A4VSO355DRG/30L-PPB25N00 Rexroth manufactures the original A4VSO355 series piston pump from Germany

💡 Code breakdown PPB25N00: P=Keyed shaft | P=NBR seal | B=ISO 4-hole flange | 25=SAE flange side ports​ (vs. "13" = metric threaded) | N00=No thru-drive aux pump.

DRG​ = DR pressure compensator with remote pilot port (X)​ — the pressure cut-off setpoint can be shifted remotely by applying pilot pressure from an external valve, while the handwheel still acts as a mechanical maximum limit stop.

Frequently Asked Questions (FAQ)

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

A:

• DR​ (this model minus G): Direct-operated pressure compensator — cut-off pressure set mechanically only via handwheel on pump.

• DRG​ (this model): Same pressure compensator plus remote pilot port X​ — an external relief or reducing valve can set/change the cut-off pressure remotely (e.g., dual-pressure staging via solenoid), while the handwheel sets the max safety limit.

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

  Choose DRG when you need remotely switchable pressure setpoints in a constant-pressure system.

Q2: This model has "L" (counter-clockwise). Can I substitute 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 identical, but rotation direction is not interchangeable​ unless you change motor rotation. 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 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 "25" vs "13" — what's the difference and what fittings do I need?

A: "13" = side ports with metric BSPP (G) threads; "25" = side ports with SAE 4-bolt flanges​ (Pressure port typically SAE Code 61 / 6000 psi, Suction SAE Code 62 / 3000 psi). This model uses "25" — you need SAE split-flange halves and O-rings, not threaded adaptors.

Q5: How is the remote pressure setpoint (DRG) applied?

A: Connect a remote pilot relief/reducing valve to the X port​ on the DRG controller. Pilot pressure at X maps to pump cut-off pressure per the spring ratio (typically 0–10 bar pilot = 0–350 bar pump cut-off). The mechanical handwheel on the pump sets the upper limit — the actual cut-off is the lower of the two (handwheel limit vs. pilot-derived setpoint).

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.

• Suction: Keep inlet line short and generously sized; 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.