Castair C-FRS10 — 1" Filter/Regulator Combo, 250 PSI, 180 CFM
The C-FRS10 is a 1-inch NPT standard-size combination filter/regulator from Castair, a Minnesota-based cast iron air compressor manufacturer. This unit combines a 5-micron particulate filter with a built-in pressure regulator and gauge in one compact housing — fewer connection points, simpler installation, and less potential for leaks than running a separate filter and regulator in series.
At 1-inch NPT with a 180 CFM flow rating and 250 PSI maximum inlet pressure, this is a main-line unit. It belongs on the primary feed coming out of a large industrial or commercial compressor, or on a high-demand branch serving multiple stations. If your installation is 3/4-inch or smaller, look at the C-FRS34 or C-FRS12 — sizing this unit too large for the line costs more money and takes up more wall space without any benefit.
What This Unit Does
- 5-Micron Particulate Filtration: Catches pipe scale, rust particles, and airborne debris before they reach tools, cylinders, and air-operated equipment downstream.
- Integrated Pressure Regulation: Downstream pressure is set and held at the regulator, protecting equipment from swings in tank pressure during heavy draw cycles.
- Gauge Included: Live downstream pressure reading right at the unit — no separate gauge tee needed.
- 11 oz Bowl: Collects liquid water and condensed oil carryover. Manual drain standard. For high-cycle or high-humidity environments, add an automatic float drain to eliminate manual drain intervals.
- 1" NPT Female Inlet/Outlet: Standard threading — connects directly to pipe or fittings without adapters.
Where It Fits in the Air System
- Install downstream of the compressor tank and any aftercooler or refrigerated dryer, upstream of distribution or point-of-use equipment.
- For oil aerosol removal, add a Castair coalescing filter upstream. The C-CF10 is the 1-inch coalescer. Coalescing filters require a 5-micron prefilter — the C-FRS10 in front of the C-CF10 satisfies that requirement while also giving you line pressure regulation.
- The 5-micron element removes solid particulate. It is not a substitute for a dryer or aftercooler — address bulk liquid and moisture upstream first.
Castair Filter/Regulator Lineup — Match Size to Your Line
- C-FRM14 (1/4" Mini): 150 PSI max, 38 CFM, 1.5 oz bowl — light-duty single-tool drops
- C-FRS12 (1/2" Std.): 250 PSI max, 120 CFM, 8.5 oz bowl — most garage and small commercial installations
- C-FRS34 (3/4" Std.): 250 PSI max, 160 CFM, 8.5 oz bowl — larger shops with moderate multi-tool demand
- C-FRS10 (1" Std.): 250 PSI max, 180 CFM, 11 oz bowl — high-output main lines feeding multiple stations
When to Choose This vs. Stepping Down
Match the filter/regulator to the actual pipe size in your installation. If your main feed is 1-inch pipe, the C-FRS10 is right. If your installation is 3/4-inch throughout, the C-FRS34 is the correct call. Running a 1-inch unit on a 3/4-inch line adds cost and wall space with no performance gain.
If you need filtration only without pressure regulation, look at the C-FS10. If regulation only without a filter bowl is sufficient, look at the C-RS10. The combo unit earns its place when you want both functions in one housing with one fewer inline joint.
Technical Specifications
- Part Number: C-FRS10
- Port Size: 1" NPT Standard
- Connection Type: NPT Female Inlet and Outlet
- Maximum Inlet Pressure: 250 PSI
- Flow Rating: 180 CFM
- Filtration Grade: 5-Micron Particulate
- Bowl Capacity: 11 oz
- Gauge: Included
- Manufacturer: Castair, Spicer, Minnesota
Why Buy From Air Compressor Factory Direct?
We have stocked and sold Castair equipment since 2016 and know their full product line. When you call us, you get a straight answer on which size and configuration fits your specific system — not a guess from someone reading the same spec sheet you already found online. We offer free shipping on qualifying orders, full manufacturer warranty on all Castair products, and free technical support at 866-217-0063. If you are building or expanding a shop air system and want honest guidance, we are here for that conversation.
Call 866-217-0063 for quick answers and help!
