Rexroth R900927159 Relief Valve | Overflow & Flow Control Valve | DBW Series Replacement

The R900927159, manufactured by Chengyuan Hydraulic, is a high-performance pilot-operated relief valve designed to meet the rigorous standards of the Bosch Rexroth DB/DBW series. Functioning as a critical safety and pressure control component, this valve prevents hydraulic system overloads by accurately discharging excess flow when the preset pressure is reached. Chengyuan guarantees 100% Drop-in Interchangeability with original Rexroth R900927159 valves, matching all mounting interfaces and DIN 24340 porting patterns. Every unit is subjected to 100% simulation load testing on our digital benches to ensure zero-leak performance and rapid response under high-pressure cycles.

Technical Specifications 

• Compatible Brand: Bosch Rexroth

• Part Number: R900927159

• Valve Type: Pilot Operated Relief Valve

• Nominal Size: Size 10 (Standard for this series)

• Max. Operating Pressure: 315 Bar / 350 Bar (31.5-35 MPa)

• Max. Flow Rate: Approx. 250 – 400 L/min (Depending on frame size)

• Pressure Adjustment Range: Up to 315 Bar

• Control Method: Manual adjustment knob (with optional solenoid unloading)

• Sealing Material: Premium NBR / FKM (Optional)

Key Technical Advantages:

• Superior Static & Dynamic Stability: The pilot-operated design eliminates the pressure oscillation common in direct-acting valves during high-flow conditions. It maintains a stable pressure ceiling even during extreme flow fluctuations, protecting the pump units.

• Low Hysteresis Precision Spool: The internal pilot spool is precision-ground and paired with fatigue-tested springs. This ensures high repeatability for opening and closing points with minimal hysteresis, enhancing overall system responsiveness.

• Anti-Contamination Flow Paths: Internal geometries are optimized via fluid dynamics to reduce heat generation and noise during overflow. The design allows for better particle passage, preventing pilot orifice clogging that could cause pressure loss.

• Hardened Valve Seats: Seats are constructed from high-strength alloy steel and vacuum-quenched. The extreme hardness and impact resistance ensure a tight seal even after frequent relief operations, preventing internal leakage.

Application Areas:

• Industrial Presses: Pressure safety limiting for injection molding and hydraulic pressing machines.

• Hydraulic Power Units (HPU): Primary relief valve for regulating main system pressure in fixed or variable displacement pump systems.

• Mobile Machinery: Pressure control in auxiliary hydraulic circuits for excavators, cranes, and loaders.

• Metallurgy Equipment: Overload protection for large hydraulic actuators in steel production lines.

Expert Maintenance Tips:

• Pressure Setting Protocol: Never set the relief pressure higher than 1.1 times the pump’s rated pressure. When adjusting, monitor the pressure gauge and rotate the handle slowly to avoid sudden hydraulic shocks.

• Pilot Orifice Cleaning: If the system fails to build pressure or respond to adjustments, the pilot orifice may be clogged. Disassemble the pilot section and clean carefully. Avoid using wire to clear holes to prevent scratching precision surfaces.

• Oil Cleanliness Standard: Maintain hydraulic oil cleanliness at NAS Class 8 or better. Installing a high-precision pressure filter upstream of this valve is recommended to prevent spool jamming from the source.