Donaldson · Hydraulic Catalog · inline line
P551551 filter element: specifications & equivalents
The P551551 is a Donaldson inline-line hydraulic filter element, built with cellulose media, rated at 7 µm class. Verify against the current manufacturer data sheet before ordering.
OD/ID dimensions, collapse pressure and bypass settings are not printed in the filter-element choice table and are pending extraction from the housing dimension pages. Verify against the current Donaldson data sheet before ordering.
Specification table
| Parameter | Value |
|---|---|
| Filter type | inline line |
| Media | Cellulose |
| Filtration rating | 7 µm |
| Rating basis | nominal |
| Length | 136 mm |
| Integral bypass valve | none (housing/valve-dependent) |
| Manufacturer part no. | P551551 |
| Source catalog | Donaldson Company: Hydraulic Filtration Product Guide (F112100-ENG) |
| Last verified | 2026-09-28 |
Sources: Donaldson Company — Hydraulic Filtration Product Guide (F112100-ENG) — accessed 2026-09-27.
Donaldson® and all model designations are trademarks of their respective owners, used here for identification only — ElementRef is an independent reference site, not an authorized Donaldson distributor.
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| ↔ 921999 | Parker | partial | Parker ParFit interchange — Donaldson P551551 replaced by Parker 921999. Envelope match; verify grade and seals. |
| ↔ A110C10/9 | Filtrec | partial | Filtrec's official Cross Navigator maps DONALDSON P551551 to FILTREC A110C10/9 as a direct replacement, publishing the FILTREC element's OD/ID/height envelope and media grade. Rated micron differs (7 vs 10 µm) — verify efficiency class and collapse/seal for the housing before substituting. |
| ↔ HF6057 | Fleetguard | partial | Fleetguard's online catalog lists P551551 as an interchange for HF6057. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
| ↔ P10 | Schroeder Industries | partial | Schroeder online cross-reference (DONALDSON); envelope match — verify grade and seals. |
| ↔ WD940/2 | MANN-FILTER | partial | MANN-FILTER's online catalog lists P551551 (DONALDSON) as a comparison number for WD9402. Envelope cross-reference; verify micron grade, collapse rating and seal configuration before substituting. |
Interchange levels: full catalog-confirmed drop-in · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
Full chart: Donaldson cross reference chart →
How the P551551 model number is decoded
- P551551Donaldson hydraulic filter element part number per the Hydraulic Filtration Product Guide (F112100-ENG).
- SP15/25Product family: SP15/25.
- CelluloseFilter media: Cellulose.
- 7 μmNominal filtration rating at βx(c) = 2 per ISO 16889.
Typical equipment & applications
- Donaldson SP15/25 hydraulic filter housing
Selection pitfalls — read before you substitute
- “10 µm nominal” and “12 µm at β1000” can describe the very same media — one is reported at β≥200, the other at β≥1000 per ISO 16889. Compare ratings at the same Beta test point, not just the printed micron number.
Frequently asked questions
What micron rating does P551551 use?
What replaces the P551551 filter element?
How do I read the P551551 part number?
Other models in the Hydraulic Catalog series
All 360 →Reviewed & verified by the ElementRef engineering desk against Donaldson Company on 2026-09-28. Read our editorial & correction policy.