Castair C-FRS12 — 1/2" Filter/Regulator Combo, 250 PSI, 120 CFM
The C-FRS12 is a 1/2-inch NPT standard-size combination filter/regulator from Castair, built for the most common air system installation size in garages, small shops, and commercial settings. It pairs a 5-micron particulate filter with a built-in regulator and pressure gauge in one compact body — giving you filtration and pressure control in one connection point instead of two separate components.
At 120 CFM flow capacity with a 250 PSI maximum inlet pressure, the C-FRS12 handles the output of most single-unit shop compressors feeding a 1/2-inch main line. It is the right choice for point-of-use installation at a workstation or on the primary feed of a smaller shop air system. If you are running a 3/4-inch or 1-inch main line with higher demand, step up to the C-FRS34 or C-FRS10.
What This Unit Does
- 5-Micron Particulate Filtration: Removes pipe scale, rust, and solid debris before they reach air tools, spray guns, and air-operated equipment — extends tool life and prevents fouling of sensitive components.
- Integrated Pressure Regulation: Maintains consistent downstream pressure regardless of pressure swings in the supply tank. Tools with rated inlet pressures below your line pressure need a regulator — this gives you that in the same housing as the filter.
- Gauge Included: Live downstream pressure display. You set it once, and you can confirm it anytime without a separate gauge installation.
- 8.5 oz Bowl: Collects liquid water and oil carryover from the compressed air stream. Drain manually or add an automatic float drain for unmanned operation.
- 1/2" NPT Female Connections: Standard threading — fits directly to pipe or fittings.
Where It Fits in the Air System
- Install downstream of the compressor tank and any aftercooler or dryer, on the main feed or at individual workstation drops.
- Works as a prefilter ahead of a Castair coalescing filter when oil aerosol removal is also needed. The C-CF12 is the 1/2-inch coalescer.
- Common installation: main line filter/regulator set at 90 PSI feeding spray booths, body shops, or production lines where consistent pressure matters as much as cleanliness.
Castair Filter/Regulator Lineup
- C-FRM14 (1/4" Mini): 150 PSI max, 38 CFM — light-duty single-tool drops
- C-FRS12 (1/2" Std.): 250 PSI max, 120 CFM — most garage and small commercial installations
- C-FRS34 (3/4" Std.): 250 PSI max, 160 CFM — larger shops with moderate multi-tool demand
- C-FRS10 (1" Std.): 250 PSI max, 180 CFM — high-output main lines
When to Choose This vs. Stepping Up or Down
The C-FRS12 covers most single-station and small shop applications on 1/2-inch lines. If you are running multiple tools simultaneously off a 1/2-inch feed and hitting pressure drop across the filter at peak demand, you may need to upsize the main line — the filter is not the bottleneck, the pipe is. If your main line is 3/4-inch or 1-inch, use the corresponding larger filter/regulator from the start.
Need filtration only without a regulator? Look at the C-FS12. Need a regulator only without the filter bowl? The C-RS12 is the 1/2-inch regulator. The combo makes sense when you want both functions in one connection point.
Technical Specifications
- Part Number: C-FRS12
- Port Size: 1/2" NPT Standard
- Connection Type: NPT Female Inlet and Outlet
- Maximum Inlet Pressure: 250 PSI
- Flow Rating: 120 CFM
- Filtration Grade: 5-Micron Particulate
- Bowl Capacity: 8.5 oz
- Gauge: Included
- Manufacturer: Castair, Spicer, Minnesota
Why Buy From Air Compressor Factory Direct?
We have sold and supported Castair equipment since 2016. Call us at 866-217-0063 and we will tell you exactly which size filter/regulator fits your installation — no upsell, just the right answer. Free shipping on qualifying orders, full manufacturer warranty, free tech support. If you are setting up or expanding your shop air system, we have the knowledge to help you get it right the first time.
Call 866-217-0063 for quick answers and help!
