DG5V-8 Eaton Vickers Directional Valve 700 L/min 350 Bar

Product Overview

The DG5V-8 series pilot-operated directional valves (including models DG5V-8-H-6C-2-M-U-B-10, DG5V-8H-1C-T-S-M-FW-D-10, and DG5V-8-S-6C-M-U-H-10) are manufactured to original Eaton Vickers technical standards. Belonging to the DG5V-8 series with size 08 (NG25 / CETOP 8 / ISO 4401-08 / NFPA D08), these valves are high-performance two-stage solenoid-controlled pilot-operated directional control valves. Featuring a pilot-operated two-stage design with a high-performance DG4V-3 series solenoid pilot valve, the main spool is positioned by pilot pressure. The mounting surface conforms to ISO 4401-08 standards, used for controlling the starting, stopping, and direction of fluid flow in high-flow hydraulic systems.

The DG5V-8-H-6C-2-M-U-B-10 features spool type 6C (P blocked, A & B to tank in center), spring centered, equipped with a high-performance pilot valve (H type) and integrated pilot choke module (type 2), 10 design. The DG5V-8H-1C-T-S-M-FW-D-10 features spool type 1C (P, A & T interconnected, B blocked in center, open center), spring centered, equipped with a standard performance pilot valve (S type) and FW type wiring housing, 10 design. The DG5V-8-S-6C-M-U-H-10 features spool type 6C (P blocked, A & B to tank in center), spring centered, equipped with a standard performance pilot valve (S type) and 24 VDC wet-pin solenoids.

All models deliver maximum main stage flow of 700 L/min (185 USgpm) at 350 bar (5075 psi). Pilot valve tank line pressure rating is 210 bar (3000 psi) for H type and 100 bar (1450 psi) for S type. Solid cast bodies and cored passages provide maximum strength and minimal pressure drop.

These products are dimensionally and functionally identical to the original Eaton Vickers DG5V-8 series valves. The DG3V and DG5V are 100% interchangeable with previous H8 design valves, enabling direct drop-in replacement without modifying piping or control programs. Every unit undergoes 100% bench testing under simulated working conditions, including rated pressure holding, directional response verification, internal leakage measurement, and solenoid response characterization.

Technical Specifications 

General Specifications

• Model: DG5V-8-H-6C-2-M-U-B-10 / DG5V-8H-1C-T-S-M-FW-D-10 / DG5V-8-S-6C-M-U-H-10

• Product Series: DG5V-8 (Size 08 / NG25 / CETOP 8 / ISO 4401-08 / NFPA D08)

• Design Number: 10 Design

• Spool Type: 6C (P blocked, A & B to tank in center, spring centered) / 1C (P, A & T interconnected, B blocked in center, spring centered)

• Design: Solenoid controlled, pilot operated, two-stage directional control valve

• Mounting Pattern: ISO 4401-08 / CETOP 8 / NFPA D08

• Installation Position: Spring centered/offset: unrestricted; Detent: horizontal

Hydraulic Parameters

• Maximum Flow Rate: 700 L/min (185 USgpm)

• Maximum Operating Pressure (Ports P/A/B/T): 350 bar (5075 psi)

• Pilot Valve Tank Line Pressure Rating: H type 210 bar (3000 psi) / S type 100 bar (1450 psi)

• Hydraulic Fluid: Mineral-based hydraulic oil, water glycol, water-oil emulsion

• Standard Seals: Viton (FKM) / Buna-N (NBR)

• Fluid Temperature Range: -20°C to +80°C

• Filtration: ISO 4406 19/17/14

• Main Stage Return: Spring centered (6C / 1C)

• Pilot Choke: Type 2 (DG5V-8-H-6C-2-M-U-B-10 model)

• Endurance: Tested to 10 million cycles per NFPA fatigue specifications

Pilot Control Parameters

• Pilot Valve Model: DG4V-3 series high-performance pilot valve (H type) / standard performance pilot valve (S type)

• Pilot Valve Size: 03 (NG6 / CETOP 3)

• Pilot Valve Maximum Flow: 80 L/min

• Pilot Supply: Internal

• Pilot Drain: External

Electrical Parameters

• Supply Voltage: 24 VDC (H coil) / 110V AC 50Hz / 120V AC 60Hz (B coil)

• Solenoid Type: Wet armature solenoid with interchangeable coil

• Electrical Connector: ISO 4400 (DIN 43650) standard connector (U type) / FW type wiring housing

• Protection Class: IP65 (with standard connector)

• Manual Override: Plain manual override standard; waterproof and lockable optional

• Coil Insulation: Class H

• Duty Cycle: Continuous (ED = 100%)

Materials & Construction

• Valve Body: Solid cast body with cored passages for maximum strength and minimal pressure drop

• Control Spool: Carburized steel, precision ground

• Seals: Viton (FKM) / Buna-N (NBR)

• Surface Treatment: Phosphating / anti-corrosion coating

Weight

• Approx. 20.0 lbs (approx. 9.1 kg)

Key Technical Advantages

1. High Flow Capacity with Low Pressure Drop
The DG5V-8 series delivers up to 700 L/min (185 USgpm) flow capacity in size 08 at 350 bar (5075 psi) maximum operating pressure. Solid cast bodies and cored passages provide maximum strength and minimal pressure drop, effectively reducing system energy loss. The main stage spool features spring-centered design, ensuring reliable spool return to the center position upon solenoid de-energization for a safe system state.

2. High-Performance Pilot Valve with High Tank Line Pressure Rating
The series offers an optional H type (DG4V-3-60) high-performance pilot valve with a tank line pressure rating of 210 bar (3000 psi), significantly higher than the S type standard performance pilot valve rating of 100 bar (1450 psi). High force solenoids and centering springs assure consistent shifting through a wide range of pressure and silting extremes. When pilot pressure exceeds 210 bar, a reducer module is required.

3. Multiple Spool Options for Flexible Circuit Design
The DG5V-8 series offers multiple interchangeable spool functions: 6C (P blocked, A/B to T, motor spool), 1C (P/A/T interconnected, B blocked, open center), type 0 (open center all ports), type 2 (closed center), type 3 (P & B blocked, A to T), type 4 (tandem center P→T, closed crossover), type 7 (P→A & B, T blocked), type 8 (tandem center P→T, open crossover), and others. The multiple function combinations meet diverse hydraulic circuit design requirements.

4. Pilot Choke Module for Smooth Shifting
The DG5V-8-H-6C-2-M-U-B-10 features a type 2 pilot choke module that controls the main spool shift speed by adjusting the pilot oil circuit throttling, effectively reducing hydraulic shock and pressure peaks in the circuit for smooth shifting. This module is particularly suitable for applications sensitive to shifting shock, significantly extending system component life.

5. Durability-Tested High Reliability Design and Drop-in Interchangeability
The DG5V-8 series valves have been endurance tested to 10 million cycles and fatigue tested to NFPA standards, ensuring the highest reliability in high flow and pressure applications. The DG3V and DG5V are 100% interchangeable with previous H8 design valves, enabling direct drop-in replacement without modifying piping or control programs. Every valve undergoes 100% bench testing prior to shipment, covering rated pressure holding, directional response time measurement, internal leakage verification, and solenoid response characterization.

Application Areas

• Die Casting Machines: High-flow directional control for shot systems, suitable for UBE die casting machines and similar large equipment

• Injection Molding Machines: Directional control for large injection molding machine mold closing, injection, and ejector high-flow hydraulic circuits

• Hydraulic Presses: Main cylinder directional control and fast/slow speed switching for medium-to-large tonnage presses

• Metallurgical Equipment: High-flow directional control for continuous casting machines and rolling mill auxiliary hydraulic systems

• Construction Machinery: Main hydraulic circuit directional control for excavators and cranes

• Marine Hydraulics: Steering gear control and deck machinery high-flow directional control

• Testing Equipment: Hydraulic loading direction control for large material testing machines

• Wind Power Generation: Pitch control system hydraulic directional control

Expert Maintenance Tips

Installation Guidelines

1. For the DG5V-8 series, spring-centered models have unrestricted mounting positions; detent models (no-spring mechanical detent) must be installed with the valve spool in the horizontal position for good machine reliability. Mounting surface flatness must be ≤ 0.05 mm. Tighten mounting bolts diagonally in stages to the specified torque value. The mounting surface conforms to ISO 4401-08 for direct installation on standard subplates or manifolds.

2. Thoroughly flush all piping circuits before installation. Recommended cleaning methods are sandblasting, wire brushing and pickling. Prior to first operation, circulate the system through a 10 μm filter element for a minimum of 30 minutes.

3. Y-Port (Pilot Drain) Management: This valve uses external pilot drain. The Y-port must be piped directly to the tank; back pressure cannot be tolerated at this valve port. When pilot pressure exceeds 210 bar (3000 psi), a reducer module is required.

4. Electrical Grounding: On solenoid operated directional valves, ensure an electrical ground is connected to the valve to prevent the possibility of a shock hazard if a coil develops a short circuit to the frame. Electrical connections must use a U type connector conforming to ISO 4400/DIN 43650 to maintain IP65 protection. Control signal cables should be shielded, with the shield grounded at one end.

Routine Maintenance Procedures

1. Fluid Cleanliness Management: Maintain system fluid cleanliness at ISO 4406 19/17/14 or better. Check fluid particulate contamination every 500 operating hours and replace filter elements and hydraulic fluid when contamination exceeds limits. Ensure the entire system is flushed to remove paint, metal chips, welding shot, etc..

2. Pilot Valve Maintenance: Periodically inspect the DG4V-3 series pilot stage for proper operation and stable pilot pressure. Pilot valve tank line pressure must not exceed 210 bar (H type) or 100 bar (S type). If main stage shifting is abnormal, first check the pilot valve filter for blockage.

3. Solenoid Electrical Inspection: Periodically inspect connectors for seal integrity and terminal tightness. Measure coil resistance and replace the coil if deviation exceeds ± 10%. Plain manual overrides are standard; waterproof and lockable manual overrides are optional.

4. Pilot Choke Maintenance: The type 2 pilot choke module of the DG5V-8-H-6C-2-M-U-B-10 can be adjusted via the adjusting screw to control main spool shift speed. To adjust, back off the lock-nut, slowly turn the adjusting screw, and re-tighten after adjustment. Adjustments should only be conducted by trained specialists.

5. Shifting Performance Verification: Periodically check each position for smooth shifting and absence of binding. If shifting response becomes sluggish or internal leakage increases, inspect spool wear and fluid contamination levels.

6. Seal Replacement: Standard Viton (FKM) or Buna-N (NBR) seals. For phosphate ester fluids, F3 seals are required; for water-glycol, F6 seals are available. Under normal operating conditions, replace valve seals every 3,000-5,000 operating hours.