FDCB-LAN CBEH-LKN CBEH-LDN CWIA-LHN Sun Hydraulic Cartridge Valve 350 bar

Product Overview

This SUN series screw-in cartridge valve portfolio covers four core models: FDCB-LAN, CBEH-LKN, CBEH-LDN, and CWIA-LHN. These products span two major functional categories — flow control and load holding (counterbalance) — delivering comprehensive cartridge valve solutions for hydraulic systems.

• FDCB-LAN: Fully adjustable, pressure-compensated flow control valve with reverse-flow check, providing precise flow regulation for meter-in or meter-out applications with wide pressure fluctuations.

• CBEH-LKN: 10:1 pilot ratio, standard capacity counterbalance valve (non-vented) for smooth control of overrunning loads and load-holding.

• CBEH-LDN: Same-series 10:1 pilot ratio counterbalance valve with configuration variations in setting range and seal options.

• CWIA-LHN: 3:1 pilot ratio, vented counterbalance valve with 480 L/min capacity for high-flow overrunning load control applications.

All models feature screw-in cartridge construction for direct installation into standardized SUN cavities, offering convenient assembly and low maintenance costs.

As a high-performance alternative to genuine Sun Hydraulics series products, this portfolio delivers full performance parity with Sun original specifications, featuring 100% form-fit-function interchangeability — cavity dimensions, installation torque specifications, and performance parameters are identical to the original, enabling direct replacement without manifold modifications. Every unit undergoes 100% simulated in-service testing prior to shipment, ensuring proven reliability under real-world operating conditions.

Technical Specifications 

FDCB-LAN — Fully Adjustable, Pressure-Compensated Flow Control Valve

• Product Type: Fully adjustable, pressure-compensated flow control valve with reverse-flow check

• Cavity: T-5A

• Series: 2

• Capacity: 12 gpm (45 L/min)

• Maximum Operating Pressure: 5000 psi (350 bar)

• Adjustment: 5 CCW turns from fully closed to fully open

• Minimum Leakage at Shut-Off: 0.2 gpm (0.8 L/min)

• Valve Hex Size: 1 1/8 in (28.6 mm)

• Valve Installation Torque: 45 – 50 lbf·ft (61 – 68 N·m)

• Adjustment Screw Internal Hex Size: 5/32 in (4 mm)

• Locknut Hex Size: 9/16 in (15 mm)

• Locknut Torque: 80 – 90 lbf·in (9 – 10 N·m)

• Weight: 0.61 lb (0.28 kg)

• Seal Kits: Buna (990203007) / EPDM (990203014) / Viton (990203006)

CBEH-LKN — 10:1 Pilot Ratio, Standard Capacity Counterbalance Valve

• Product Type: 10:1 pilot ratio, standard capacity counterbalance valve (3-port non-vented)

• Cavity: T-2A

• Series: 2

• Capacity: 30 gpm (120 L/min)

• Maximum Operating Pressure: 5000 psi (350 bar)

• Pilot Ratio: 10:1

• Maximum Recommended Load Pressure at Maximum Setting: 3850 psi (270 bar)

• Maximum Setting: 5000 psi (350 bar)

• Check Cracking Pressure: 25 psi (1.7 bar)

• Reseat: >85% of setting

• Maximum Valve Leakage at Reseat: 5 drops/min (0.3 cc/min)

• Pilot Section Leakage (Port 2 to Port 3): 2 in³/min @ 1000 psi (32 cc/min @ 70 bar)

• Adjustment Turns (CCW to Increase Setting): 3.75

• Valve Hex Size: 1 1/8 in (28.6 mm)

• Valve Installation Torque: 45 – 50 lbf·ft (61 – 68 N·m)

• Adjustment Screw Internal Hex Size: 5/32 in (4 mm)

• Locknut Hex Size: 9/16 in (15 mm)

• Locknut Torque: 80 – 90 lbf·in (9 – 10 N·m)

• Weight: 0.60 lb (0.30 kg)

• Seal Kits: Viton (990202006)

CBEH-LDN — 10:1 Pilot Ratio, Standard Capacity Counterbalance Valve

• Product Type: 10:1 pilot ratio, standard capacity counterbalance valve

• Cavity: T-2A

• Capacity: 30 gpm (120 L/min)

• Maximum Operating Pressure: 5000 psi (350 bar)

• Pilot Ratio: 10:1

• Key Difference: Same CBEH series as CBEH-LKN; configuration variations in setting range and seal options; identical mounting interface and capacity

CWIA-LHN — 3:1 Pilot Ratio, Vented Counterbalance Valve

• Product Type: 3:1 pilot ratio, vented counterbalance valve (4-port with external drain)

• Cavity: T-24A

• Series: 4

• Capacity: 120 gpm (480 L/min)

• Maximum Operating Pressure: 5000 psi (350 bar)

• Pilot Ratio: 3:1

• Maximum Recommended Load Pressure at Maximum Setting: 3075 psi (215 bar)

• Maximum Setting: 4000 psi (280 bar)

• Check Cracking Pressure: 20 psi (1.5 bar)

• Reseat: >85% of setting

• Maximum Valve Leakage at Reseat: 5 drops/min (0.3 cc/min)

• Adjustment Turns (Min. to Max. Setting): 5

• Valve Hex Size: 1 5/8 in (41.3 mm)

• Valve Installation Torque: 350 – 375 lbf·ft (474 – 508 N·m)

• Adjustment Screw Internal Hex Size: 5/32 in (4 mm)

• Locknut Hex Size: 9/16 in (15 mm)

• Locknut Torque: 80 – 90 lbf·in (9 – 10 N·m)

• Weight: 3.52 lb (1.60 kg)

• Seal Kits: Buna (990024007) / Polyurethane (990024002) / Viton (990024006)

Key Technical Advantages

1. Sun Floating-Style Construction — Low Sensitivity to Installation Torque

The most distinctive technical advantage of Sun cartridge valves is the floating-style construction — the working assembly floats within the valve body, significantly reducing sensitivity to installation torque and preventing internal binding caused by excessive torque or cavity machining variations. This design dramatically improves field installation success rates and long-term operational reliability.

2. Standardized Cavity Design — 100% Interchangeability

• FDCB-LAN (T-5A)

• CBEH-LKN / CBEH-LDN (T-2A)

• CWIA-LHN (T-24A)

All models utilize Sun-standard threaded cartridge cavities and are fully interchangeable with genuine Sun products, enabling seamless replacement without manifold modifications — substantially reducing system retrofit and maintenance costs.

3. High-Performance Control with Low Leakage

• FDCB-LAN: Sharp-edged orifice design minimizes flow variations due to viscosity changes; leakage of only 0.8 L/min at shut-off position

• CBEH-LKN / CBEH-LDN: Reseat leakage of only 0.3 cc/min; reseat pressure exceeds 85% of set pressure

• CWIA-LHN: Reseat leakage of only 0.3 cc/min; positive seals between all ports

4. Multi-Function Integration in Counterbalance Valves

• CBEH-LKN / CBEH-LDN: Integrates counterbalance, load-holding, and motion control functions in a single cartridge, with an integrated check valve for free forward flow from port 2 to port 1

• CWIA-LHN: Vented design ensures backpressure at port 2 does not affect valve setting — the spring chamber references the vent (port 4), so backpressure is not added to the setting

5. Broad Flow and Pressure Coverage

The portfolio covers an exceptionally wide flow range — from 45 L/min (FDCB-LAN flow control) to 480 L/min (CWIA-LHN counterbalance) , with a unified maximum operating pressure of 350 bar. Whether for low-flow precision regulation or high-flow overrunning load control, a suitable model is available.

Application Areas

FDCB-LAN — Pressure-Compensated Flow Control Valve

• Precise flow regulation in meter-in or meter-out applications with wide pressure fluctuations

• Hydraulic circuits requiring constant flow supply independent of load variations

• Speed control for machine tool hydraulic systems

CBEH-LKN / CBEH-LDN — 10:1 Pilot Ratio Counterbalance Valves

• Smooth controlled lowering of overrunning loads (booms, arms, etc.)

• Cylinder position holding and load-holding

• Load control for cranes, lifts, presses, and similar equipment

• Direct installation into actuator housing cavities for added circuit protection and improved stiffness

CWIA-LHN — 3:1 Pilot Ratio Vented Counterbalance Valve

• Smooth control of high-flow overrunning loads (480 L/min capacity)

• Applications sensitive to backpressure — vented design ensures port 2 backpressure does not affect valve setting

• Boom and arm control in large construction and mining equipment

• Complex hydraulic circuits requiring vented (external drain) configuration

Target Equipment: Injection molding machines, die-casting machines, construction equipment (excavators, loaders), lifting equipment, scissor lifts, mining machinery, machine tool hydraulic systems, test benches, and more.

Expert Maintenance Tips

1. Precise Installation Torque Control

Although Sun cartridge valves feature floating-style construction to reduce torque sensitivity, installation torque specifications must still be strictly followed:

• FDCB-LAN (T-5A): 45 – 50 lbf·ft (61 – 68 N·m)

• CBEH-LKN / CBEH-LDN (T-2A): 45 – 50 lbf·ft (61 – 68 N·m)

• CWIA-LHN (T-24A): 350 – 375 lbf·ft (474 – 508 N·m)

Ensure threads are centered during installation and use a torque wrench for proper tightening.

2. Cavity and Mounting Surface Cleaning

Thoroughly clean the cavity interior and mounting surface prior to installation to remove chips, burrs, and contaminants. The shoulder stop at the bottom of the cavity supports the floating portion of the valve — ensure it is free from damage.

3. Seal Selection and Replacement

• Standard mineral oil systems: Buna-N (NBR) seals

• Phosphate ester fluid systems: EPDM seals are mandatory

• High-temperature or special media applications: Viton (FKM) seals

• Replace all cartridge seals after every disassembly

4. Fluid Cleanliness Management

Maintain system fluid cleanliness at ISO 4406 Class 18/16/13 or higher. The FDCB-LAN features a sharp-edged orifice design that is sensitive to contamination — installation of a ≤10μm return line filter is recommended for long-term reliability.

5. Counterbalance Valve Setting and Adjustment (CBEH/CWIA Series)

• Counterbalance valve setting should be at least 1.3 times the maximum load induced pressure

• Turn adjustment clockwise to decrease setting and release load

• Full clockwise setting is less than 200 psi (14 bar)

• CBEH series: Backpressure at port 2 adds to the effective relief setting at a rate of 1 plus the pilot ratio times the backpressure

• CWIA series: Vented design ensures port 2 backpressure does not affect setting — the spring chamber references the vent (port 4)

• Note: CBEH series does not have positive seals on the pilot section and will pass up to 2 in³/min @ 1000 psi between port 2 and port 3 (32 cc/min @ 70 bar). This must be considered in master-slave circuits and in leak testing of valve-cylinder assemblies

6. Periodic Functional Testing

• FDCB-LAN: Regularly verify flow setting stability and adjustment smoothness

• CBEH-LKN / CBEH-LDN / CWIA-LHN: Periodically verify smooth load lowering and check for abnormal vibration, shock, or actuator creep