Castair C-FRS34 — 3/4" Filter/Regulator Combo, 250 PSI, 160 CFM
The C-FRS34 is a 3/4-inch NPT standard-size combination filter/regulator from Castair. It is the mid-range unit in the FRS lineup — larger than the 1/2-inch C-FRS12 for shops that run multiple tools or have higher-flow needs, and a step below the 1-inch C-FRS10 that goes on the largest main feeds. If your shop runs a 3/4-inch main air line, this is the filter/regulator that belongs on it.
The C-FRS34 delivers 160 CFM flow capacity at up to 250 PSI inlet pressure, with 5-micron particulate filtration and an integrated gauge. It handles the output of most mid-size commercial and industrial compressors and covers multi-station installations where the main distribution line is 3/4-inch pipe.
What This Unit Does
- 5-Micron Particulate Filtration: Blocks pipe scale, rust, and solid contamination from reaching downstream tools and equipment. Critical for spray guns, air-operated cylinders, and any equipment with tight tolerances.
- Built-In Pressure Regulator: Holds downstream pressure steady regardless of fluctuations in tank pressure. Set it once — it maintains your target pressure through draw cycles.
- Gauge Included: Downstream pressure visible at the unit. No additional fittings or gauges needed.
- 8.5 oz Bowl: Captures liquid water and oil condensate. Manual drain as standard; automatic float drain available as an add-on for continuous unmanned operation.
- 3/4" NPT Female Connections: Standard threads, no adapters needed for 3/4-inch pipe or fittings.
Where It Fits in the Air System
- Main line installation immediately downstream of the compressor tank and any aftercooler or refrigerated dryer.
- Can serve as the prefilter ahead of a Castair C-CF34 coalescing filter when oil aerosol removal is also required.
- Ideal for auto body shops, fabrication shops, and production environments running 3/4-inch main lines with multiple drops.
Castair Filter/Regulator Lineup
- C-FRM14 (1/4" Mini): 150 PSI max, 38 CFM — single-tool, light-duty drops
- C-FRS12 (1/2" Std.): 250 PSI max, 120 CFM — most garage and small shop setups
- C-FRS34 (3/4" Std.): 250 PSI max, 160 CFM — mid-size shops, 3/4-inch main lines
- C-FRS10 (1" Std.): 250 PSI max, 180 CFM — high-output main lines, multiple stations
When to Choose This vs. Stepping Up or Down
The C-FRS34 is sized for 3/4-inch installations. If your main line is 1/2-inch, the C-FRS12 is the right fit — running a 3/4-inch unit on a 1/2-inch line costs more and adds unnecessary bulk. If you are running 1-inch pipe with high simultaneous tool demand, step up to the C-FRS10.
Filtration only without regulation? Look at the C-FS34. Regulation only without a filter bowl? Look at the C-RS34 — note that C-RS34 is not listed in the standard Castair lineup, so contact us for availability. The combo unit makes the most sense when you want both functions in a single housing at the lowest installed cost.
Technical Specifications
- Part Number: C-FRS34
- Port Size: 3/4" NPT Standard
- Connection Type: NPT Female Inlet and Outlet
- Maximum Inlet Pressure: 250 PSI
- Flow Rating: 160 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 air system components since 2016. Call 866-217-0063 and we will confirm the right filter/regulator size for your specific line and compressor — no guesswork, no upsell. Free shipping on qualifying orders, full manufacturer warranty, free technical support on every order.
Call 866-217-0063 for quick answers and help!
