Castair Replacement Air Filter Element for G11 Rotary Pump (RAFG11)
The Castair RAFG11 is the paper air filter element for the G11 rotary screw pump air end. Dimensions: ID 2-5/8", OD 3-7/8", HGT 3-1/8". The G11 air end is used in the 5 to 15 HP range of Castair rotary screw compressors as an alternative to the D-series and P75 air ends. If your unit uses the G11, the RAFG11 is the only correct replacement filter — the dimensions are specific to this air end housing and are not interchangeable with RAFD3-4, RAFD6-62, or P75-series elements. At $34.73, the RAFG11 is priced slightly higher than some other Castair filter elements, reflecting the G11 geometry.
Filter Specifications
- Part number: RAFG11
- Filter type: Paper element, dry-type
- Inside diameter (ID): 2-5/8"
- Outside diameter (OD): 3-7/8"
- Height (HGT): 3-1/8"
- Application: G11 rotary pump air end
- Horsepower range: 5-15 HP Castair rotary screw compressors with G11 air end
G11 Air End Identification
Castair uses both G-series and D-series air ends across their rotary screw lineup. If your compressor model ends in "G11" (e.g., R738VG11), you have a G11 air end and need the RAFG11 filter. If your model ends in "75" or uses the D-series designation, you need a different filter. Check the compressor nameplate or your original documentation if unsure — call us at 866-217-0063 and we can confirm based on your model number.
Air End Filter Cross-Reference
- RAFG11 (this part): G11 air end — 5-15 HP — ID 2-5/8", OD 3-7/8", HGT 3-1/8"
- RAFD3-4: D3, D31, D4 — 5-10 HP — ID 2-7/8", OD 4-5/8", HGT 2-7/16"
- RAFD6-62: D6, D62 — ID 4-3/4", OD 6-1/8", HGT 2-7/8"
- RAFD10: D10 — 25-40 HP — ID 6-3/8", OD 9-1/2", HGT 5"
- RAFD16: D16 — 50-60 HP — ID 6-3/8", OD 9-1/2", HGT 7-7/8"
PM Kit
- MKG11: G11 air end PM kit — includes 2 RAFG11 air filters, 4 oil filters, 1 separator filter, 5 gal CAST-LUBE synthetic oil (saves 10% vs. individual purchases, covers 5-15 HP G11 range)
Maintenance Notes
- Inspect at each oil change — more frequently in dusty environments
- The G11 air end is a higher-output design — do not let filter maintenance slide on machines running at or near 100% duty
- Oil filter for G11: ROFD3-4-G11 spin-on
- Separator filter: RSFD3-4-6-G11-P75 spin-on
What Is in the Box
- 1x Castair RAFG11 paper air filter element
Why Buy From Air Compressor Factory Direct?
- Castair authorized: OEM replacement element with confirmed G11 dimensions
- Free shipping on qualifying orders
- Free tech support: 866-217-0063 — we can confirm G11 vs. D-series identification from your model number
- MKG11 PM kit available: Full G11 maintenance kit in stock
Call 866-217-0063 for quick answers and help!
