A10VO Series 31 vs Series 32: Which Pump Generation Do You Need?
If you are replacing or specifying an A10VO axial piston pump, you will meet two main series of the A10VO family: Series 31 and Series 32. Both are medium-pressure (280 bar nominal / 350 bar peak) open-circuit pumps of swashplate design — but they differ in size range, structure and control naming. This guide explains the difference so you order the right one.
The short version
- Series 31 is the classic, all-purpose generation. Sizes from 18 to 100 cm³/rev (140 covered in the Series 32 data sheet). Most existing machines in the field use Series 31.
- Series 32 is the optimized generation for high-power machines. Sizes from 45 up to 180 cm³/rev, with a strengthened bearing, quieter housing and an optional universal through drive.
Key differences at a glance
| Feature | Series 31 | Series 32 |
|---|---|---|
| Positioning | All-purpose medium pressure pump | Optimized for high power machines |
| Sizes | 18, 28, 45, 71, 88, 100 | 45, 71, 100, 140, 180 |
| Pressure | 280 / 350 bar | 280 / 350 bar |
| Flow control naming | DFR / DFR1 | DRF / DRS (same functions, new names) |
| Constant power control | DFLR | LA.D family (LA.DG / LA.DS) |
| Through drive | Optional (splined-coupling type) | Optional + universal through drive (U type) |
| Weights (71 / 100, no through drive) | 35.2 / 49.5 kg | 40.4 / 56.4 kg (reinforced) |
Three traps when replacing
- Control codes are renamed. Series 32 calls the same function DRF/DRS where Series 31 says DFR/DFR1. Do not compare codes literally — compare the function (load-sensing flow control with X port open vs plugged).
- Size 140 flanges differ. The 140 unit in Series 32 uses a different mounting pilot than the Series 31 140. Never assume interchangeability on size 140 — check the flange before ordering.
- Constant power lives elsewhere. Series 31 uses DFLR; Series 32 uses the LA.D family. If your circuit relies on constant power control, confirm the equivalent option on the generation you are ordering.
Which one should you order?
If you are replacing an existing Series 31 machine, stay with Series 31 — the mounting, ports and control naming match the original. If you are designing a new high-power machine, need 180 cm³/rev, or want the universal through drive and measurement port, Series 32 is the modern choice.
Not sure which generation your machine has? Send us the model code from the nameplate — it includes the series (e.g. …/31R-… vs …/32R-…) — and we will confirm the correct replacement.
