Z2FS16 Z2FS10 Z2FS6 Twin Throttle Check Valve | Rexroth Series Replacement

Genlu Hydraulic proudly introduces our Z2FS Series (Z2FS6 / Z2FS10 / Z2FS16 / Z2FS22) industrial-grade, high-pressure sandwich-plate twin throttle check valves. Specifically engineered as modular flow-regulating and fluid speed-control elements, this series is widely integrated into multi-station machine tools, industrial injection molding machines, hydraulic heavy-lifting systems, and localized manifold block networks to govern the linear velocities of cylinders or rotary motors. This series serves as a premium-manufactured, performance-verified, and exact drop-in replacement for global benchmark Z2FS series (including 3X and 4X design families) pioneered by Rexroth. We specialize in supplying standard and high-flow configurations, prominently featuring the Z2FS 16-8-31/S, Z2FS16-8-3X/S, and associated factory part numbers such as R900459203.

Within sophisticated sandwich-plate multi-layer valve stacks, fine-tuning fluid flow directly governs the structural smoothness of actuator motion and eliminates stick-slip crawling. Genlu’s Z2FS valves conform rigidly to ISO 4401 standard subplate mounting interfaces. We guarantee 100% Drop-in Interchangeability across standard multi-bolt footprints, channel O-ring sealing boundaries, internal check-valve cracking pressure, and needle-valve throttling geometry. Prior to facility dispatch, each individual valve assembly undergoes 100% linear throttling flow profiling, zero-leakage check valve reverse sealing isolation checks, and continuous 31.5 MPa high-pressure anti-cavitation testing, ensuring stable speed control without flow drift under volatile work cycles.

Technical Specifications 

• Product Line: Z2FS Series Sandwich-Plate Twin Throttle Check Valve (Speed Control Module)

• Core Covered Model Formats:

  • Z2FS 16-8-31/S (Size 16, internal hex adjust screw, 31 design series, premium seal compound matrix)

  • Z2FS16-8-3X/S (Size 16, standard 3X industrial design sequence)

  • Cross-Referenced Rexroth SKU: R900459203

• Nominal Interface Sizes (Sizes): Size 6 (NG6), Size 10 (NG10), Size 16 (NG16), Size 22 (NG22)

• Maximum System Operating Pressure: 31.5 MPa (315 bar / 4570 psi)

• Maximum Permissible Volumetric Flow Ratings:

  • Z2FS6 Footprint: Up to 80 $L/min$ (21.1 GPM)

  • Z2FS10 Footprint: Up to 160 $L/min$ (42.2 GPM)

  • Z2FS16 Footprint: Up to 250 $L/min$ (66.0 GPM)

  • Z2FS22 Footprint: Up to 350 $L/min$ (92.5 GPM)

• Internal Check Valve Cracking Pressure: Standard 0.05 MPa (0.5 bar / 7.25 psi)

• Allowable Fluid Temperature Envelope: -30°C to +80°C (Standard NBR matrix; FKM Viton available for high-temperature cycles)

• Adjustment Adjustment Style: Mechanical adjustment via internal hex set-screws backed by lock nuts (optional manual scale-knob trims available)

Key Technical Advantages:

• Independent Dual-Channel A/B Port Meter-In or Meter-Out Customization: The Z2FS houses two symmetric, isolated throttle check clusters inside one housing. Operators can use two independent set-screws to separately manage fluid flow entering or leaving ports A and B. By rotating the valve body 180 degrees during installation, users can switch between meter-in and meter-out control modes, providing excellent circuit flexibility.

• High-Density Cast Iron Housing Against Fluid Turbulence: The main valve block is cast from dense, high-strength industrial cast iron. Internal oil passages are optimized using finite element flow simulation to minimize local fluid resistance under high flow rates (up to 250 $L/min$ for NG16). This reduces pressure drop and prevents heat generation from fluid shearing.

• Hardened Steel Needle Valves with Excellent Linear Fine-Tuning: The core throttle poppet pins are machined from high-grade bearing steel, vacuum hardened, and ground with micron-scale precision. The throttle ports feature a tuned geometry that produces a highly linear flow curve, enabling precise adjustment across both low micro-flows and high-volume delivery.

• Heavy-Duty, Highly Responsive Internal Check Valves: The internal check valve seats and sealing faces undergo fine grinding to ensure gas-tight, zero-leakage isolation in the reverse flow direction. High-rigidity reset springs ensure rapid, microsecond-scale closing response during directional valve shifts, preventing actuator drift or stick-slip crawling.

Application Areas:

• Heavy Duty Industrial Machine Tools & Metal Forming Equipment: Precise velocity tracking for heavy gantry milling tables, horizontal machining slides, and industrial stamping press rams.

• Industrial Injection Molding & Die-Casting Lines: Secondary speed control and fine-tuning for mold clamping, opening, and ejector cylinder hydraulic sub-circuits.

• Primary Metallurgy Machinery & Blast Furnace HPUs: Reliable tilt speed control for blast furnace ladle cylinders, steel rolling mill screw-down modules, and high-vibration heavy manifolds.

Expert Maintenance Tips:

• Strictly Verify Meter-In vs. Meter-Out Orientation Prior to Final Bolting: The Z2FS is a symmetrical modular design. By flipping the valve body 180 degrees along its horizontal axis (reversing the top and bottom faces marked with A/B channels), you alternate between Meter-In and Meter-Out control. Before tightening the tie-rod bolts, always double-check that the cast flow arrows on the valve casing match your circuit design, or your speed control logic will be reversed.

• Tighten Stack Tie-Rods Evenly Using a Calibrated Torque Wrench: As a sandwich-plate element, the Z2FS is clamped between the base manifold and the top directional solenoid valve. When installing long, high-tensile tie-rods through the valve stack, you must use a torque wrench to tighten the nuts in a crosswise pattern using gradual increments. Uneven tightening or over-torquing can warp the cast iron housing, which can cause internal spool binding in the top solenoid valve or lock up the throttle adjustment pins.

• Securely Torque the Lock Nut After Finalizing Flow Settings: Once you have dialed in the correct throttling screw positions to match your production cycle, tighten the outer mechanical lock nuts down securely. If left loose under high-frequency system vibrations, the adjustment screws can creep over time, causing irregular cycle speeds and flow drift.