A4VSO355DR/30L-PPB13N00 German Rexroth axial piston pump

💡 Code breakdown PPB13N00: P=Keyed shaft | P=NBR seal | B=ISO 4-hole flange | 13=Side port type with metric BSPP threads | N00=No thru-drive aux pump.

DR​ = Direct-operated pressure compensator — the simplest pressure control for A4VSO: turn the handwheel to set cut-off pressure; pump goes to near-zero displacement when pressure is reached, maintaining pressure with minimal flow (holding function).

Frequently Asked Questions (FAQ)

Q1: What is the difference between DR, DRG, and DFR1 controls on A4VSO pumps?

A:

• DR​ (this model): Direct-operated pressure compensator — cut-off pressure set mechanically only​ via handwheel on the pump. Simplest and most economical.

• DRG: Same as DR but adds a remote pilot pressure port (X)​ so the pressure setpoint can be shifted remotely (e.g., by solenoid valve), useful for multi-stage pressure systems.

• DFR1: Pressure + Flow (Load Sense) controller — maintains constant Δp across a downstream orifice for energy-saving flow control; more complex than DR/DRG.

  Choose DR for straightforward constant-pressure applications; DRG for remote pressure switching; DFR1 for load-sensing systems.

Q2: This model has "L" (counter-clockwise). Can I use an "R" (clockwise) version?

A: Only if your drive motor can be reversed. "L" = CCW viewed from shaft end, "R" = CW. Pump housings and port orientations are the same, but shaft rotation is not interchangeable​ unless you change motor rotation direction. Always verify motor rotation before ordering.

Q3: Does A4VSO355 require a case drain line? How to plumb it?

A: Yes, a case drain (housing leakage / L-port) line is mandatory.​ Return it directly to tank above the oil level or via a standpipe ≤ 0.5 bar backpressure. Never block it or tee it into the suction line — excessive case pressure will blow the shaft seal. Fill the case with clean hydraulic oil before first start-up.

Q4: Port code "13" vs "25" — what's the difference?

A: "13" = side ports with metric BSPP (G) threads​ (European industrial standard). "25" = SAE flange ports​ (4-bolt flanged, typical on North American or high-flow mobile units). This model uses "13" — ensure hose adaptors are G-threaded, not SAE.

Q5: Can this pump be used in closed-loop (hydrostatic transmission) circuits?

A: No.​ A4VSO is designed exclusively for open-circuit​ applications (pump → directional valve → actuator → tank). For closed-loop travel drives, use A4VG or A6VM/A2FM series with a charge pump.

Q6: Critical installation & filtration requirements?

A:

• Filtration: Maintain system cleanliness ≤ NAS 9 (≈ ISO 4406 17/15/12), 10 µm or finer return/full-flow filter — contamination is the leading cause of premature failure.

• Suction: Short, generously sized inlet line; min. inlet pressure 0.8 bar abs; 100–150 mesh suction strainer recommended.

• Alignment: Flexible coupling only — no radial/axial shaft loads​ from the motor.

• Bleeding: Vent pump housing and system high-points before initial run to prevent air-lock/cavitation damage.