KSO-G03-4CB-20 | DAIKIN Solenoid Valve 35MPa 160L/min NG10

Product Overview

The KSO-G03-4CB-20, JSO-G03-4CB-20, and JSO-G03-4CD-20 are core models in the DAIKIN KSO/JSO series of solenoid operated directional control valves, G03 size (3/8 inch), with mounting pattern conforming to ISO 4401 / CETOP 5 / NG10 standards. The series delivers an exceptional combination of 35 MPa (350 kgf/cm²) high pressure and 160 L/min high flow. Constructed from high-strength cast iron, the valve body delivers superior rigidity and fatigue resistance.

JSO Series (Pilot Solenoid Valve) is a solenoid pilot operated directional control valve developed on the basis of the KSO series. The pilot stage employs the highly reliable KSO-G02, ensuring long service life and reliable operation. Suitable for integration into equipment compliant with European safety standards (CE). KSO and JSO series share identical mounting dimensions and performance specifications, offering complete interchangeability.

Model Code Breakdown:

• KSO / JSO – Solenoid Operated Valve / Pilot Solenoid Valve

• G03 – G03 Size (3/8 inch, NG10 / CETOP 5)

• 4CB / 4CD – 4-way Spool Type (CB/CD differ in center position function)

• 20 – Design Series (20 Series)

Technical Specifications 

KSO-G03 / JSO-G03 Series Common Specifications:

• Brand: DAIKIN

• Series: KSO Series / JSO Series

• Product Type: Solenoid Operated Directional Valve / Pilot Solenoid Valve

• 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)

• Note: Certain spool types (5C/66C/51C) have max. operating pressure of 25 MPa (250 kgf/cm²)

• Maximum Flow: 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

• European Safety Standard: CE compliant

• Mounting Bolts: M6×35 (4 bolts)

• Tightening Torque: 12–15 N·m

KSO-G03-4CB-20 Specifications:

• Model: KSO-G03-4CB-20

• Spool Configuration: 4-way, 3-position

• Spring Arrangement: Spring Centered

• Spool Type: 4CB

• Design Series: 20 Series

• Wiring: Terminal Box / DIN Connector

• Weight: Approx. 4.4 kg

JSO-G03-4CB-20 Specifications:

• Model: JSO-G03-4CB-20

• Product Type: Pilot Solenoid Valve

• Spool Configuration: 4-way, 3-position

• Spring Arrangement: Spring Centered

• Spool Type: 4CB

• Pilot Valve: KSO-G02 Series

• Design Series: 20 Series

• Weight: Approx. 4.4 kg

JSO-G03-4CD-20 Specifications:

• Model: JSO-G03-4CD-20

• Product Type: Pilot Solenoid Valve

• Spool Configuration: 4-way, 3-position

• Spring Arrangement: Spring Centered

• Spool Type: 4CD

• Pilot Valve: KSO-G02 Series

• Design Series: 20 Series

• Weight: Approx. 4.4 kg

Key Technical Advantages

1. High-Pressure High-Flow Performance

The KSO/JSO-G03 series delivers an exceptional combination of 35 MPa operating pressure and 160 L/min flow capacity. This performance places it at the forefront of NG10 size solenoid directional valves, 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 ideal for export to European markets and equipment requiring CE certification.

3. JSO Series Pilot Design — Long Life and Reliable Operation

The JSO series features solenoid pilot operated design, with the pilot stage employing the highly reliable KSO-G02. The separation of pilot and main stages allows the solenoid to actuate a small pilot spool, which in turn controls the main stage for large flow directional switching—significantly reducing solenoid power consumption while ensuring long service life and reliable operation.

4. High-Reliability Solenoid System

The solenoid coil utilizes Class H insulation material for excellent heat resistance. The solenoid supports continuous duty rating, ensuring long-term stable operation. Insulation resistance exceeds 50 MΩ with dielectric strength of AC1500V for 1 minute.

5. 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.

6. Flexible Spool Functions and Modular Stack Compatibility

The KSO/JSO series offers multiple spool configurations including 4CB and 4CD to suit different center position requirements. G02/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

• Injection Molding Machinery — Directional control for clamping, injection, and ejection cylinders

• Hydraulic Presses and Forging Equipment — Directional control for presses and forming equipment

• CNC Machine Tools — Directional control for machine tool hydraulic systems

• Die-Casting Machines — Directional control for high-pressure casting equipment

• Construction Machinery — High-flow hydraulic directional control for excavators, loaders, and mobile equipment

• Industrial Automation Production Lines — Hydraulic actuator control for automated production lines

• Steel and Mining Equipment — Directional control for rolling mills and heavy-duty hydraulic systems

• Marine and Port Machinery — High-flow control for winches and cranes

Expert Maintenance Tips

1. Installation Guidelines

• G03 size mounting surface must conform to ISO 4401 / CETOP 5 / NG10 standards.

• Use 4 M6×35 mounting bolts 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 the valve and causing spool sticking or seal damage.

• KSO and JSO series share identical mounting dimensions for direct interchangeability.

2. Hydraulic Fluid Cleanliness

• Recommended fluid: Petroleum-based hydraulic oil. For other fluid types, verify seal material compatibility.

• 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-G03-4CB-20 voltage varies by configuration (AC200V / DC24V, etc.). Verify nameplate voltage matches supply voltage before connection.

• JSO-G03-4CD-20 supports AC 220V (50Hz) / AC 240V (60Hz).

• Connector standard: DIN 43650 / ISO 4400. Ensure the connector is fully locked to achieve IP65 protection.

4. Back Pressure Control

• G03 size system return line back pressure 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.