Product Overview
The KSO-G02-2BP-30-FN, KSO-G03-2CP-20, KSO-G03-2AP-20-H2, and KSO-G03-2BP-20 are core models in the DAIKIN KSO series of solenoid pilot-operated directional control valves. The KSO series delivers an exceptional combination of 35 MPa (350 kgf/cm²) high pressure and 100 L/min (G02 size) / 160 L/min (G03 size) 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.
The KSO-G02 and KSO-G03 series support modular stack valve configurations, enabling flexible integration with 02 and 03 series modular stack valves.
Spool Configuration by Model:
KSO-G02-2BP-30-FN: G02 size (1/4 inch), 4-way, 2-position solenoid directional valve featuring spring offset configuration (with SOL.b solenoid), single solenoid operation. The FN suffix denotes a factory internal configuration code.
KSO-G03-2CP-20: G03 size (3/8 inch), 4-way, 3-position solenoid directional valve featuring spring centered configuration. All ports fully closed in neutral (closed center), double solenoid operation. Ideal for applications requiring precise actuator positioning and locking in neutral.
KSO-G03-2AP-20-H2: G03 size (3/8 inch), 4-way, 2-position solenoid directional valve. The H2 suffix denotes a factory internal configuration code.
KSO-G03-2BP-20: G03 size (3/8 inch), 4-way, 2-position solenoid directional valve featuring spring return configuration, single solenoid operation. When de-energized, the spool returns to the initial position by spring force.
Technical Specifications
KSO-G02-2BP-30-FN Specifications:
Model: KSO-G02-2BP-30-FN
Brand: DAIKIN
Series: KSO Series
Nominal Size: G02 (1/4 inch)
Mounting Standard: ISO 4401-03 / 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 F)
Dielectric Strength: AC1500V for 1 minute
Insulation Resistance: 50 MΩ minimum
Coil Voltage: DC24V
Holding Current: 1.22 A
Holding Power: 29.2 W
Permissible Voltage Fluctuation: 90–110%
Wiring: Terminal Box Type
Indicator Lamp: Equipped
Surge Killer: Not equipped
Spring Arrangement: Spring Offset (with SOL.b)
Solenoid Configuration: Single Solenoid
Compatible Fluids: Petroleum-based hydraulic oil
Mounting Bolts: M5
Weight: 1.7 kg
KSO-G03-2CP-20 Specifications:
Model: KSO-G03-2CP-20
Brand: DAIKIN
Series: KSO Series
Nominal Size: G03 (3/8 inch)
Mounting Standard: ISO 4401-05 / CETOP 5 / NG10
Mounting Type: Gasket Mount
Maximum Operating Pressure: 35 MPa (350 kgf/cm²)
Maximum Flow Rate: 160 L/min
Allowable Back Pressure: 16 MPa (160 kgf/cm²)
Maximum Shifting Frequency: 240 cycles/min
Protection Class: IEC Pub529 IP65
Coil Voltage: DC24V
Holding Current: 1.6 A
Holding Power: 38 W
Permissible Voltage Fluctuation: 90–110%
Wiring: Terminal Box Type
Indicator Lamp: Equipped
Spool Configuration: 4-way, 3-position
Spring Arrangement: Spring Centered
Center Position: All ports closed
Solenoid Configuration: Double Solenoid
Compatible Fluids: Petroleum-based hydraulic oil
Mounting Bolts: M6×35
Tightening Torque: 12–15 N·m
Weight: 5.8 kg
KSO-G03-2AP-20-H2 Specifications:
Model: KSO-G03-2AP-20-H2
Brand: DAIKIN
Series: KSO Series
Nominal Size: G03 (3/8 inch)
Mounting Standard: ISO 4401-05 / CETOP 5 / NG10
Maximum Operating Pressure: 35 MPa (350 kgf/cm²)
Maximum Flow Rate: 160 L/min
Allowable Back Pressure: 16 MPa (160 kgf/cm²)
Maximum Shifting Frequency: 240 cycles/min
Spool Configuration: 4-way, 2-position
Coil Voltage: DC24V
Wiring: Terminal Box Type
Temperature Range: 30–90°C
Nominal Pressure: 32 MPa
Body Material: Cast Iron
Weight: Approx. 4.0–5.5 kg
KSO-G03-2BP-20 Specifications:
Model: KSO-G03-2BP-20
Brand: DAIKIN
Series: KSO Series
Nominal Size: G03 (3/8 inch)
Mounting Standard: ISO 4401-05 / 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
Coil Voltage: DC24V
Wiring: Terminal Box Type
Spool Configuration: 4-way, 2-position
Spring Arrangement: Spring Return
Solenoid Configuration: Single Solenoid
Compatible Fluids: Petroleum-based hydraulic oil
Mounting Bolts: G03: M6 (M8 optional)
Weight: 4.4 kg
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 F insulation material for excellent heat resistance. Under DC24V supply, holding current is 1.22 A (G02) / 1.6 A (G03) with holding power of 29.2 W (G02) / 38 W (G03). The valve accommodates 90–110% voltage fluctuation. Insulation resistance exceeds 50 MΩ with dielectric strength of AC1500V for 1 minute. The solenoid supports continuous duty rating, ensuring long-term stable operation.
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—4-way 2-position (2BP/2AP), 4-way 3-position spring centered closed center (2CP), and more. Supports DC24V and other voltage options. The extensive configuration options flexibly accommodate different control systems and application requirements.
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. G02 size uses M5 mounting bolts; G03 size uses M6 (M8 optional).
Application Areas
KSO-G02-2BP-30-FN (4-way, 2-position, spring offset, G02 size):
Unloading Circuits — System unloading and pressure release control
Hydraulic Cylinder Rapid Traverse — Oil circuit switching for differential circuits
Cooling and Filtration Circuits — On/off control for auxiliary oil circuits
Safety Interlock Devices — Emergency shutdown and safety valve control
KSO-G03-2CP-20 (4-way, 3-position, spring centered, closed center, G03 size):
Injection Molding Machinery — Directional and positioning control for clamping, injection, and ejection cylinders
CNC Machine Tools — Precision worktable positioning and locking control
Hydraulic Presses and Forging Equipment — Press slide position holding and control
Die-Casting Machines — Directional and positioning control for high-pressure casting equipment
Industrial Automation Production Lines — Hydraulic actuator control requiring precision position holding
KSO-G03-2AP-20-H2 / KSO-G03-2BP-20 (4-way, 2-position, spring offset/return, G03 size):
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
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 4401-03 / CETOP 3 / NG6 standards. Use M5 mounting bolts.
G03 size mounting surface must conform to ISO 4401-05 / CETOP 5 / NG10 standards. Use M6×35 mounting bolts (M8 optional) with recommended tightening torque of 12–15 N·m.
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-G02 and KSO-G03 series support 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
All four models use DC24V supply.
Permissible voltage fluctuation range: 90–110%. Voltage fluctuation beyond this range may affect normal valve shifting or shorten coil life.
KSO series features terminal box wiring with indicator lamps. Pay attention to indicator light connections during wiring.
Ensure the terminal box cover is properly sealed to maintain IP65 protection.
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 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 help quickly verify solenoid energization status.
