Donaldson
Donaldson P171821
Industrial filter element
Donaldson P171821 specifications
The Donaldson P171821 is a 20µm microglass filter element. It measures 4.18" OD x 0.4" ID x 18.31" long. Filtration efficiency is rated at 1000 per ISO 16889. Seals are BUNA, rated for -13°F to 250°F. Collapse pressure rating is 145 PSID. 20 verified cross-references are available from aftermarket manufacturers. Specifications verified. Last reviewed: May 2026
Physical fit
- Outer Diameter (O.D.)
- 4.18"OEM-published
- Inner Diameter (I.D.)
- 0.4"OEM-published
- Overall Length
- 18.31"OEM-published
- Micron Rating
- 20µmOEM-published
- Seal Material
- BUNAOEM-published
- Connection / Thread
- Not yet verified from an OEM source
Performance: Donaldson published values
These are Donaldson's own published numbers. Performance specs differ by brand and are never inherited across cross-references.
- Efficiency (ISO 16889)
- 1000
- Media Type
- MICROGLASS
- Collapse Rating
- 145 PSID
- Flow Direction
- INSIDE-OUT
- Operating Temperature
- -13°F to 250°F
What replaces the Donaldson P171821?
20 published cross-references on file. Select to expand.
What replaces the Donaldson P171821?
20 published cross-references on file. Select to expand.
A cross-reference confirms dimensional fit and micron rating, not performance equivalence. Beta ratio, collapse rating, media, and service life can differ between brands.
Published cross-references
| Part Number | Manufacturer | Match |
|---|---|---|
| SFTXW2-18-25UM | Swift Filters | Sourced |
| FFPAVL1109425ABS | Finn | Sourced |
| FR722G25 | Fram | Sourced |
| FT2504P25A | Vickers | Sourced |
| TXW5-ACC25 | Fairey Arlon | Sourced |
| TXX5A-10 | Fairey Arlon | Sourced |
| RC240CV1 | Sofima | Sourced |
| TX30EAL202N6 | Purolator | Sourced |
| VR151B3C20 | Vickers | Sourced |
| FRE300EN | Zinga | Sourced |
| TXW5A-GDL20 | Fairey Arlon | Sourced |
| FC1094F025XS | Finn | Sourced |
| FC1094Q020BS | Parker | Sourced |
| TXW5A-GDL20-B | Fairey Arlon | Sourced |
| PR4406 | Parker | Sourced |
| TXW5A-20 | Fairey Arlon | Sourced |
| ER151B4C20 | Western | Sourced |
| FT2504A25A | MP Filtri | Sourced |
| TXW5-A20-B | Parker | Sourced |
| TXW5A-20-B | Fairey Arlon | Sourced |
Application & Compatibility
The DONALDSON P171821 is designed for use in hydraulic and lubrication filtration systems. With a 20µm rating, this element is suitable for pump and component protection in industrial hydraulic circuits. BUNA seals provide compatibility with standard petroleum-based fluids and mineral oils.
The 145 PSID collapse rating indicates the maximum differential pressure this element can withstand during cold starts or bypass conditions without structural failure. Ensure your system's maximum differential pressure does not exceed this rating.
Frequently Asked Questions
What micron rating is the Donaldson P171821?
What are the dimensions of the Donaldson P171821?
What seal material does the Donaldson P171821 use?
Is there a cross-reference for the Donaldson P171821?
What is the collapse pressure rating of the Donaldson P171821?
What is the operating temperature range for the Donaldson P171821?
How this entry is verified
Every specification on this page names its source: manufacturer documents first, distributor catalogs second, decoded part-number patterns labeled as such. When a value has not been verified from an OEM source, the cell says so. Cross-references are fit claims, never performance claims.
Request a quote for the Donaldson P171821
Tell us where to send it and we'll get you pricing and availability within 24 hours. Leave a number and we'll call you back within the hour.
Verified Cross-References
520,000+ verified cross-references on file
Fast Response
Quotes and answers within 24 hours
Expert Support
Real filtration specialists, not call centers