A4VSO250DRG/30L-PPB25N00 German Rexroth piston pump imported with original packaging

DRG is pressure control with remote pressure setting. Like DR (direct-set constant pressure), the pump limits system pressure by reducing displacement when pressure reaches the setpoint. The difference: DRG's pressure setpoint is not set by an onboard spring knob but is determined by an externally connected pilot relief valve (on port XD/X).

DR has an onboard adjusting screw for direct setting; DRG is used when you want to adjust the pump's pressure setpoint remotely (e.g. from a cabinet or PLC-controlled pilot valve).

Connect a pilot relief valve (DB …-5X/… type recommended) between the DRG's XD port and tank. The pilot valve's cracking pressure determines the base setpoint. The XD port must never be blocked - blocking XD will prevent the DRG from functioning and the pump may stay at full displacement. A small amount of pilot oil (≈1.5-3 L/min) flows through the DRG when active.

Yes. The PPB code indicates through‑drive capability. You can flange-mount another A4VSO pump (same or smaller size) on the rear to form a tandem/combo pump. N00 = no auxiliary gear pump pre-fitted, through-drive shaft is present.

• Case Drain: Plumb directly to tank, backpressure ≤ 1.5-2 bar. Never tee into main return.
• Suction Line: Short & large-diameter; absolute inlet pressure ≥ 0.8 bar. Use 100 µm suction strainer.
• Rotation Check: "L" = counter‑clockwise from shaft end - verify prime mover direction before coupling.
• Bleed: Fill case and suction with oil and vent before first start-up.
• XD Pilot Line: Ensure pilot relief valve is properly sized and connected; confirm pilot supply pressure is adequate.

Yes, strongly recommended. DRG provides pressure limiting under normal conditions but has finite response time. A system safety relief valve (e.g. DB type, set slightly above max DRG setpoint + margin) protects against pressure spikes from thermal expansion, control lag, or pilot valve failure.

Maintain ISO 4406 18/16/13 (NAS 1638 Class 8 -9) minimum using a return-line filter β₁₀ ≥ 200. Contamination is the primary cause of premature wear in A4VSO pumps.

B25 = SAE flange side ports with pressure port (B) and tank port (S) 90° apart, plus a second pressure port (B1) on the opposite side of B, normally plugged with a SAE flange blank. This allows cascade loading or superimposing signals in multi-pump systems.