A4VSO250DFR/30L-PPB25N00 Rexroth piston pump imported from Germany

Model Breakdown:​ A4VSO = open-circuit swash-plate variable pump · 250 = 250 mL/rev · DFR​ = pressure + flow control (pilot pressure ports X & Y) · /30 = Series 30 · L​ = CCW rotation · P​ = NBR seal · P​ = keyed shaft · B​ = 4-bolt ISO flange · 25​ = SAE port pattern size 25 (3000 psi) · N00​ = no through-drive.

DFR vs DFR1:​ DFR has pilot oil connection for pressure limiting; DFR1 additionally has a fixed orifice in X-port. Your unit is DFR (standard).

Frequently Asked Questions (FAQ)

Q1: What does "DFR" control mean on this pump?

DFR = Druck-Fluss-Regelung (Pressure + Flow Control). The pump has a pressure limiter (like DR) plus a flow/pilot-pressure input that allows remote or load-sensing control of the swash plate angle via pilot pressure at port X. It's commonly used in systems where a remote signal sets the flow setpoint while capping max pressure.

Q2: Is "L" rotation (counter-clockwise) standard?

No — R (clockwise, viewed from shaft end) is the most common industrial standard. "L" means CCW rotation — verify your motor/coupling rotation direction before installation. Shaft end view: if motor spins CW looking at pump shaft, you need "R", not "L".

Q3: Can this pump be used in closed-circuit (hydrostatic transmission)?

No. A4VSO is designed exclusively for open-circuit​ systems. For closed-circuit use Rexroth A4VG / A6VM / A11VLO series.

Q4: What are the PPB25N00 mounting / port details?

• Shaft:​ Parallel keyed (DIN 6885), splined not normally on "P" code.

• Flange:​ ISO 3019-2 / SAE J744 4-bolt (Form B).

• Ports:​ SAE flange ports — Pressure port SAE 3000 psi (size 25 = 1″), Suction port SAE 1500 psi (typically larger, check drawing). "25" in the code refers to the pressure port SAE size 25 pattern.

• Through-drive:​ None (N00).

Q5: How to plumb the case drain?

The case (housing) drain must​ be connected to tank with an unrestricted line, routed above the tank oil level​ (or use a standpipe ≤2–4 bar backpressure). Never block it. Case drain carries internal leakage — typical 2–5% of pump flow.

Q6: What is the minimum inlet / suction condition?

Maintain ≥0.8 bar absolute at the pump inlet (S-port) under all conditions. Use short, large-diameter suction line, <1500 mm preferable. Avoid suction strainers with >Δp 0.2 bar. Pre-fill or bleed the case before first start.

Q7: Start-up & commissioning tips?

• Fill housing and suction line with clean oil before first start.

• Set DFR pressure spring to minimum during initial run — ramp up slowly.

• Check rotation direction matches "L" marking on nameplate.

• Verify case drain flows to tank and is warm within minutes of operation.

• Set system relief / pressure limiter 10–15% above working pressure.

Q8: What is the difference between A4VSO and A10VSO?

A4VSO is the industrial high-power​ series (up to 1000 mL/rev, 350/400 bar, through-drive capable, multiple control options). A10VSO is the compact industrial/mobile​ series (max ~140 mL/rev, 280/350 bar). Your A4VSO250 is the large-frame industrial pump for presses, metallurgy, large power packs — not interchangeable with A10VSO.

Q9: Can I add a through-drive pump later?

This unit is N00 (no through-drive). To add a tandem gear/axial pump you would need the "K…" through-drive version (e.g., N… or K… codes). This specific P/N cannot accept a rear-mounted auxiliary pump.