Product Overview

The Sun Hydraulics CKEB Series is a family of pilot-to-open check valves designed for hydraulic load holding, actuator locking and controlled reverse flow.

The CKEB is a screw-in hydraulic cartridge valve using the T-2A cavity. It provides free flow from Port 2 to Port 1, while reverse flow from Port 1 to Port 2 remains blocked until sufficient pilot pressure is applied at Port 3. The pilot pressure required to open the valve is directly related to the load pressure.

The CKEB family uses a 3:1 pilot ratio, standard unsealed pilot and non-vented configuration. Sun Hydraulics identifies CKEB as a 120 L/min / 30 GPM cartridge with a 350 bar / 5,000 psi maximum operating pressure.

The models supplied in your original title are:

• CKEB-XBN
• CKEB-XCN
• CKEB-XDN
• CKEB-XEN

Their primary difference is cracking pressure:

• XBN — 1.0 bar
• XCN — 2.0 bar
• XDN — 3.5 bar
• XEN — 5.0 bar

For equipment replacement projects, the complete model code and cavity specification should be verified before installation. Our replacement solutions can be engineered for in-place interchangeability and subjected to 100% simulated working-condition testing.

Technical Specifications

CKEB-XBN

• Manufacturer: Sun Hydraulics
• Series: CKEB
• Valve Type: Pilot-to-Open Check Valve
• Model Code: CKEB-XBN
• Cavity: T-2A
• Nominal Capacity: 120 L/min / 30 GPM
• Pilot Ratio: 3:1
• Cracking Pressure: 1.0 bar
• Pilot: Standard, unsealed
• Configuration: Non-vented
• Seat: Steel seat
• Maximum Operating Pressure: 350 bar / 5,000 psi
• Maximum Valve Leakage: 0.07 cc/min at 24 cSt
• Installation Torque: 60–70 Nm
• Seal Code: N = Buna-N
• Pilot Control: External hydraulic pilot
• Flow Direction: Free Port 2 → Port 1; pilot-to-open Port 1 → Port 2

The official Sun Hydraulics ordering information identifies B = 1.0 bar cracking pressure and N = Buna-N seal.

CKEB-XCN

• Manufacturer: Sun Hydraulics
• Series: CKEB
• Valve Type: Pilot-to-Open Check Valve
• Model Code: CKEB-XCN
• Cavity: T-2A
• Nominal Capacity: 120 L/min / 30 GPM
• Pilot Ratio: 3:1
• Cracking Pressure: 2.0 bar
• Pilot: Standard, unsealed
• Configuration: Non-vented
• Seat: Steel seat
• Maximum Operating Pressure: 350 bar / 5,000 psi
• Maximum Valve Leakage: 0.07 cc/min at 24 cSt
• Installation Torque: 60–70 Nm
• Seal Material: Buna-N
• Pilot Control: External hydraulic pilot

Sun Hydraulics directly lists CKEB-XCN as the 120 L/min, T-2A, 3:1 pilot-ratio configuration with 2.0 bar cracking pressure.

CKEB-XDN

• Manufacturer: Sun Hydraulics
• Series: CKEB
• Valve Type: Pilot-to-Open Check Valve
• Model Code: CKEB-XDN
• Cavity: T-2A
• Nominal Capacity: 120 L/min / 30 GPM
• Pilot Ratio: 3:1
• Cracking Pressure: 3.5 bar
• Pilot: Standard, unsealed
• Configuration: Non-vented
• Seat: Steel seat
• Maximum Operating Pressure: 350 bar / 5,000 psi
• Maximum Valve Leakage: 0.07 cc/min at 24 cSt
• Installation Torque: 60–70 Nm
• Seal Material: Buna-N
• Pilot Control: External hydraulic pilot

Sun Hydraulics identifies D = 3.5 bar cracking pressure in the official ordering information.

CKEB-XEN

• Manufacturer: Sun Hydraulics
• Series: CKEB
• Valve Type: Pilot-to-Open Check Valve
• Model Code: CKEB-XEN
• Cavity: T-2A
• Nominal Capacity: 120 L/min / 30 GPM
• Pilot Ratio: 3:1
• Cracking Pressure: 5.0 bar
• Pilot: Standard, unsealed
• Configuration: Non-vented
• Seat: Steel seat
• Maximum Operating Pressure: 350 bar / 5,000 psi
• Maximum Valve Leakage: 0.07 cc/min at 24 cSt
• Installation Torque: 60–70 Nm
• Seal Material: Buna-N
• Pilot Control: External hydraulic pilot

The official ordering information identifies E = 5.0 bar cracking pressure. The specific CKEB-XEN product documentation also confirms T-2A cavity, 120 L/min and 350 bar ratings.

General Engineering Data

• Viscosity Range: 10–600 cSt
• Recommended Fluid Cleanliness: ISO 4406 Class 18/15 or better
• Recommended Filter Performance: β10 ≥ 75
• Buna-N Seal Temperature Range: -45 to +90 °C
• Viton Seal Temperature Range: -15 to +120 °C
• Pilot Ratio: 3:1
• Maximum Operating Pressure: 350 bar
• Maximum Leakage: 0.07 cc/min at 24 cSt

These values are published as general technical/application information for the Sun Hydraulics pilot-operated check family.

Displacement, Speed and Peak Pressure

Because CKEB is a hydraulic cartridge valve, not a pump or hydraulic motor:

• Displacement: Not applicable
• Maximum Speed: Not applicable
• Standard Maximum Operating Pressure: 350 bar / 5,000 psi

No separate model-specific peak-pressure rating is assigned here without verified manufacturer data, so a peak-pressure number is not fabricated.

Key Technical Advantages

1. 3:1 Pilot Ratio

The CKEB uses a 3:1 pilot ratio and is described by Sun Hydraulics as suitable for most general applications. The pilot piston converts the external pilot signal into the force required to release the main check element.

This architecture provides a practical balance between load-holding capability and pilot-pressure requirements.

2. 120 L/min Nominal Capacity

The CKEB provides:

120 L/min / 30 GPM nominal capacity

within the Sun Hydraulics pilot-operated check family. It occupies the 120 L/min class between the smaller CKBB/CKCB cartridges and the higher-capacity CKGB/CKIB configurations.

3. 350 Bar High-Pressure Rating

The CKEB series is rated up to:

350 bar / 5,000 psi maximum operating pressure

making it suitable for demanding industrial and mobile hydraulic circuits where actuator load locking is required.

4. Low Closed-Valve Leakage

Sun Hydraulics specifies maximum valve leakage of:

0.07 cc/min at 24 cSt

Low closed-valve leakage is particularly beneficial in load-holding circuits where unwanted actuator movement during standstill must be minimized.

5. Standard Unsealed Pilot

CKEB-XB configurations use an unsealed pilot. Sun Hydraulics explains that this arrangement allows trapped air in the pilot line to be purged from the hydraulic circuit.

Where cross-port pilot leakage must be minimized, the sealed-pilot CK*D family should be evaluated instead.

6. Multiple Cracking Pressure Options

The CKEB family provides several cracking-pressure options:

• XBN — 1.0 bar
• XCN — 2.0 bar
• XDN — 3.5 bar
• XEN — 5.0 bar

This allows engineers to select the appropriate opening characteristics for the hydraulic circuit rather than using one fixed cracking pressure across all applications.

Application Areas

Typical CKEB applications include:

• Hydraulic Cylinder Load Holding
• Vertical Lifting Systems
• Mobile Hydraulic Equipment
• Construction Machinery
• Material Handling Equipment
• Hydraulic Clamping Systems
• Industrial Machinery
• Hydraulic Presses
• Actuator Position Holding
• Hydraulic Locking Circuits
• Hydraulic Manifolds
• Compact Hydraulic Power Units

Sun Hydraulics recommends locating pilot-operated check valves as close to the actuator as practical in load-holding applications.

Expert Maintenance Tips

1. Install Close to the Actuator

For load-holding applications, position the pilot-operated check valve as close to the actuator as practical.

Reducing the volume of hydraulic fluid between the valve and actuator helps limit:

• Actuator movement
• Pressure-response delay
• Hydraulic compliance
• Dynamic stopping effects

2. Verify the T-2A Cavity

The CKEB cartridge is specifically designed for:

T-2A cavity

Before replacement, verify the manifold cavity rather than identifying the cartridge solely by the CKEB family name.

3. Match Cracking Pressure Exactly

Do not treat all CKEB models as equivalent.

The models supplied correspond to:

XBN = 1.0 bar
XCN = 2.0 bar
XDN = 3.5 bar
XEN = 5.0 bar

Changing cracking pressure can alter the forward-flow pressure differential and overall circuit response.

4. Apply 60–70 Nm Installation Torque

Sun Hydraulics specifies:

60–70 Nm installation torque

Use a calibrated torque wrench during cartridge installation to avoid damaging the cartridge or cavity interface.

5. Maintain Hydraulic Cleanliness

Sun Hydraulics recommends:

ISO 4406 Class 18/15 or better

and recommends β10 ≥ 75 filtration performance for achieving this cleanliness level in most systems.