Rexroth DA6V Series Pressure Cut-off Valve DA6VP2B-5X/350FSM DA6VA2B DA6VA1

The premium DA6V Series Pilot-Operated Pressure Cut-Off Valves (encompassing standard electro-hydraulic configurations DA6VP2B-5X/350FSM, DA6VA2A, DA6VA2B, DA6VA1, DA6VA2, and DA6VA3) manufactured by Chengyuan Hydraulic represent industrial-grade fluid power regulation components engineered for 100% direct drop-in interchangeability within the control networks of heavy-duty high-pressure axial piston pumps (such as A4VSO, A4VG, or A11VLO series). Fabricated in meticulous structural conformity with Bosch Rexroth DA6V (Series 5X) application manuals, this product line perfectly matches original subplate mounting footprints, control port dimensions, and thread standards. B2B global industrial procurement networks can execute immediate, seamless on-site component swaps inside pump control blocks with zero manifold or piping redesign.

Operating as the reliable pressure protection watchdog for high-displacement hydrostatic drive systems, the DA6V series limits system pressure spikes through integrated pilot-operated pressure cut-off mechanisms. When the system fluid reaches a predefined pressure threshold, the valve strokes instantly to destroke the main piston pump, safeguarding expensive high-pressure components from destructive hydraulic line shocks. The DA6VP configuration incorporates a robust wet-pin directional solenoid valve as its pilot stage for digital electronic integration, whereas the DA6VA sub-series relies on pure hydraulic or proportional pilot lines to fit varied plant automation setups. At Chengyuan, all operational risks are eliminated through our 100% rigorous dynamic simulation test bench criteria. Every valve must maintain precise volumetric integrity, millisecond response curves under a continuous 350 bar load, and low hysteresis signatures before factory sign-off.

Technical Specifications

• Product Series Classification: DA6V Series Pilot-Operated Pressure Cut-off Valve (Series 5X)

• Nominal Valve Port Size: NG06 / CETOP 03 / NFPA D03

• Structural Material: Monoblock high-density ductile iron valve body

• Nominal Continuous Operating Pressure: 350 bar (35 MPa)

• Maximum Permissible Peak Pressure: 400 bar (40 MPa)

• Maximum Control Flow Rate: Approx 40 L/min

• Recommended Fluid Medium: Premium anti-wear mineral-based hydraulic oils (ISO 4406 20/18/15 minimum)

• Model-Specific Nomenclature & Engineering Metrics:

  • Model Designation: DA6VP2B-5X/350FSM

  • DA6VP: Pilot-operated pressure cut-off valve utilizing a solenoid-actuated directional spool pilot stage.

  • Control Configuration 2B: Specific internal spring-return logic and pilot spool configuration (normally open/normally closed cut-off options).

  • Technical Generation: Series 5X (Interchangeable across all 50-to-59 legacy editions).

  • Upper Pressure Limit 350: Maximum calibrated setting threshold up to 350 bar.

  • Hardware Code FSM: Specially designated solenoid block (e.g., 24V DC) outfitted with an emergency manual override pin and high-integrity Viton seal rings.

  • Net Weight: Approx 2.2 kg.

  • Model Designations: DA6VA2A / DA6VA2B

  • DA6VA: Pure hydraulically operated pressure cut-off pilot stage (independent of electrical coils; controlled entirely via internal or external pilot oil grids).

  • Control Configuration 2A/2B: Denotes specific pilot channel extraction routing tailored for direct interface onto forward or reverse pump swashplate centering mechanisms.

  • Continuous Working Pressure: 350 bar rating.

  • Net Weight: Approx 1.6 kg.

  • Model Designations: DA6VA1 / DA6VA2 / DA6VA3

  • Control Scales 1 / 2 / 3: Represents variable preset upper-limit pressure scales or precision-drilled pilot internal orifices designed to alter the stroking time-delay constant, mitigating harmonic fluid resonance inside pilot lines.

  • Maximum Operating Threshold: 350 bar nominal / 400 bar peak pressure.

  • Net Weight Range: Approx 1.5 to 1.8 kg.

Key Technical Advantages

• Micron-Precision Shaved Spools for Low Hysteresis Shifting: The primary and pilot valve spools are machined from vacuum-treated hardened alloy steel, finished via precision CNC cylindrical grinding. Internal clearances are kept between 2 to 4 microns. This micro-tolerance structure ensures low sliding friction under a full 350 bar load, maintaining regulation hysteresis at $\le 1\%$.

• Sharp and Smooth Pressure Cut-off Characteristics: The internal flow paths are optimized via CFD modeling, enabling the valve to instantly destroke the main pump’s variable swashplate once the pressure threshold is tripped. This sharp limitation response provides fast overload protection while utilizing targeted dampening profiles to cushion the system against fluid spikes.

• High-Density Anti-Deformation Ductile Iron Cast Enclosure: The primary valve housing is cast as a single block from high-tensile ductile iron. Under severe 400 bar cyclic loading, the structural deflection of the internal 5-chamber matrix is virtually zero. This preserves precise coaxial alignment, preventing internal leakage and stopping spool sticking.

• High-Fatigue Calibrated Pressure Setting Springs: The mechanical adjustment spring sets are wound from high-stress alloy valve-spring steel, verified to pass millions of loading cycles without setting a permanent deformation. Paired with a secure mechanical locking adjust screw, the pressure cut-off threshold remains locked despite continuous plant-floor shock loads.

Application Areas

The DA6V series pilot pressure cut-off valve operates primarily as the safety regulation module integrated onto high-pressure axial piston pumps within critical electro-hydraulic systems:

• Heavy-Duty Heavy Industrial Hydraulic Power Units: Primary variable pump control manifolds (A4VSO series etc.) for steel rolling mills, high-pressure forging press blocks, and central power generation servo grids.

• Tunnel Boring & Sub-Surface TBM Equipment: Real-time overpressure safety protection modules for primary piston pump arrays driving tunnel boring machine cutter-heads.

• High-Tonnage Mobile Construction Machinery: Main winch hydrostatic loop protection for crawler cranes, heavy-duty piling rigs, and high-capacity rotary mining drills.

Expert Maintenance Tips

• Always Deploy High-Accuracy Gauges During Calibration: When adjusting the mechanical pressure limits on the DA6VP2B-5X/350FSM or DA6VA valves, monitor the test port using a dampening pressure gauge. Never adjust the regulation screw blind; over-tightening can overload the system and cause catastrophic failure of the main pump or motor.

• Enforce Rigid Fluid Cleanliness Regimes to Prevent Blockage: Because the DA6V series utilizes internal pilot orifices as small as $\phi 0.6 – \phi 1.0\,\text{mm}$, small metal flakes or silt can plug the channels, causing the cut-off mechanism to lock up. It is highly recommended to install a high-pressure inline filter rated at $\le 10\,\mu\text{m}$ upstream of the control port.

• Conduct Regular Voltage Assessments on the Solenoid Pilot Stage: For the solenoid-driven DA6VP variants, verify that the input DC supply tracks within $\pm 10\%$ of nominal specifications. In high-temperature or high-vibration mobile environments, clean the electrical connections routinely to eliminate oil film ingress, which can cause coil short-circuiting.