core models in the DAIKIN KSO series of solenoid pilot-operated directional control valves, covering G02 (1/4 inch) and G03 (3/8 inch) nominal sizes. The KSO series delivers an exceptional combination of 35 MPa (350 kgf/cm²) high pressure and 100 L/min (G02) / 160 L/min (G03) high flow capacity. Constructed from high-strength cast iron, the valve body delivers superior rigidity and fatigue resistance. The product is designed to IEC Pub529 IP65 dust and water-proof standards and complies with European CE safety regulations.
Model Overview:
KSO-G02-2BB-30-EN: G02 size (1/4 inch), 2-way, 2-position solenoid directional valve featuring spring offset configuration with SOL.b solenoid. Operates on AC200V (50/60Hz) supply, single solenoid operation—when de-energized, the spool returns by spring force.
KSO-G02-4CA-30-EN: G02 size (1/4 inch), 4-way, 3-position solenoid directional valve featuring spring centered configuration. Operates on AC100V (50/60Hz) supply, double solenoid operation—when de-energized, the spool automatically returns to neutral by spring force.
KSO-G03-2DP-20-EN: G03 size (3/8 inch), 4-way, 3-position solenoid directional valve. Operates on DC24V supply, with DIN 43650 / ISO 4400 standard connector, double solenoid operation.
KSO-G03-4CA-20: G03 size (3/8 inch), 4-way, 3-position solenoid directional valvefeaturing spring centered configuration. Operates on AC100V supply, double solenoid operation. Compatible with modular stack valves in 02 and 03 series.
As original DAIKIN KSO series solenoid valves, these products offer complete interchangeability within the same series and size, requiring no modifications to mounting interfaces or piping layouts.
Technical Specifications
KSO-G02 Series Common Specifications
Brand: DAIKIN
Series: KSO Series
Nominal Size: G02 (1/4 inch)
Mounting Standard: ISO 4401 / CETOP 3 / NG6
Mounting Type: Gasket Mount
Maximum Operating Pressure: 35 MPa (350 kgf/cm²)
Maximum Flow Rate: 100 L/min
Allowable Back Pressure: 17.5 MPa (175 kgf/cm²)
Maximum Shifting Frequency: 240 cycles/min
Protection Class: IEC Pub529 IP65
Insulation Class: Class B (Coil: Class H)
Dielectric Strength: AC1500V for 1 minute
Insulation Resistance: 50 MΩ minimum
Compatible Fluids: Petroleum-based hydraulic oil
Duty Rating: Continuous
KSO-G03 Series Common Specifications
Brand: DAIKIN
Series: KSO Series
Nominal Size: G03 (3/8 inch)
Mounting Standard: ISO 4401 / CETOP 5 / NG10
Mounting Type: Gasket Mount
Maximum Operating Pressure: 35 MPa (350 kgf/cm²)
Maximum Flow Rate: 160 L/min (DC) / 130 L/min (AC)
Allowable Back Pressure: 16 MPa (160 kgf/cm²)
Maximum Shifting Frequency: 240 cycles/min
Protection Class: IEC Pub529 IP65
Insulation Class: Class B (Coil: Class H)
Dielectric Strength: AC1500V for 1 minute
Insulation Resistance: 50 MΩ minimum
Compatible Fluids: Petroleum-based hydraulic oil
Certifications: CE certified
Model-Specific Specifications
KSO-G02-2BB-30-EN:
Model: KSO-G02-2BB-30-EN
Spool Configuration: 2-way, 2-position
Spring Arrangement: Spring Offset (with SOL.b solenoid)
Voltage: AC200V (50/60Hz)
Starting Current: 50Hz 1.21A / 60Hz 1.07A
Holding Current: 50Hz 0.26A / 60Hz 0.19A
Holding Power: 50Hz 21.5W / 60Hz 18W
Permissible Voltage Fluctuation: 50Hz 80–110% / 60Hz 90–121%
Wiring: Terminal Box Type
Indicator Lamp: Equipped
Surge Killer: Equipped
Operating Time: Energized 0.01–0.025s / Spring Return 0.01–0.045s
Weight: 1.5 kg
KSO-G02-4CA-30-EN:
Model: KSO-G02-4CA-30-EN
Spool Configuration: 4-way, 3-position
Spring Arrangement: Spring Centered
Neutral Position: A & B ports open to T
Voltage: AC100V / 100-110V (50/60Hz)
Wiring: Terminal Box Type
Indicator Lamp: Equipped
Weight: Approx. 1.5–1.8 kg
KSO-G03-2DP-20-EN:
Model: KSO-G03-2DP-20-EN
Spool Configuration: 4-way, 3-position
Spring Arrangement: Double Solenoid
Voltage: DC24V
Power Consumption: 38 W
Electrical Connection: DIN 43650 / ISO 4400
Weight: Approx. 4.4 kg
KSO-G03-4CA-20:
Key Technical Advantages
1. High-Pressure High-Flow Performance
The KSO series delivers an exceptional combination of 35 MPa operating pressure and 100 L/min (G02) and 160 L/min (G03) flow capacity. This performance places it at the forefront of solenoid directional valves in its class, making it suitable for demanding high-pressure, high-flow hydraulic systems.
2. Rugged Environmental Protection
Designed to IEC Pub529 IP65 dust and water-proof standards, the valve features effective protection against dust ingress and water jets from any direction. CE compliance makes it suitable for export to European markets and equipment requiring CE certification.
3. High-Reliability Solenoid System
The solenoid coil utilizes Class H insulation material for excellent heat resistance. AC-powered models feature wide voltage tolerance ranges. Insulation resistance exceeds 50 MΩ with dielectric strength of AC1500V for 1 minute. The solenoid supports continuous duty rating.
4. Precision Machining and Long Service Life
The valve body is manufactured from high-strength cast iron, with spool and bore surfaces precision-ground to ensure minimal internal leakage and long-term shifting accuracy. With a maximum shifting frequency of 240 cycles/min, the valve is ideal for high-cycle applications.
5. Flexible Spool Functions and Electrical Options
The KSO series offers a wide range of spool configurations—2-way 2-position (2BB), 4-way 3-position spring centered (4CA/4CA-20/2DP-20-EN), and more. Supports multiple voltage options including AC100V, AC200V, and DC24V. EN suffix models feature built-in surge killers.
6. Modular Stack Valve Compatibility
The KSO-G02 and KSO-G03 series support modular stack valve configurations. Allows flexible integration of throttle valves, check valves, pressure reducing valves, and other hydraulic components—significantly simplifying hydraulic system layout and reducing leakage risk.
Application Areas
KSO-G02-2BB-30-EN (2-way, 2-position, spring offset, G02):
Unloading Circuits — System unloading and pressure release control
Cooling and Filtration Circuits — On/off control for auxiliary oil circuits
Safety Interlock Devices — Emergency shutdown and safety valve control
KSO-G02-4CA-30-EN (4-way, 3-position, spring centered, G02):
CNC Machine Tools — Directional control for machine tool hydraulic systems
Injection Molding Machinery — Directional control for auxiliary functions
General Industrial Hydraulic Systems — Standard 4-way, 3-position directional control
KSO-G03-2DP-20-EN / KSO-G03-4CA-20 (4-way, 3-position, spring centered, G03):
Injection Molding Machinery — High-flow directional control for clamping, injection, and ejection cylinders
Hydraulic Presses and Forging Equipment — High-flow directional control for presses and forming equipment
Die-Casting Machines — High-flow directional control for high-pressure casting equipment
Construction Machinery — High-flow hydraulic directional control for excavators, loaders, and mobile equipment
Steel and Mining Equipment — High-flow directional control for rolling mills and heavy-duty systems
Expert Maintenance Tips
1. Installation Guidelines
G02 size mounting surface must conform to ISO 4401 / CETOP 3 / NG6 standards. Use M5 mounting bolts.
G03 size mounting surface must conform to ISO 4401 / CETOP 5 / NG10 standards. Use M6 mounting bolts (M8 optional).
Thoroughly clean the mounting surface and all ports (P, A, B, T) before installation to prevent foreign particles from entering and causing spool sticking or seal damage.
KSO series supports modular stack valve configurations—pay attention to sealing and bolt length between stacked valve layers.
2. Hydraulic Fluid Cleanliness
Recommended fluid: Petroleum-based hydraulic oil.
Note: Certain spool types (5C/66C/51C) have maximum operating pressure of 25 MPa (250 kgf/cm²), not 35 MPa. Confirm pressure rating with the complete model code.
Install a return line filter with minimum 25 μm filtration rating upstream of the valve.
3. Electrical Connection Specifications
KSO-G02-2BB-30-EN uses AC200V supply, with permissible voltage fluctuation: 50Hz 80–110% / 60Hz 90–121%.
KSO-G02-4CA-30-EN uses AC100V supply.
KSO-G03-2DP-20-EN uses DC24V supply, with DIN 43650 / ISO 4400 connector.
KSO-G03-4CA-20 uses AC100V supply.
KSO-G02-2BB-30-EN features built-in surge killer—no additional surge suppressor required.
4. Back Pressure Control
G02 size system return line back pressure must not exceed 17.5 MPa (175 kgf/cm²) .
G03 size must not exceed 16 MPa (160 kgf/cm²) .
If back pressure is excessive, consider using a dedicated return line or routing the valve return port directly to the tank.
5. Periodic Maintenance Inspection
Inspect the valve body for external oil leakage every 2,000 operating hours or at least annually.
Check electrical connectors/terminal boxes for looseness, oxidation, or moisture ingress.
If response lag or unstable shifting is observed, first check system fluid cleanliness and verify the spool is not sticking.
Indicator lamps (on terminal box models with indicators) help quickly verify solenoid energization status.
