Castair Refrigerated Dryer Replacement Filter Element — .030 Micron (RD.030-S)
The Castair RD.030-S is a .030 micron replacement filter element for Castair refrigerated dryer pre-filter assemblies, S-series housing. The .030 micron rating sits between the finer RD.016-S (.016 micron) and the coarser RD.060-S (.060 micron) in the Castair replacement element lineup. Pre-filtration before a refrigerated dryer protects the stainless steel heat exchanger from oil mist that would otherwise coat the heat transfer surfaces and progressively degrade dew point performance over time.
Specific housing dimensions and compatibility data for the RD.030-S were not published on castair.net at time of writing. Contact 866-217-0063 with your dryer model and pre-filter housing to confirm this is the correct replacement element for your installation.
Filter Specifications
- Part number: RD.030-S
- Filtration rating: .030 micron
- Filter type: Coalescing replacement element (S-series housing)
- Application: Pre-filter for Castair refrigerated compressed air dryers
- Housing compatibility: S-series housing — contact 866-217-0063 to confirm
Choosing the Right Micron Rating
The choice between .016, .030, and .060 micron pre-filter elements depends on the oil content of your compressed air and the downstream application.
- .016 micron (RD.016-S): Highest filtration — use when oil carryover from the compressor is a concern, or for applications requiring the cleanest possible air entering the dryer
- .030 micron (RD.030-S, this part): Intermediate — appropriate for most shop applications with properly maintained compressor oil systems
- .060 micron (RD.060-S): Coarser pre-filter — use as a first-stage pre-filter upstream of a finer coalescing stage in a two-stage pre-filter arrangement, or for lower-sensitivity applications
If you are using a single pre-filter housing before your dryer, the .030 micron element balances filtration effectiveness with service life for most automotive shop and light industrial applications.
When to Replace
- Replace when the differential pressure indicator on your filter housing shows element loading
- More frequent replacement needed in dusty or high-oil-carryover environments
- Annual replacement minimum in normal shop use — more often in high-cycle operations
Pre-Filter System Context
- Castair requires a properly sized pre-filter before all refrigerated dryers — this is a warranty condition, not a recommendation
- Castair's C-CF series (.01 micron coalescing) is used for final point-of-use filtration after the dryer for critical applications like spray painting and instrument air
- The RD-series elements (RD.016-S, RD.030-S, RD.060-S) protect the dryer heat exchanger — they are pre-dryer elements
What Is in the Box
- 1x Castair RD.030-S replacement filter element, .030 micron
Why Buy From Air Compressor Factory Direct?
- Castair authorized: OEM replacement element
- Free shipping on qualifying orders
- Free tech support: 866-217-0063 — help selecting the correct micron rating and confirming housing compatibility
- Full dryer accessory lineup: All three RD filter ratings plus filter housings, dryer units, and installation accessories
Call 866-217-0063 for quick answers and help!
