Tokyo Keiki DG5V Series Reversing Valve | DG5VC-7 DG5V-H8 Solenoid Pilot Operated Valve | High Flow Hydraulic Control

The DG5V Series solenoid-controlled, pilot-operated reversing valves from Chengyuan Hydraulic are high-performance components engineered as premium replacements for Tokyo Keiki (Tokimec) standards. Designed for heavy-duty hydraulic systems requiring massive flow rates and high pressure, this series features core models such as the DG5VC-7 (NG16) and DG5V-H8 (NG25). As a two-stage valve, it utilizes a solenoid-operated pilot valve to drive the main spool, enabling smooth directional control of high-volume fluid. Chengyuan ensures 100% Drop-in Interchangeability with original Tokyo Keiki units in terms of ISO 4401 mounting patterns, spool functions, and response timing. All valves undergo 100% Simulation Load Testing at pressures up to 31.5 MPa to guarantee minimal leakage and superior switching reliability under extreme duty cycles.

Technical Specifications

• Compatible Brand: Tokyo Keiki (Tokimec)

• Model Codes: DG5VC-7-2C-T-PGN2-H-86-JA / DG5V-H8-3C-E-P2-T-86-JA192

• Nominal Sizes: NG16 (Size 7) / NG25 (Size 8/H8)

• Max. Operating Pressure: 31.5 MPa (315 Bar) / Up to 35 MPa for H-Series

• Max. Flow Rate: Approx. 300 L/min for DG5V-7; Up to 1100 L/min for DG5V-H8

• Pilot Pressure Range: 1.0 MPa to 21 MPa (Depending on spring settings)

• Coil Voltage Options: AC110V, AC220V, DC24V

• Mounting Type: Subplate Mounting (ISO 4401 compliant)

• Spool Functions: 2C (Closed Center), 3C (Open Center), and various other configurations

• Pilot/Drain Options: Internal/External Pilot, Internal/External Drain (T/E/ET configurations)

Key Technical Advantages:

• Two-Stage Damping Design: By optimizing the hydraulic pilot drive logic, the DG5V series reduces hydraulic shock during high-flow switching. This “soft-shift” capability protects piping and reduces machine vibration significantly.

• Precision-Honed Spool Fit: The main spool and valve body are matched via micron-level honing for perfect concentricity. This prevents spool sticking due to thermal expansion or lateral forces, even during continuous operation at 31.5 MPa.

• Versatile Pilot Control Features: Supports configurations like P2 (Pressure Reducer) and PGN (Orifice Adjustment). Users can fine-tune the spool stroke speed to achieve precise control over large actuators like heavy-duty cylinders.

• High-Efficiency Flow Channels: The valve body is cast using specialized processes to ensure wide, smooth internal galleries. This minimizes pressure drop (ΔP) across the valve, enhancing overall system energy efficiency.

Application Areas:

• Metallurgical Machinery: Main power units for continuous casters and rolling mills in steel plants.

• Heavy Presses: Control valves for metal scrap balers and large-scale hydraulic stamping presses.

• Plastic Injection Molding: Primary circuits for clamping and injection in large-tonnage machines.

• Marine Engineering: Reliable directional control for steering gears and deck machinery.

Expert Maintenance Tips:

• Pilot Circuit Filtration: 90% of valve failures are due to contamination. Since pilot orifices are very small, keep the system fluid cleanliness at NAS Grade 8 or ISO 4406 19/17/14.

• Minimum Pilot Pressure: Ensure the pilot pressure is at least 1.0 MPa higher than the tank line backpressure. Insufficient pilot pressure will prevent the spool from completing its full stroke, leading to sluggish actuator response.

• Air Bleeding Protocol: During commissioning or after valve replacement, loosen the air bleed screws on the pilot stage. Trapped air can cause “crawling” or irregular delay during spool transitions.