CPDG-10-20-60 CPDG-03-04-50 Yuken Pilot Check Valve 25 MPa

Product Overview

The CPG/CPDG and CPT/CPDT series pilot-operated check valves are core hydraulic control components from the Yuken brand family. These valves allow free flow in one direction and, when operated by pilot pressure, open the poppet to enable free reverse flow.

The series covers the following major product lines:

• CPG Series: Subplate-mounted pilot-operated check valves

• CPDG Series: Subplate-mounted decompression type pilot-operated check valves — releasing trapped pressure before fully opening the main poppet to eliminate hydraulic shock

• CPT Series: Threaded connection pilot-operated check valves

• CPDT Series: Threaded connection decompression type pilot-operated check valves

Key models covered include:

• CPDG Series: CPDG-10-20-60, CPDG-03-04-50, CPDG-06-04-50, CPDG-10-04-50, etc.

• CPG Series: CPG-03-04-50, CPG-06-04-50, CPG-10-04-50, etc.

• CPT Series: CPT-03-04-50, CPT-06-04-50, CPT-10-04-50, etc.

• CPDT Series: CPDT-03-04-50, CPDT-06-04-50, CPDT-10-04-50, etc.

Model code breakdown (using CPDG-10-20-60 as an example):

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

Technical Specifications 

CPDG / CPG Series (Subplate Mounting)

• Series: CPG / CPDG Pilot-Operated Check Valve

• Connection Type: Subplate mounting

• Nominal Sizes: 03 / 06 / 10

• Maximum Operating Pressure: 25 MPa (250 bar)

• Cracking Pressure Options: 0.04 / 0.20 / 0.35 / 0.50 MPa

• Rated Flow:

  • Size 03: 40 L/min

  • Size 06: 125 L/min

  • Size 10: 250 L/min

• Weight:

  • CPG-03 / CPDG-03: 3.0 – 3.3 kg

  • CPG-06 / CPDG-06: 5.4 – 5.5 kg

  • CPG-10 / CPDG-10: 8.5 – 9.6 kg

• Mounting Bolts:

  • Size 03: M10 × 45L, 4 pcs

  • Size 06: M10 × 50L, 4 pcs

  • Size 10: M10 × 55L, 6 pcs

• Body Material: Cast Iron

• Seal Material: NBR (standard) / FKM (for phosphate ester fluids)

• Hydraulic Fluid: Mineral oil (per DIN 51524); Phosphate ester fluids (specify FKM seals)

• Temperature Range: -20℃ to +80℃

CPDT / CPT Series (Threaded Connection)

• Series: CPT / CPDT Pilot-Operated Check Valve

• Connection Type: Threaded connection

• Nominal Sizes: 03 / 06 / 10

• Maximum Operating Pressure: 25 MPa (250 bar)

• Cracking Pressure Options: 0.04 / 0.20 / 0.35 / 0.50 MPa

• Rated Flow:

  • Size 03: 40 L/min

  • Size 06: 125 L/min

  • Size 10: 250 L/min

• Weight:

  • CPT-03 / CPDT-03: 3.0 kg

  • CPT-06 / CPDT-06: 5.5 kg

  • CPT-10 / CPDT-10: 9.6 kg

• Body Material: Cast Iron

• Seal Material: NBR (standard) / FKM (for phosphate ester fluids)

• Hydraulic Fluid: Mineral oil (per DIN 51524); Phosphate ester fluids (specify FKM seals)

• Temperature Range: -20℃ to +80℃

Key Technical Advantages

1. Pilot-Operated Design for Controlled Reverse Flow

The CP/CPD series pilot-operated check valves add pilot control functionality to conventional check valves — when pilot pressure acts on the poppet, it opens the seat valve that is held closed by outlet port pressure, enabling free reverse flow. This design makes them indispensable in load-holding and controlled-release applications.

2. Decompression Type Design to Eliminate Hydraulic Shock

The CPDG and CPDT series (with “D” designation) feature a decompression type design — releasing trapped pressure before fully opening the main poppet. This unique two-stage opening characteristic effectively eliminates hydraulic shock caused by sudden pressure release in high-pressure locked circuits, protecting system piping and actuators from pressure spikes.

3. Multiple Cracking Pressure Options for System Flexibility

Cracking pressure is available in four standard options: 0.04 / 0.20 / 0.35 / 0.50 MPa. Users can select based on system backpressure and response requirements — lower cracking pressure for low-backpressure systems requiring sensitive response; higher cracking pressure for high-backpressure systems to prevent unintended opening.

4. Internal/External Pilot Drain Options for Complex Backpressure Conditions

Standard models feature internal drain configuration. When backpressure exists at the outlet during reverse free flow, external drain (marked with “E” in the model number) is mandatory. External drain design ensures pilot pressure is not affected by outlet backpressure, guaranteeing reliable poppet opening.

5. Broad Size Coverage for Diverse Flow Requirements

The CP/CPD series covers three sizes — 03 (3/8″), 06 (3/4″), 10 (1-1/4″) — with flow ranges from 40 L/min to 250 L/min. Whether for low-flow precision control or high-flow system pressure-holding, a suitable model is available.

Application Areas

• Cylinder Position Holding and Load-Holding: Locks actuator ports when the directional valve is in neutral, preventing load drift or creeping

• Hydraulic System Pressure-Holding Circuits: Provides reliable pressure retention in systems requiring long-term pressure maintenance

• Counterbalance Circuits: Combined with throttle or counterbalance valves for smooth controlled lowering of overrunning loads

• Hydraulic Valve Stack Integration: As a core component for directional control and load-holding, combined with directional valves, throttle valves, and other components on integrated manifolds

• Target Equipment: Injection molding machines, die-casting machines, construction equipment (excavators, loaders), lifting equipment, scissor lifts, machine tool hydraulic systems, metallurgical equipment, and more

Expert Maintenance Tips

1. Mounting Surface Cleaning: Thoroughly clean the mounting surface and all ports prior to installation to remove oil residue, chips, and contaminants. Inspect all O-ring seal grooves on the mounting surface for damage.

2. O-Ring Replacement: Replace all O-ring seals on the mounting surface after every disassembly. Use NBR seals for standard mineral oil systems; EPDM or FKM seals are mandatory for phosphate ester fluids — specify “F-” prefix in the model number.

3. Mounting Bolt Torque Control:

   • Size 03: M10 × 45L bolts, 4 pcs

   • Size 06: M10 × 50L bolts, 4 pcs

   • Size 10: M10 × 55L bolts, 6 pcs
     Tighten in a diagonal sequence in gradual increments to avoid valve body distortion or seal failure from over-tightening on one side.

4. Pilot Drain Type Selection:

   • Outlet connected directly to tank during reverse free flow: Use internal drain (standard type, no “E” marking) 

   • Backpressure exists at the outlet during reverse free flow: External drain (marked with “E”) is mandatory

5. Minimum Pilot Pressure Verification: Verify that system pilot pressure meets the valve’s opening requirement before installation. Insufficient pilot pressure will result in incomplete poppet opening, causing throttling heat generation and pressure loss.

6. Fluid Cleanliness Management: Maintain system fluid cleanliness at ISO 4406 Class 18/16/13 or higher. Install a filter with ≤10μm rating in the return line where feasible.

7. Periodic Functional Testing: Test the pilot check valve locking and opening functions every 2,000 operating hours or annually. If the actuator fails to hold position reliably (creeping, drifting) or exhibits abnormal shifting behavior, disassemble and inspect the poppet and seat for wear — replace the cartridge assembly if necessary.