The most common buyer problem we hear is not price — it is getting the right part the first time. A compressor nameplate, a worn part number, and a service history between you and the correct filter. This guide walks through exactly how to identify the right filter, what the part numbers mean, and how cross-referencing works so you never install the wrong element.
Where to find your part number
Every compressor has at least three honest sources for the correct part number:
If the number is worn away, the next fallback is the geometry: measure the outer diameter, height, and the sealing arrangement, and note the OEM brand of compressor. A competent cross-reference can usually reconstruct the correct part from those three dimensions.
What the OEM part number actually encodes
OEM part numbers are rarely random. On most filters they encode, in some order, the product family, the media grade or application, and a unique variant. Two examples of how that matters:
This is exactly why 'compatible with' lists exist: a quality supplier maintains a cross-reference from each OEM number to the correct replacement element, including superseded numbers.
How cross-referencing works in practice
A genuine cross-reference is a technical match, not a guess by similarity. When you give a supplier your OEM number, they check four things before saying 'yes, matches':
What a good supplier does NOT do is claim 'fits all brands' or match only the thread/overall height. A filter's performance lives in the media and the sealing, not the silhouette.
The 9-character recipe for finding your filter
Have this string ready whenever you text or call a supplier — it takes 30 seconds and eliminates nearly every wrong-part mishap:
Compressor brand + model + kW, then OEM part numbers for air filter / oil filter / separator, then any info from the existing element (photos work great on WhatsApp).
With that one string, a supplier who maintains a real cross-reference system can confirm fitment before you order. If the supplier needs only the compressor model and 'send a photo' — good sign. If they need nothing at all — be suspicious.
Common part-number mistakes and how to avoid them
The discipline that saves the most money and time is simple: write down the part numbers from the manual into the machine's logbook, and re-verify against the element itself at every change. Over a few services, you build an accurate parts list per machine that makes the next order a text message.
Ordering from Kenrax
Kenrax maintains a cross-reference for the major screw compressor brands — Atlas Copco, Ingersoll Rand, Elgi, Kaeser, Chicago Pneumatic, Kirloskar, Gardner Denver, Sullair and others. Send us the OEM numbers from your manual or a photo of the element, and we confirm the match before dispatch. You can order these directly from Kenrax on WhatsApp (or check price on the product pages).
The one-line summary
Find the OEM numbers on the manual and the element, give the supplier the full 'brand + model + OEM numbers' string, and only accept a cross-reference that has verified media, dimensions, and sealing. The right filter the first time is cheaper than any filter that is slightly wrong.