PDF Stacked Pre-fill Valve | PDF-80 PDF-90 PDF-100 | Full Oil Valve PDF-50 to PDF-200 | Hydraulic Filling Valve

PDF Series Stacked Hydraulic Pre-fill Valves (Full Oil Valves)

Product Overview:

The PDF series is a high-performance, stacked-style pre-fill valve specifically engineered for the rapid filling and exhausting of oil in large hydraulic cylinders. During the rapid downward stroke of a press, the PDF valve allows large volumes of oil to be drawn from the tank into the main cylinder cavity. In the return stroke, pilot pressure opens the valve to facilitate high-speed oil discharge. Its Stacked configuration not only saves significant piping space but also enhances system integration and response speed. The PDF series is an essential component for achieving “Fast-Forward, High-Pressure, Fast-Retract” logic in metal forming presses, injection molding machines, and heavy-duty hydraulic equipment.

Featured models: PDF-80-20, PDF-90-20, PDF-100-20, and the full range from PDF-50 to PDF-200-20.

Key Technical Advantages:

• Exceptional Flow Efficiency: Large-diameter flow passages minimize fluid resistance, ensuring rapid large-volume filling and exhausting to optimize machine cycle times.

• Compact Stacked Design: Unique vertical stacking allows direct mounting between the cylinder and the main control valve, significantly reducing installation footprint and potential leak points.

• Hermetic Sealing Performance: Utilizing high-hardness alloy steel spools with precision-ground fits, the valve ensures zero-leakage closure under high pressure, maintaining system stability.

• Smooth Pilot Control: Optimized pilot opening ratios ensure minimal shock during the initial opening phase, protecting hydraulic lines from vibration damage.

• Comprehensive Size Range: Available in sizes from NG50 to NG200, perfectly matching the requirements of various cylinder tonnages.

Detailed Specifications & Parameters:

• Featured Model Matrix:

  • PDF-80/90/100: Mainstream specifications for medium-to-large presses, balancing flow and response.

  • PDF-125/150/200: Ultra-high flow specifications for heavy-duty, thousand-ton hydraulic presses.

  • -20 Series: Represents the latest design generation with optimized spool guidance.

• Core Technical Specs:

  • Max Operating Pressure: 25 MPa (250 bar) to 31.5 MPa (315 bar).

  • Pilot Opening Pressure: Typically $1/3$ of the system pressure or based on spring configuration.

  • Fluid Compatibility: Anti-wear hydraulic oils (ISO VG32/46).

  • Installation: Recommended vertical or horizontal mounting at the cylinder head.