Castair Replacement Air Filter Element for D10 Rotary Pump (RAFD10)
The Castair RAFD10 is the replacement paper air filter element for the D10 rotary screw pump, used in the 25 to 40 HP range of Castair rotary screw compressors. Dimensions are ID 6-3/8", OD 9-1/2", HGT 5". If you are running a D10 air end on your Castair rotary screw unit, this is the correct filter replacement — confirm your air end model before ordering, as D3/D4, D6/D62, G11, and P75 air ends all use different filter sizes that are not interchangeable.
Castair designs their rotary screw compressors around off-the-shelf automotive-style paper elements specifically so that filter changes are straightforward and parts are consistently available. The RAFD10 is a paper element — not foam, not oil-bath — which means it provides consistent filtration performance until replacement interval and gives a clear visual indicator when it needs changing. Keeping a clean air filter on a rotary screw compressor is not optional maintenance. A restricted air filter raises inlet temperature, increases oil carryover, and accelerates air end wear. Change it on schedule.
Filter Specifications
- Part number: RAFD10
- Filter type: Paper element, dry-type
- Inside diameter (ID): 6-3/8"
- Outside diameter (OD): 9-1/2"
- Height (HGT): 5"
- Application: D10 rotary pump air end
- Horsepower range: 25-40 HP Castair rotary screw compressors
Compatibility — Verify Your Air End Before Ordering
- RAFD10: D10 air end — ID 6-3/8", OD 9-1/2", HGT 5" (this part)
- RAFD16: D16 air end — ID 6-3/8", OD 9-1/2", HGT 7-7/8" (50-60 HP range)
- RAFD6-62: D6 and D62 air ends — ID 4-3/4", OD 6-1/8", HGT 2-7/8"
- RAFD3-4: D3, D31, D4 air ends — ID 2-7/8", OD 4-5/8", HGT 2-7/16"
- RAFG11: G11 air end — ID 2-5/8", OD 3-7/8", HGT 3-1/8"
The D10 and D16 share the same OD and ID but differ in height. Do not substitute RAFD16 for RAFD10 or vice versa — the incorrect height will affect sealing and filter performance.
When to Replace
- Scheduled interval: Follow the hour meter on your compressor — Castair recommends checking air filter condition as part of routine maintenance intervals
- Visible indicator: Paper element shows dirt accumulation visually — inspect regularly in high-dust environments
- Performance indicator: Rising operating temperature with consistent ambient temperature and load is often the first sign of a restricted air filter on a rotary screw unit
- PM kit option: MKD10 preventative maintenance kit covers the D10 air end and includes 2 air filters, 4 oil filters, 1 separator filter, and 5 gallons of synthetic CAST-LUBE oil — saves 10% vs. individual purchases
What Is in the Box
- 1x Castair RAFD10 paper air filter element
Why Buy From Air Compressor Factory Direct?
- Castair authorized: Correct OEM replacement element — no guessing on dimensions
- Free shipping on qualifying orders
- Free tech support: 866-217-0063 — confirm your air end model and correct filter before ordering
- Full filter lineup in stock: All Castair rotary pump filter elements available, plus oil filters and separator filters
Call 866-217-0063 for quick answers and help!
