The Castair F-10D-050 is a complete intake air filter assembly for piston compressor pumps with a 1/2" NPT inlet port. It mounts on the pump head intake port, filters incoming air through a paper element (the 10D element), and quiets the sharp intake pulse that unprotected pump ports produce. The 1/2" NPT size is the most common inlet size in the F-10D series and fits a wide range of Castair single-stage piston pumps.
What This Filter Does
A piston compressor draws in shop air on every intake stroke. Without filtration, that air carries concrete dust, metal particles, carbon deposits, and other airborne abrasives directly into the cylinder bore and across the valve seats. The F-10D-050 threads onto the pump intake port and removes those particulates with a paper filter element before the air reaches the compression chamber.
The filter housing is also an intake silencer — it substantially reduces the thumping intake noise that characterizes unfiltered piston pumps.
Key Specifications
- Part Number: F-10D-050
- Inlet Size: 1/2" NPT
- Outer Diameter: 3.25"
- Overall Height: 3.50"
- Flow Rating: 12 CFM
- Filter Element: 10D paper element (ID 1-1/8", OD 2-1/4", height 2-1/4")
- Construction: Cast iron
F-10D Series — Available Configurations
Three inlet sizes, same compact housing (3.25" OD, 3.50" height, 12 CFM), same 10D replacement element:
- F-10D-025 — 1/4" NPT inlet
- F-10D-038 — 3/8" NPT inlet
- F-10D-050 — 1/2" NPT inlet (this model)
The 1/2" inlet is the most common size in this series. For larger pumps (20-60 CFM) with 1/2" through 1-1/2" inlet requirements, Castair offers the S-16D and S-20DP series with foam pre-filters.
When Does a Shop Need This
- Replacing a broken, cracked, or missing intake filter on a Castair pump with a 1/2" inlet
- The existing housing is intact but the element seat is damaged and the element will not seal properly
- Building or rebuilding a Castair piston pump and need the complete intake assembly
- The compressor is running louder than normal at intake — a missing or heavily clogged filter amplifies intake noise significantly
Replacement Element
The F-10D-050 uses the Castair 10D paper element (ID 1-1/8", OD 2-1/4", height 2-1/4"). Service interval depends on shop conditions — dusty shops need more frequent changes. A plugged intake element forces the pump to work harder and run hotter, accelerating wear. Keep a spare 10D on hand.
Why Buy From OEM Diagnostic Tools?
OEM Diagnostic Tools has supplied professional shop equipment and components since 2016. We stock Castair parts so shops get what they need without distributor delays. Free shipping on qualifying orders, free tech support at 866-217-0063, and full manufacturer warranty on every part. Call us if you need help confirming the correct inlet size for your pump.
Call 866-217-0063 for quick answers and help!
