When hydraulic systems need reliable load holding and leak-free isolation, engineers often turn to the Check Valve Sandwich Plate Z2S 6 from Bosch Rexroth. This pilot-operated valve has been a trusted component in industrial hydraulics since 2013, offering straightforward installation and dependable performance across various applications.
The Z2S 6 check valve sandwich plate is designed to fit between hydraulic components in a vertical stack, saving space while providing essential flow control. It allows free flow in one direction while blocking reverse flow until a pilot pressure signal releases it. This simple yet effective mechanism makes the check valve sandwich plate Z2S 6 particularly valuable in systems where loads must remain stationary during idle periods.
Understanding the Z2S 6 Design
The check valve sandwich plate Z2S 6 follows the NG6 size standard, also known as Size 6 in hydraulic terminology. This standardization means it matches the mounting pattern specified in DIN 24340, ISO 4401-03-02-0-05, and NFPA T3.5.1 R2-2002 D03. Engineers appreciate this compatibility because it allows the valve to integrate smoothly with existing hydraulic systems worldwide.
The basic operation of the Z2S 6 check valve sandwich plate involves a spring-loaded piston and spool mechanism. Fluid flows freely from the equipment side (ports A1 or B1) to the manifold side (ports A2 or B2). When pressure tries to reverse direction, the valve closes tightly with zero leakage. Opening the blocked valve requires pilot pressure at designated control ports, which mechanically shifts the internal components to allow reverse flow.
Bosch Rexroth offers the check valve sandwich plate Z2S 6 in several configurations. The standard version blocks both A and B channels. Single-channel variants (Z2S 6 A or Z2S 6 B) isolate only one port, giving designers more flexibility in circuit design. The valve body measures approximately 11mm thick in standard configurations, though special versions with pre-opening features extend to 21.5mm.
Technical Specifications That Matter
The check valve sandwich plate Z2S 6 handles pressures up to 315 bar (4,568 psi) when used with mineral oil-based hydraulic fluids. Flow capacity reaches 60 liters per minute, which suits most industrial applications. These numbers represent tested performance with HLP 46 oil at 40°C, the standard reference condition for hydraulic components.
Cracking pressure is the force needed to open the valve for free flow. The Z2S 6 check valve sandwich plate comes in three cracking pressure options: 1.5 bar, 3 bar, or 6 bar. Lower cracking pressures provide more sensitive response, while higher settings offer firmer closure against system vibrations. The choice depends on your specific circuit requirements and the nature of your hydraulic loads.
Temperature tolerance varies with seal material. Standard NBR seals work from -30°C to +80°C, covering most industrial environments. For applications involving high temperatures or aggressive fluids, FKM seals extend the lower limit to -20°C while maintaining the same upper boundary. The check valve sandwich plate Z2S 6 also accommodates biodegradable hydraulic fluids (HETG and HEES types) and fire-resistant fluids, though water-based HFC fluids require pressure limitation to 210 bar.
Fluid viscosity can range from 2.8 to 500 mm²/s without affecting valve operation. This wide range means the check valve sandwich plate Z2S 6 functions properly whether your hydraulic oil is thin from heat or thick from cold startup conditions. The valve maintains its sealing integrity across this entire viscosity spectrum.
Where the Z2S 6 Check Valve Sandwich Plate Excels
Press machines rely heavily on the check valve sandwich plate Z2S 6 to prevent load drift. When a press holds material between cycles, any cylinder movement would ruin the workpiece. The zero-leakage blocking of the Z2S 6 keeps the ram exactly where the operator positions it, even during extended pauses. This reliability eliminates the need for constant pump pressure to maintain position, saving energy and reducing heat generation.
Lifting equipment presents similar challenges. A hydraulic lift supporting a load cannot tolerate gradual descent due to internal leakage. The check valve sandwich plate Z2S 6 isolates the lift cylinder completely, ensuring that loads stay elevated until the operator deliberately lowers them. This safety feature is particularly important in applications where people work beneath elevated platforms or vehicles.
Automated production lines benefit from the compact design of the Z2S 6 check valve sandwich plate. Modern automation demands many actuators operating in coordinated sequences, often within tight spaces. The sandwich plate design allows multiple valves to stack vertically on a single manifold, minimizing the footprint while maintaining full functionality for each circuit. This space efficiency translates directly into more compact machine designs.
The pre-opening variants of the check valve sandwich plate Z2S 6 address a specific problem in high-cycle applications. When a blocked valve suddenly releases under full system pressure, the rapid flow change creates hydraulic shock. The SO55 and SO150 versions incorporate pre-opening circuits that gradually reduce trapped pressure before full release. This gentle transition reduces noise, minimizes component wear, and extends system life in applications with frequent start-stop cycles.
Installation Considerations
Mounting the check valve sandwich plate Z2S 6 requires attention to surface flatness. The mating surfaces on your manifold or base plate must achieve a roughness of Ra 0.01/100 mm or better. This smooth finish ensures proper sealing without overtightening the mounting bolts. Most manufacturers specify M5 socket head cap screws (ISO 4762) or 10-24 UNC threads for North American applications.
Bolt torque depends on the number of components in your stack. A simple two-layer assembly uses lower torque than a complex manifold with multiple valves. Bosch Rexroth provides torque tables in their documentation, but typical values for M5 screws range from 5 to 7 Nm. The key is uniform tightening in a cross pattern to distribute clamping force evenly across the sealing surfaces.
The check valve sandwich plate Z2S 6 can be installed in any orientation, though vertical stacking is most common. Horizontal or angled mounting works fine if your machine layout requires it. Just ensure that mounting surfaces remain properly supported and that porting connections align with your hydraulic lines. The valve's internal design does not depend on gravity, so performance remains consistent regardless of position.
Hydraulic circuit designers should account for the pilot control requirements when planning installations. Standard Z2S 6 versions use internal pilot pressure from the blocked port itself. Special variants like the SO40 add external G1/4 control ports for independent pilot signals. The SO60 version drains pilot pressure to the tank port, which helps in circuits where blocked pressure should not influence other components. Understanding these control options helps you select the right check valve sandwich plate Z2S 6 variant for your specific application.
Maintenance and Troubleshooting
The check valve sandwich plate Z2S 6 requires minimal maintenance under normal operating conditions. Regular inspection every 12 to 24 months catches potential issues before they cause system failures. Check for external leakage around the mounting surfaces and verify that pilot control lines remain unobstructed. Contamination is the primary enemy of any hydraulic valve, so maintaining proper fluid cleanliness according to ISO 4406 class 20/18/15 protects the Z2S 6 check valve sandwich plate from premature wear.
If your system experiences excessive switching shock when the valve releases, consider upgrading to a pre-opening version. The SO55 variant provides moderate cushioning, while the SO150 offers more gradual pressure reduction. This modification often eliminates noise complaints and reduces stress on connected components without requiring major circuit redesign.
Leakage past a check valve sandwich plate Z2S 6 usually indicates contamination damage to the sealing surfaces. Solid particles can embed in the soft seal material or scratch the metal seating surfaces. Disassembly and cleaning sometimes restores function, but replacement is often more economical given the relatively low cost of these components. When replacing seals, always use genuine Bosch Rexroth parts specified for your valve's model number to ensure proper fit and material compatibility.
Pilot control failure presents as an inability to release the blocked flow. This problem typically stems from debris blocking the small pilot passages or from incorrect pilot pressure supply. The check valve sandwich plate Z2S 6 requires adequate pilot pressure to overcome both the cracking pressure and any trapped load pressure. Verify that your pilot source delivers sufficient flow and pressure for reliable operation. In systems with long pilot lines, consider adding a pilot accumulator to provide quick response.
Purchasing the Check Valve Sandwich Plate Z2S 6
Pricing for the check valve sandwich plate Z2S 6 varies with configuration and purchase source. Standard models like the R900347495 typically range from $150 to $300 USD. Pre-opening versions and special seal materials add to the base cost. Authorized distributors offer genuine Bosch Rexroth components with factory warranties and technical support.
Bosch Rexroth's official store provides the most comprehensive selection and direct manufacturer support. Their website includes detailed specifications, CAD models, and compatibility information for the Z2S 6 check valve sandwich plate. Engineers appreciate the technical documentation available for download, which includes pressure-flow curves and dimensional drawings.
Regional distributors often maintain local inventory for faster delivery. [BuyRexroth.com](http://buyrexroth.com/) serves online buyers with competitive pricing and quick shipping on common configurations. Leader Hydraulics focuses on Asian markets with local stock and support. PHA-Auto in Thailand provides regional expertise for Southeast Asian installations. These distributors understand the check valve sandwich plate Z2S 6 thoroughly and can recommend the right variant for your specific application.
Bulk purchases qualify for volume discounts at most suppliers. If your production requires multiple Z2S 6 check valve sandwich plate units, requesting a quote for your total requirement often reveals better pricing than ordering individually. Some distributors also bundle the valve with mounting hardware and seals at reduced package prices.
Generic alternatives exist at lower price points, sometimes appearing under $100. These clone products may physically fit the mounting pattern, but material quality and manufacturing tolerances often fall short of Rexroth standards. For non-critical applications or temporary testing, lower-cost alternatives might suffice. However, systems requiring reliable long-term performance justify the investment in genuine check valve sandwich plate Z2S 6 components.
Ordering Codes Explained
Understanding Bosch Rexroth's ordering code helps you specify exactly the check valve sandwich plate Z2S 6 variant you need. The format follows this pattern: Z2S 6 [blocking configuration] [cracking pressure] 6X [surface treatment] [seal material] [positioning features] [special options].
The blocking configuration determines which ports the valve isolates. A dash with no letter means both A and B channels block. The letter A means only the A channel blocks while B flows freely. The letter B reverses this arrangement. This flexibility lets circuit designers isolate specific actuator ports without affecting others in the same manifold.
Cracking pressure codes are simple numbers: 1 for 1.5 bar, 2 for 3 bar, and 3 for 6 bar. This selection affects how much pressure builds before free flow begins. The 6X designation indicates the size 6 component series, which remains constant for all standard check valve sandwich plate Z2S 6 models.
Surface treatment appears as J50 for passivated stainless surfaces that resist corrosion in harsh environments. Standard versions omit this code. Seal material shows as V for FKM when needed; otherwise, standard NBR seals are understood. Positioning options include /60 for locating holes and /62 for holes plus dowel pins, though pins must be ordered separately using part number R900005694.
Special function codes indicate advanced features. SO40 adds external G1/4 control ports for independent pilot signals. SO55 and SO150 enable pre-opening circuits with different timing characteristics. SO60 routes pilot drain to the tank port. These special variants of the check valve sandwich plate Z2S 6 address specific circuit requirements that standard models cannot accommodate.
Comparing Alternatives
Other manufacturers produce hydraulic check valves that compete with the Z2S 6 check valve sandwich plate. Parker's D1VW series offers similar functionality with cartridge-style construction. These valves handle slightly higher pressures (350 bar) and flows (80 l/min), which matters in heavy-duty applications. However, the cartridge design requires different manifold preparation compared to the sandwich plate format that makes the Z2S 6 so versatile.
Eaton provides PVQ check valves that match Z2S 6 capabilities at somewhat lower cost. Pressure ratings reach 345 bar with flows around 50 l/min. For applications where the slightly reduced flow capacity suffices, Eaton valves present a viable alternative. The check valve sandwich plate Z2S 6 maintains advantages in availability and documentation, particularly for international projects where Rexroth's global presence simplifies sourcing and support.
Generic clone valves tempt buyers with prices below $100, sometimes reaching as low as $50. These products physically fit NG6 mounting patterns, making them mechanically compatible with systems designed for the Z2S 6 check valve sandwich plate. However, material quality and precision manufacturing directly affect reliability and lifespan. Clone valves often exhibit higher internal leakage, inconsistent cracking pressures, and shorter service life. They serve adequately for testing, prototyping, or non-critical backup applications, but production systems benefit from genuine components.
The check valve sandwich plate Z2S 6 stands out in integrated Bosch Rexroth systems where other valves, pumps, and controls come from the same manufacturer. Component compatibility is assured, documentation is comprehensive, and technical support understands the complete system. This ecosystem advantage often outweighs small price differences when building professional hydraulic installations.
Real-World Performance
Industrial users consistently report reliable operation from the check valve sandwich plate Z2S 6 across diverse applications. CNC machine builders integrate these valves into hydraulic circuits controlling tool clamping and part positioning. The zero-drift characteristic ensures that machining accuracy is not compromised during cycle pauses. Machine shops running 24-hour operations particularly value the consistent performance that requires minimal intervention.
Construction equipment manufacturers specify Z2S 6 variants in stabilizer circuits and boom positioning systems. Mobile hydraulics face challenging conditions including vibration, temperature extremes, and contamination exposure. The check valve sandwich plate Z2S 6 meets these demands while maintaining the small size essential in space-constrained mobile applications. Fire-resistant fluid compatibility extends its use into underground mining equipment where safety regulations mandate HFC hydraulic fluids.
Automated assembly lines demonstrate the value of pre-opening Z2S 6 variants. Systems cycling multiple times per minute generate significant hydraulic shock during each transition. Engineers report noticeable noise reduction and smoother operation after retrofitting standard check valve sandwich plate Z2S 6 units with SO55 pre-opening versions. This upgrade often extends the service life of connected components by reducing stress spikes throughout the circuit.
Hydraulic power units in industrial plants use Z2S 6 valves to isolate accumulator banks and create independent pressure zones. The compact sandwich design allows complex manifold assemblies that would be impractical with larger, less standardized components. Maintenance technicians appreciate the modular nature of these installations, where individual check valve sandwich plate Z2S 6 units can be replaced without disturbing adjacent components.
Technical Resources and Support
Bosch Rexroth provides extensive documentation for the check valve sandwich plate Z2S 6 through their online portal. The primary reference document, RE 21548, contains complete specifications, performance curves, and dimensional drawings. This PDF remains freely available for download, ensuring that engineers worldwide can access accurate information when designing hydraulic systems.
CAD models in multiple formats support digital design workflows. STEP and IGES files import directly into common mechanical design software, allowing proper clearance checks and hydraulic line routing. These models reflect the exact dimensions of the check valve sandwich plate Z2S 6, eliminating guesswork and reducing design errors that might appear during physical installation.
Technical support from Bosch Rexroth helps resolve specific application questions. Their engineers can recommend the optimal Z2S 6 variant for unusual operating conditions or help troubleshoot performance issues in existing installations. Regional offices maintain familiarity with local fluid standards and environmental requirements, ensuring that advice accounts for regional variations in hydraulic practice.
Distributor technical staff often provide front-line support for the check valve sandwich plate Z2S 6. Many distributors employ experienced hydraulic technicians who understand both the product and common application challenges. This local expertise can be particularly valuable during initial system commissioning or when diagnosing unexpected behavior in complex circuits.
Online communities and forums discuss practical experiences with hydraulic components including the Z2S 6. These conversations reveal real-world solutions to common problems and sometimes highlight undocumented tips from experienced users. While informal sources should not replace official documentation, they provide useful context about how the check valve sandwich plate Z2S 6 performs across different industries and applications.
Making the Right Choice
Selecting the appropriate check valve sandwich plate Z2S 6 variant starts with understanding your system requirements. Calculate the maximum pressure your circuit will experience and verify that it stays within the 315 bar rating for mineral oil or 210 bar for water-based fluids. Measure expected flow rates to confirm they remain below 60 l/min. These basic checks ensure the valve can handle your operating conditions without performance degradation.
Consider whether your application benefits from pre-opening features. Systems with frequent cycling, sensitive loads, or noise concerns often justify the modest additional cost of SO55 or SO150 variants. The smoother transitions they provide reduce stress on the entire hydraulic system, potentially preventing failures in other components. For applications that hold loads for extended periods with infrequent releases, standard check valve sandwich plate Z2S 6 models work perfectly well.
Seal material selection depends on your hydraulic fluid and temperature environment. Standard NBR seals accommodate conventional mineral oils and most biodegradable fluids within the -30°C to +80°C range. If your application involves higher temperatures, aggressive fluids, or frequent exposure to cold environments, FKM seals provide better durability. The check valve sandwich plate Z2S 6 with V designation includes these upgraded seals.
Budget considerations balance initial cost against long-term reliability. Genuine Bosch Rexroth components cost more upfront but deliver predictable performance over many years. Generic alternatives save money initially but may require more frequent replacement. For critical applications where unexpected failures cause production losses, the proven reliability of the Z2S 6 check valve sandwich plate justifies its price. For less critical backup circuits or temporary installations, lower-cost alternatives might make economic sense.
Conclusion
The check valve sandwich plate Z2S 6 represents a mature, well-proven solution for hydraulic load holding and flow control. Its standardized design, reliable operation, and comprehensive configuration options make it suitable for diverse industrial applications. Whether you need simple leak-free blocking or sophisticated pre-opening control, a Z2S 6 variant exists to match your requirements.
Understanding the technical specifications helps you select the right model and avoid compatibility issues. Proper installation ensures long service life and trouble-free operation. Regular maintenance catches problems early, while access to genuine parts and technical support protects your investment. The check valve sandwich plate Z2S 6 continues to serve hydraulic systems worldwide, proving that straightforward engineering combined with quality manufacturing creates components that simply work.
