An A4VSO model code describes a pump's configuration. It helps you identify displacement, control, rotation and mechanical interfaces before requesting a replacement. It does not, by itself, confirm that another pump will fit or perform correctly in your machine.
The Bosch Rexroth documents compared below use 14 ordering positions, not 14 characters. Some positions contain several characters; others carry no code for a standard version. This guide uses "model code" and "type code" for the same configuration string.
Start with the complete nameplate and the appropriate dated datasheet. Then decode the fields and check their combinations. This is a document-based identification guide; the drawings and specifications for the unit being offered remain essential to an order.
1. Choose the right datasheet before decoding
Three editions are relevant to the comparisons in this guide:
| Document | Scope used here |
|---|---|
| RE 92050/2023-06-15 | Metric type-code table used for the worked example |
| RE 92050/04.09 | Historical metric table used to check older entries |
| RA 92050-A/06.09 | North American table covering SAE and metric versions by size |
These are Bosch Rexroth documents hosted by third parties. The dates identify the editions used here; they are not a claim that an edition is the latest available or that a listed configuration is currently supplied.
Photograph the whole nameplate. The instruction manual RE 92050-01-B/2023-09-28, pp. 21 and 30 identifies Typ as the type code, MNR as the material number, SN as the serial number and FD as the manufacturing date. It also shows the rotation marking and an optional customer material number, CNR.
The manufacturing date helps narrow the document search. Preserve the type code and MNR together: the manual calls for both to be compared with the order confirmation before installation. MNR is a separate identifier, not another string to decode with the 14-position table.
In the North American table, AA4VS identifies the SAE version and A4VS the metric version. Treat the prefix as a starting clue. The complete code, size and interface drawings still need to agree.
2. A4VSO model code example: all 14 positions
This example illustrates the NG 180 entries in RE 92050/2023-06-15. It is a decoding exercise, not a stocked-product listing or a replacement approval.
A4VSO 180 DR /30 R -VPB 25 N00
| Position | Example value | Meaning in this edition |
|---|---|---|
| 01 | No code | Mineral oil and HFD fluid version; other fluid/version entries have restrictions |
| 02 | A4VS | Variable axial piston unit of swashplate design |
| 03 | No code | Without charge pump |
| 04 | O | Pump for an open circuit; this is the letter O |
| 05 | 180 | NG 180; maximum geometric displacement of 180 cm³/rev |
| 06 | DR | Pressure controller, one-sided swiveling; control datasheet 92060 |
| 07 | 30 | Series 3, index 0 |
| 08 | R | Clockwise when viewed on the drive shaft |
| 09 | V | FKM sealing material / HFD operation |
| 10 | P | Parallel keyed shaft to DIN 6885 |
| 11 | B | Metric four-hole mounting flange based on ISO 3019-2 |
| 12 | 25 | Lateral B/S SAE flange ports offset 90°, metric fastening threads; additional B1 opposite B, plugged on delivery |
| 13 | N00 | Without through drive |
| 14 | Absent | Filtration position is specified only for DS.. controls in this edition; DR is not DS |
Source: RE 92050/2023-06-15, pp. 2–5. The availability matrix and footnotes apply to individual sizes. These entries are not freely interchangeable options.
Check the combinations as well as the individual meanings:
- Size and series: the table assigns code 10 to NG 40 and 71, with 11 shown only for HD and EP controls. Code 30 applies to the listed NG 125–1000 sizes. NG 180 with 30 is consistent with that table.
- Size and flange: B applies to the listed NG 40–370 sizes; H applies to NG 500–1000. A different pairing needs configuration-specific clarification.
- Port plate and through drive: port plate 13 is restricted to N00 or K.. through drives. A 13/U.. combination cannot be validated from this standard table.
If a pairing does not resolve, preserve the recorded code. Check for a different edition, incomplete transcription or a configuration outside the standard table before calling it an error.
3. Read displacement, rotation and control correctly
Displacement is a maximum geometric value. The size entry refers to Vg max in cm³ per revolution. The actual displacement changes with the swashplate position. A size designation is therefore not a guaranteed operating flow.
Rotation has a defined viewing direction. R means clockwise and L counter-clockwise, viewed on the drive shaft. Compare the drive and nameplate using that convention, as stated in the instruction manual, pp. 21 and 31.
The control code leads to another document. It identifies the control family, while the applicable control sheet supplies circuit details, setting ranges and port requirements.
| Control in the 2023 references | Datasheet number |
|---|---|
| DR, DP, FR, DFR | 92060 |
| LR2, LR3, LR2N, LR3N | 92064 |
| MA, EM | 92072 |
| HM, HS5, EO | 92076 |
| HD | 92080 |
| DS2 / DS3 | 92057 / 92059 |
| DFE1 | 92088 |
| SYDFE | 30035 |
Sources: RE 92050/2023-06-15, p. 2 and RE 92050-01-B/2023-09-28, p. 5.
This is a 2023 reference map, not a universal map for historical codes. Match the RE/RA designation and revision too. The historical sheets list DS1 against 92056; that does not establish interchangeability with DS2 or DS3.
For through drives, K denotes the option without conversion and U a universal through drive. Read the complete suffix and its size-specific flange/coupler combination in the applicable table, rather than treating K or U alone as a complete interface specification.
For the commercial product overview, see Sheungchak's A4VSO pump page. Use the complete code and the offered unit's drawing when discussing a configuration.
5. Pressure depends on configuration
Do not assign a pressure rating from "A4VSO" alone. In RE 92050/2023-06-15, the working-pressure table distinguishes the port plates:
| Port plate | Nominal pressure | Maximum pressure | Scope |
|---|---|---|---|
| 13 or 25 | 350 bar | 400 bar | Applicable configuration and fluid conditions still apply |
| 36 | 380 bar | 420 bar | Listed for the NG 370 high-speed version with selected controls |
The maximum-pressure values are subject to a 1-second single operating period, 300 hours total operating time at maximum pressure, and approximately one million cycles maximum. They are operating limits, not continuous ratings or service-life promises.
Port plate 36 also has control-dependent minimum working pressures: 30 bar for the stated flow or remotely controllable pressure-control arrangements, and 40 bar for DFE1 and HS5(E)V. Separately, the table lists 15 bar absolute as the high-pressure-side minimum at B, dependent on rotational speed and swivel angle; lower values are on request.
The stated working-pressure range assumes mineral-oil-based fluid. It does not establish settings for every hydraulic fluid or authorize increasing pressure in an existing system. Source: RE 92050/2023-06-15, pp. 2–3 and 8.
6. Keep performance and filtration separate from code reading
Use the size and execution version to select the performance table. Its theoretical flow, power and torque values exclude efficiency and tolerances. A sales table or a displacement calculation cannot replace the applicable operating limits.
For the standard rotary group, the cited speed conditions include mineral-oil-based fluid and optimum viscosity of 16–36 mm²/s. The nnom row at Vg max refers to 1 bar absolute at suction port S. The nmax row has separate increased-inlet-pressure and reduced-displacement conditions. High-speed versions have separate tables. Do not transfer a footnote from one parameter row to another. See RE 92050/2023-06-15, pp. 9–11.
For filtration, N00 at position 13 means no through drive. It must not be confused with a following N at position 14:
- If N or Z is explicitly recorded and the applicable table covers the control, read the specified no-filter or intermediate/sandwich-plate-filter option. It does not describe all filtration in the hydraulic system.
- If no trailing character is recorded, check whether the position applies and whether the transcription is complete. Absence alone does not establish the filtration configuration.
- If the recorded suffix conflicts with the table, retain it and seek clarification. The 2023 manual's illustrative LR2 nameplate ends in N00N, while the 2023 datasheet restricts position 14 to DS.. controls. That illustration cannot settle the ordering rule for an actual unit.
Sources: RE 92050/2023-06-15, p. 5, RA 92050-A/06.09, p. 4 and RE 92050-01-B/2023-09-28, p. 21.
7. Prepare the details for an A4VSO inquiry
Before requesting a quotation, assemble:
- A clear photograph of the entire nameplate, including Typ, MNR, SN, FD and rotation.
- The complete code as recorded, including punctuation and any uncertain characters.
- The equipment application, operating speed, working pressure, fluid and control requirements.
- Available installation drawings and photographs of the shaft, flange, ports and through drive.
- Required quantity and delivery destination.
Compare the code, the offered unit's drawing and the installed interfaces together. Check size/series, rotation, seals, control, flange, shaft, port plate and through drive as a combination. Request written clarification for unresolved fields rather than accepting a similar-looking designation.
The manufacturer's instruction manual, p. 5 identifies the order confirmation and installation drawing as necessary documentation. Its project-planning notes, p. 78 call for a binding installation drawing before design finalization. Code reading also cannot establish the condition or service history of a used pump.
Request an A4VSO quotation from Sheungchak: use the inquiry page, or email the nameplate photographs and requirements to info@hydraulicsc.com. Ask the quotation to identify the supplied manufacturer/brand, full configuration, drawing, applicable specifications, availability and lead time.
The Bosch Rexroth references in this guide explain the documented coding system. They do not establish the manufacturer, authorization status or interchangeability of a product offered by another supplier; those details belong in the quotation and supporting documentation.
