Z2FS22-3X/S Rexroth Twin Throttle Check Valve 350 Bar

Product Overview

The Z2FS22-3X/S is a Bosch Rexroth Z2FS Series Twin Throttle Check Valve designed for hydraulic flow limitation in industrial actuator circuits. The Z2FS uses two integrated throttle-check elements so that flow can be restricted in one direction while return flow is permitted through the check function.

Bosch Rexroth identifies the product family as a twin throttle check valve in sandwich plate design. The valve can be used for actuator main-flow limitation as well as pilot-flow limitation.

The exact Z2FS22-3X/S configuration is associated with material number R971L20012 and is specified as Size 25, with 350 bar maximum operating pressure and 360 L/min maximum flow.

For replacement applications, the standardized sandwich mounting concept provides a strong basis for direct interchangeability, provided the complete ordering code, mounting interface, throttling direction and sealing configuration are verified. Replacement units can additionally undergo 100% simulated working-condition testing to verify flow regulation, leakage performance and operating stability.

Technical Specifications

Z2FS22-3X/S

• Manufacturer: Bosch Rexroth
• Series: Z2FS
• Valve Type: Twin Throttle Check Valve
• Full Model: Z2FS22-3X/S
• Material Number: R971L20012
• Nominal Size: Size 25
• Component Series: 3X
• Mounting: Sandwich Plate
• Actuation: Mechanical
• Maximum Operating Pressure: 350 bar
• Maximum Flow: 360 L/min
• Function: Flow limitation for one or two actuator ports
• Throttling Configuration: Supply Throttling, code S
• Displacement: Not applicable
• Rated Speed: Not applicable
• Peak Pressure: No separate higher peak-pressure value identified; 350 bar is the stated maximum operating pressure.

Z2FS16-8-31/S2

This configuration corresponds to R900457256 and is commonly represented in the newer 3X coding as Z2FS16-8-3X/S2.

• Nominal Size: Size 16
• Component Series: 3X
• Maximum Operating Pressure: 350 bar
• Maximum Flow: 250 L/min
• Mounting Standard: ISO 4401-07-07-0-05
• Actuation: Mechanical
• Adjustment: Spindle with internal hexagon
• Throttling: Discharge Throttling
• Seal: NBR
• Weight: Approximately 4.46 kg.

Z2FS10-20B

The Z2FS10-20B belongs to an older Z2FS coding system. Available legacy technical records specify:

• Nominal Size: Size 10
• Maximum Operating Pressure: 315 bar
• Maximum Flow: 160 L/min
• Valve Type: Double / Twin Throttle Check Valve

However, the currently available Bosch Rexroth official selector uses the Z2FS10-3X/ coding system rather than the legacy Z2FS10-20B code. Therefore, these legacy figures should not be automatically transferred to every modern Z2FS10 configuration.

Key Technical Advantages

1. Integrated twin throttle-check architecture

Two throttle-check elements are integrated into one valve body, providing controlled metering in one direction and low-resistance return flow in the opposite direction. This combines flow restriction and check functionality in a compact hydraulic component.

2. Main-flow and pilot-flow limitation

The Z2FS can be installed in the main actuator circuit for speed control or in pilot circuits to influence the switching time of pilot-operated hydraulic valves.

3. Supply or discharge throttling

The product family supports both supply throttling and discharge throttling, identified by the corresponding S and S2 configurations. This allows engineers to match the valve configuration to actuator load characteristics.

4. Standard sandwich-plate construction

The sandwich-mounted architecture allows integration directly into modular valve stacks, reducing the need for separate external piping and simplifying maintenance. Bosch Rexroth highlights the sandwich configuration as a fundamental feature of the Z2FS design.

5. High-flow industrial capability

The Z2FS22 configuration reaches 350 bar and 360 L/min, while the Z2FS16 configuration reaches 350 bar and 250 L/min, making the family suitable for medium- and large-flow industrial hydraulic circuits.

6. Mechanical adjustment

The Z2FS does not require an electrical solenoid or electronic amplifier for basic flow setting. Mechanical adjustment makes it suitable for applications where a fixed, manually commissioned flow setting is preferred.

7. Replacement-friendly standardized design

ISO-based sandwich mounting and standardized Z2FS type coding support maintenance and replacement applications in existing Bosch Rexroth hydraulic systems.

Application Areas

Typical applications include:

• Hydraulic Power Units
• Hydraulic Presses
• Injection Molding Machinery
• Metal Forming Equipment
• Machine Tools
• Hydraulic Clamping Systems
• Hydraulic Cylinder Speed Control
• Large Hydraulic Actuator Systems
• Pilot-Operated Directional Valve Circuits
• Industrial Hydraulic Manifolds

The Z2FS is particularly suitable where actuator speed, main flow or pilot flow must be reliably restricted.

Expert Maintenance Tips

Verify the complete ordering code

Do not identify a replacement only by Z2FS10, Z2FS16 or Z2FS22. Verify nominal size, component series, adjustment type, throttling direction, seal material and optional pilot-oil configuration.

The current Bosch Rexroth Z2FS10 selector confirms that several adjustment and sealing configurations are available within the same nominal size.

Confirm the throttling strategy

Before replacement, determine whether the original machine uses supply throttling or discharge throttling. This distinction can significantly affect cylinder stability, especially under overrunning or inertial loads.

Secure the adjustment setting

After commissioning, secure the spindle or adjustment mechanism to prevent vibration-induced changes in actuator speed.

Inspect the sandwich interface

Check the mounting surface, O-rings, fastening bolts and orientation before commissioning. Contamination or damaged seals can result in internal or external leakage.

Maintain hydraulic cleanliness

The throttle and check elements contain precision moving components. Contaminated oil can cause unstable flow control, poor check-valve sealing or actuator speed fluctuations.

Treat Z2FS10-20B as a legacy code

Do not automatically substitute a current Z2FS10-3X/ configuration for Z2FS10-20B without checking the original machine documentation and hydraulic circuit. The current Bosch Rexroth selector uses the newer 3X coding architecture.