Product Overview
DZ10-1-30B/210, DZ10-1-30B/210XY, DZ20-1-30B/210, and DZ30-1-30B/210 are representative models from Bosch Rexroth’s DZ series of pilot-operated pressure sequence valves, covering nominal sizes NG10, NG20, and NG30 with subplate mounting conforming to DIN 24340 standards.
The DZ series pilot-operated sequence valves are used for hydraulic systems requiring pressure-dependent sequential actuation. The DZ type valve consists of a pilot valve, a main valve with insert-type main spool, and an optional check valve. The operating principle is: pressure oil from chamber A acts via channels and damping orifices on the pilot valve control piston, while also acting on the upper chamber of the main spool. When chamber A pressure exceeds the spring setting, the control piston moves, allowing oil from the main spool upper chamber to flow through damping orifices and control edges to chamber B—creating a pressure differential across the main spool that opens the connection from chamber A to chamber B. The spring maintains constant cracking pressure.
DZ10-1-30B/210 is the standard pilot-operated sequence valve configuration with internal pilot supply and internal drain.
DZ10-1-30B/210XY features XY-type configuration—pilot oil is supplied externally via port X, and pilot spool leakage oil is directed to tank via a depressurized connection at port Y. The XY-type configuration effectively eliminates back pressure interference with the set pressure, making it ideal for high-precision control applications.
The 30B series designates the specific component series (series 30–39) with unchanged installation and connection dimensions.
As a direct replacement solution for the Bosch Rexroth DZ series, this product strictly complies with Rexroth technical standards and offers complete interchangeability—direct drop-in replacement without any modification to mounting dimensions or piping connections. Every unit undergoes 100% simulated duty cycle testing prior to shipment, ensuring performance reliability and long-term operational stability under actual working conditions.
Technical Specifications
DZ10-1-30B/210
Model: DZ10-1-30B/210
Series: DZ (Pilot-operated Pressure Sequence Valve)
Brand: Bosch Rexroth
Nominal Size: 10 (NG10)
Component Series: 30B (series 30–39)
Mounting Type: Subplate Mounting
Porting Pattern Standard: DIN 24340
Maximum Operating Pressure: 315 bar (31.5 MPa)
Pressure Setting Range: Up to 210 bar
Maximum Flow Rate: 80 L/min
Control Type: Pilot-operated, internal pilot supply, internal drain (standard)
Spool Construction: Main valve – poppet type; Pilot valve – spool type
Adjustment Elements: Rotary knob / Setscrew with protective cap / Lockable rotary knob with scale / Rotary knob with scale
Optional Function: Check valve available
Seal Material: NBR
Hydraulic Fluid: HL, HLP mineral-oil-based hydraulic fluids
Fluid Temperature Range: -30 °C to +80 °C
Viscosity Range: 10 – 800 mm²/s
DZ10-1-30B/210XY
Model: DZ10-1-30B/210XY
Series: DZ (Pilot-operated Pressure Sequence Valve)
Brand: Bosch Rexroth
Nominal Size: 10 (NG10)
Component Series: 30B (series 30–39)
Mounting Type: Subplate Mounting
Porting Pattern Standard: DIN 24340
Maximum Operating Pressure: 315 bar
Pressure Setting Range: Up to 210 bar
Maximum Flow Rate: 80 L/min
Control Type: Pilot-operated, external pilot supply & external drain (XY-type) —pilot oil supplied via external port X, leakage oil independently returned to tank via port Y
Spool Construction: Main valve – poppet type; Pilot valve – spool type
Adjustment Elements: Rotary knob / Setscrew with protective cap / Lockable rotary knob with scale / Rotary knob with scale
Optional Function: Check valve available
Seal Material: NBR
Hydraulic Fluid: HL, HLP mineral-oil-based hydraulic fluids
Fluid Temperature Range: -30 °C to +80 °C
Viscosity Range: 10 – 800 mm²/s
DZ20-1-30B/210
Model: DZ20-1-30B/210
Series: DZ (Pilot-operated Pressure Sequence Valve)
Brand: Bosch Rexroth
Nominal Size: 20 (NG20)
Component Series: 30B (series 30–39)
Mounting Type: Subplate Mounting
Maximum Operating Pressure: 315 bar
Pressure Setting Range: Up to 210 bar
Maximum Flow Rate: 400 L/min
Control Type: Pilot-operated
Spool Construction: Main valve – poppet type; Pilot valve – spool type
DZ30-1-30B/210
Model: DZ30-1-30B/210
Series: DZ (Pilot-operated Pressure Sequence Valve)
Brand: Bosch Rexroth
Nominal Size: 30 (NG30)
Component Series: 30B (series 30–39)
Mounting Type: Subplate Mounting
Maximum Operating Pressure: 315 bar
Pressure Setting Range: Up to 210 bar
Maximum Flow Rate: 600 L/min
Control Type: Pilot-operated
Spool Construction: Main valve – poppet type; Pilot valve – spool type
Key Technical Advantages
1. Precision Combination of Poppet-Type Main Spool & Spool-Type Pilot Valve
The DZ series features a poppet-type main valve and a spool-type pilot valve. The poppet-type main valve provides excellent sealing performance and extremely low internal leakage; the spool-type pilot valve delivers precise pressure control and fast response. Their precision combination achieves the perfect balance of high-accuracy pressure control and long-term sealing reliability.
2. Four Control Oil Configurations – Flexible System Adaptation
The DZ series offers four control oil configurations:
Internal Supply & Internal Drain (Standard) : Pilot oil supplied from chamber A internally; leakage oil drained internally to chamber B—suitable for standard sequence control applications
External Supply & Internal Drain (X-type) : Pilot oil supplied externally via port X—ideal when chamber A pressure is insufficient to drive the pilot valve
Internal Supply & External Drain (Y-type) : Pilot oil supplied from chamber A internally; leakage oil independently returned to tank via external port Y—eliminates back pressure interference
External Supply & External Drain (XY-type) : Pilot oil supplied externally via port X; leakage oil independently returned to tank via port Y—combines external supply with independent drain advantages
3. Multi-Function Valve – Sequence, Back Pressure, and Unloading in One
The DZ series valve can serve as a sequence valve, back pressure valve, and unloading valve. By changing the control oil supply/drain configuration and selecting different options (with or without check valve), the same valve body can perform three different hydraulic functions. This highly integrated design significantly reduces the number of valves required in the system, simplifies manifold layout, and lowers system cost.
4. Optional Check Valve – Free Return Flow
The DZ series offers an optional integrated check valve. When equipped with the check valve, oil is allowed to flow freely from chamber B back to chamber A without overcoming the sequence valve setting. This is especially important when secondary circuit pressure exceeds primary circuit pressure, effectively preventing abnormal system pressure rise.
5. Four Adjustment Elements – Versatile Operating Options
The DZ series offers four pressure adjustment types:
Rotary Knob: Intuitive and simple, ideal for frequent adjustment
Setscrew with Protective Cap: Prevents tampering, ideal for applications not requiring frequent adjustment after setting
Lockable Rotary Knob with Scale: Precise setting with locking, ideal for applications requiring repeatable precision positioning
Rotary Knob with Scale: Precise visual adjustment, ideal for working environments requiring accurate readings
6. Broad Size & Flow Coverage
The DZ series covers NG10, NG20, and NG30 nominal sizes, with flow rates ranging from 80 L/min to 600 L/min. Pressure ratings include 25 bar, 75 bar, 150 bar, 210 bar, and 315 bar. The extensive selection enables adaptation to hydraulic systems ranging from small machine tools to large metallurgical equipment.
Application Areas
Sequence Motion Control: Automatic secondary circuit switching in hydraulic systems requiring multiple actuators to operate in pressure sequence
Back Pressure Valve Applications: Establishing required back pressure in return lines
Unloading Valve Applications: System unloading upon reaching set pressure
Injection Molding Machinery: Sequential switching control for multi-stage injection pressures
Hydraulic Presses & Die-Casting: Sequential motion control for slides, ejector cylinders, and other actuators
Mobile Machinery: Sequential control and pressure switching for implement functions
Metallurgical Equipment: Sequence control and pressure switching in rolling mill hydraulic systems
Marine & Offshore: Sequence control and pressure-dependent switching in hydraulic systems
Expert Maintenance Tips
1. Mounting Surface Verification
DZ series sequence valves conform to DIN 24340 standards. Thoroughly clean the mounting surface prior to installation and inspect O-ring seals—replace after every disassembly.
2. Installation Torque
Tighten mounting bolts in diagonal sequence over multiple passes to torque values specified in Rexroth technical documentation. Torque requirements vary by nominal size—refer to the respective technical data for NG10, NG20, and NG30.
3. XY-Type (External Supply & External Drain) Port Connection Requirements
For XY-type configurations (DZ10-1-30B/210XY), pilot oil must be supplied via external port X, and pilot spool leakage oil must be independently returned to tank via port Y. Port X supply pressure must meet pilot valve requirements; the Port Y line should be independently returned to tank and must not be parallel-connected with return lines from other valves to prevent back pressure interference with the set pressure. Excessive Port Y back pressure will cause setpoint drift.
4. Pressure Setting Procedure
To adjust pressure: turn the adjustment element clockwise to increase set pressure, counterclockwise to decrease. Final calibration should be performed under actual system operating flow and temperature conditions and verified 2–3 times to ensure accuracy. Lock the lock nut (if applicable) after adjustment.
5. Hydraulic Fluid Cleanliness Control
The DZ series features精密 clearances between the spool and body, making it sensitive to fluid contamination. Maintain system fluid cleanliness at ISO 4406 16/13 (or NAS 1638 Class 8) or better, with a filter of no less than 10 μm upstream.
6. Scheduled Maintenance
Perform preventive maintenance every 2,000 operating hours or every six months:
Verify sequence actuation pressure matches the set value
For XY-type configurations, check port X supply pressure and port Y return line for abnormalities
Check for abnormal leakage or pressure drift
Inspect adjustment mechanism for smooth operation
Inspect O-ring seals for aging, hardening, or damage (replace after every disassembly)
Verify check valve (if equipped) opens and closes correctly
