A4VSO355DRG/30L-PPB13N00 German made Rexroth hydraulic piston pump

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

DRG​ = DR pressure compensator with remote pilot port (X)​ — allows the pressure cut-off setpoint to be changed remotely by applying pilot pressure to port X, instead of only adjusting the handwheel on the pump.

Frequently Asked Questions (FAQ)

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

A:

• DR: Direct-operated pressure compensator — mechanically sets cut-off pressure on the pump; pump destrokes when system pressure reaches set value.

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

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

  Choose DRG when you need remote pressure adjustment; choose DFR1 when you need load-sensing flow control.

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. Always verify motor rotation direction 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​ (common on European industrial units). "25" = SAE flange ports​ (4-bolt flanged). Ensure your hose/fitting kits match the thread type — "13" needs G-threaded adaptors, "25" needs SAE flange halves.

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

A: Apply pilot pressure to the X port​ (typically 0–10 bar pilot = 0–350 bar pump cut-off, ratio depends on specific DRG spring range). A common setup uses a 3-way solenoid or reducing valve to switch between two pilot pressures, giving two remote pressure stages. The mechanical handwheel still provides a max-limit safety stop.

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 #1 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.