A4VSO250LR2/30L-PPB13N00 German Rexroth A4VSO250 piston pump

💡 Cod

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

LR2​ = Hydro-mechanical constant power control (two-setting hyperbolic curve), automatically reduces displacement as system pressure rises to keep input power ≤ set limit—ideal for direct-coupled electric motor drives.

Frequently Asked Questions (FAQ)

Q1: What does "LR2" control mean and when should I choose it over DR or DFR?

A: LR2 = Hydro-mechanical Constant Power (Hyperbolic) Control. It uses a spring/piston arrangement to reduce pump displacement as pressure increases, keeping absorbed drive power roughly constant along a hyperbolic curve.

• Choose LR2​ when driving the pump with a fixed-power electric motor and you want to utilize full motor HP without overloading at high pressure.

• Choose DR (Pressure Control / Load Sense)​ for constant-pressure systems.

• Choose DFR / DFR1 (Pressure + Flow Control / Load Sensing)​ for energy-saving systems where flow demand varies with load.

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

A: Only if your drive arrangement allows. "L" = CCW viewing shaft end, "R" = CW viewing shaft end. They are not interchangeable​ unless you reverse the motor rotation or re-orient the coupling. Always verify motor rotation direction and shaft-end view before ordering. The pump body and port orientation are otherwise identical.

Q3: Does A4VSO250 require a case drain line? How should it be plumbed?

A: Yes, a case drain (leakage / housing drain) line is mandatory.​ Route it directly back to the tank above the oil level or via a standpipe ≤ 0.5 bar backpressure. Never block it or connect it to the suction line—excessive case pressure will blow the shaft seal. The case must also be filled with clean hydraulic oil before first start-up.

Q4: Can this pump be used in closed-loop (hydrostatic transmission) circuits?

A: No.​ A4VSO is designed exclusively for open-circuit​ applications. For closed-loop hydrostatic transmissions (e.g., travel drives on excavators), use A4VG or A6VM/A2FM series with charge pump.

Q5: What are the critical installation & filtration requirements?

A:

• Filtration: System should maintain cleanliness ≤ NAS 9 (≈ ISO 4406 17/15/12) with a 10µm or finer return/full-flow filter — contamination is the #1 cause of premature failure.

• Suction: Keep inlet line short, generously sized, and use a 100–150 mesh suction strainer. Minimum inlet pressure 0.8 bar abs.

• Alignment: Use a flexible coupling; do NOT impose radial/axial loads on the pump shaft from the motor.

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

Q6: Is the seal NBR (P) or FKM (V)? Can I run water-glycol (HFC) fluid?

A: Standard PPB13N00​ with code "P" seal = NBR (Nitrile), suitable for mineral oils (HLP). NBR is not compatible with HFC (water-glycol) or phosphate ester (HFD). For HFC fluids, you need the V (FKM/Viton) seal version​ — but even then confirm compatibility with Rexroth fluid table, as some HFC blends can still affect FKM. Pure water or HWBF is not recommended for A4VSO.