Rexroth M-3SED6 M-3SED10 Directional Seat Valve | Solenoid Operated Leak-Free Poppet Valve Replacement

Genlu Hydraulic proudly introduces our industrial fleet-grade M-3SED Series (comprehensively covering NG6 and NG10 displacement nodes) direct-operated solenoid-actuated directional seat valves (poppet type). Specifically engineered to achieve dynamic zero internal leakage, long-duration pressure holding, and fast high-frequency switching response, this series serves as a premium, high-value drop-in replacement for the classic Bosch Rexroth (M-3SED) industrial platform. It adapts flawlessly to replace high-specification engineering models such as M-3SED6CK13/350CG24N9K4 and M-3SED10CK13/350CG24N9K4.

The structured alphanumeric nomenclature defines its advanced technical configuration: M-3SED identifies it as a direct solenoid poppet seat valve; 6/10 dictates the ISO 4401 subplate mounting size (NG6/CETOP 3 or NG10/CETOP 5 interface); C designates the 3/2-way normally closed (NC) functional spool layout; K13 specifies an integrated damping cushion with an internal check valve/orifice plug; 350 declares a heavy-duty continuous rating of $35.0 \text{ MPa}$; C indicates a heavy-duty corrosion-resistant wet pin solenoid variant; G24 signifies standard DC 24V actuation; and K4 identifies the inclusion of a heavy-duty manual override pin with a standard rectangular DIN connector.

Unlike traditional sliding spool valves that suffer from clearance bypass leakage, this seat valve utilizes Rexroth’s signature ball-on-seat (or cone-on-seat) mechanical interference seal matrix, achieving true physical fluid isolation when closed. Genlu guarantees 100% Drop-in Interchangeability across standard subplate mounting dimensions (ISO 4401 compliant), alignment dowel layouts, fixing bolt matrices, and electrical plug configurations compared to original Rexroth assemblies. Every single seat valve undergoes a rigorous 100% automated inspection protocol on our digital benches, certifying exact switching times and absolute leak-free isolation under full 35.0 MPa pressure holding tests.

Technical Specifications 

• Product Series: M-3SED Series Direct-Operated Solenoid Directional Seat/Poppet Valve (Subplate Mounting)

• Core Model Identifiers: M-3SED 6 C, M-3SED 10 C (Primary configurations: M-3SED6CK13/350CG24N9K4, M-3SED10CK13/350CG24N9K4)

• Valve Size Configuration:

  • M-3SED 6 Frame: NG6 (Standard ISO 4401-03 / CETOP 3 mounting interface)

  • M-3SED 10 Frame: NG10 (Standard ISO 4401-05 / CETOP 5 mounting interface)

• Circuit Spool Configuration: 3-Way, 2-Position (3/2-Way), Normally Closed (C Type) baseline geometry

• Maximum Operating Pressure Threshold: $35.0 \text{ MPa}$ ($350 \text{ bar} / 5075 \text{ psi}$ full pressure rating across all ports, including T)

• Maximum Permissible Flow Capacity:

  • NG6 Variant: Rated up to $45 \text{ L/min}$

  • NG10 Variant: Rated up to $100 \text{ L/min}$

• Solenoid Electrical Core: Heavy-duty DC 24V (G24) wet-pin, detachable high-response coil assembly

• Operating Fluid Temperature Range: $-30^\circ\text{C}$ to $+80^\circ\text{C}$ (Standard NBR nitrile sealing matrix)

• Switching Damping Matrix: Integrated K13 internal buffer assembly to absorb fast fluid-hammer shocks

• Static Internal Leakage Boundary: $0 \text{ drops/min}$ (Hermetic bubble-tight seal at full 35.0 MPa load)

Key Technical Advantages:

• Hard-On-Hard Ball-Seat Interference Sealing Matrix: The internal valve core replaces traditional sliding sleeves with a high-rigidity chrome steel ball (or cone poppet) mating against a precision-ground seat. When closed, internal system fluid pressure hydrostatically presses the ball tighter into the seat, achieving zero internal bypass leakage. This configuration makes it ideal for long-duration accumulator lockouts and hydraulic clamping configurations.

• Fully Balanced Hydraulic Poppet Core Configuration: The internal flow paths are hydrostatically optimized for dynamic pressure balance. Regardless of high-frequency pressure spikes across the A, B, P, or T ports, the axial fluid forces acting on the poppet core are canceled out. This design eliminates unbalanced hydrodynamic resistance, allowing the solenoid to open and close smoothly under max-flow conditions without binding.

• Wet-Pin Detachable DC Solenoid with Transience Suppression: The DC 24V coil uses an industrial wet-pin design where the core armature is submerged fully in the system fluid for rapid thermal dissipation and internal cushioning. The integrated square connector houses dual-path Transient Voltage Suppression (TVS) diodes that clip inductive back-EMF spikes during coil de-energization, fully safeguarding upstream PLC control cabinets.

• High-Grade Monoblock 35.0 MPa T-Port Pressure Casting: The main valve body is cast from heavy-duty ductile iron using specialized three-dimensional internal core molding. This layout allows every port—including the return T-port, which is traditionally vulnerable in sliding spools—to continuously withstand full 35.0 MPa pressure. This allows the valve to be utilized seamlessly in complex stacked circuits where the T-port is routed as a pressure feed to downstream blocks.

Application Areas:

• CNC Machine Tool Fixtures & Central Clamping Systems: Long-duration clamping blocks for workholding chucks, and flexible hydraulic power units for automated machining centers.

• Automated Hydraulic Safety Systems & Accumulator Blocks: Emergency yaw and rotor braking stations for wind turbines, safety lockout manifolds for heavy stamping presses, and energy-saving power units requiring prolonged pressure holding.

• Mobile Fleet Auxiliary Locking Circuits: Hydrostatic parking brake release manifolds for asphalt compactors, and hydraulic rail-clamping safety blocks for heavy-duty hoists.

Expert Maintenance Tips:

• Enforce Rigid Mounting Flatness Thresholds and Use Uniform Diagonal Bolt Torque: The internal tolerances of the M-3SED series require a subplate mounting surface roughness of $\le Ra\ 0.8 \mu m$ and a flatness deviation under $0.01\text{ mm}$. When securing the four high-tensile mounting bolts, use a calibrated torque wrench in a cross-diagonal sequence over three progressive stages to reach official values ($8.9 \text{ Nm}$ for NG6, $15.5 \text{ Nm}$ for NG10). Uneven bolt torque can twist the valve block, causing the poppet core to drag or slow its switching speed.

• Maintain Strict Fluid Filtration; Protect Internal Casing Seats from Hard Contaminants: Because this valve utilizes a metal-to-metal interference seat, hard particulate contaminants or metallic shavings suspended in the oil can degrade performance. If these particles are trapped during high-speed closure, they can pit or scratch the steel ball and seat, permanently compromising the valve’s zero-leakage capability. Keep system filtration locked below $\le 10 \mu m$ and monitor NAS fluid cleanliness classes regularly.

• Prohibit Solenoid Coil Energization when Detached from the Armature Tube: The high-power industrial solenoid coil relies on the internal steel armature tube and the surrounding valve body structure for heat dissipation. If a technician removes the coil from the valve stem during field maintenance but leaves it connected to power, the missing internal magnetic core will cause an inductive current spike. Without adequate heat dissipation, the coil will overheat and burn out within minutes.