Castair C-RS34 3/4" Standard Air Regulator with Gauge
The Castair C-RS34 is a 3/4" NPT standard regulator built for commercial and industrial air compressor systems. If you're running a shop air system and need accurate, stable downstream pressure control at 3/4" line sizes, this is a straightforward, dependable regulator. It handles up to 250 PSI inlet pressure and flows up to 162 CFM — enough capacity for most shop air main lines at that pipe size. The included gauge gives you a clear read on downstream pressure so you can set it and trust it.
What This Regulator Does
- Function: Reduces and maintains downstream air pressure to the level required by air tools, paint equipment, or pneumatic devices
- Port Size: 3/4" NPT standard — fits directly into 3/4" threaded pipe connections on your main air distribution line
- Max Inlet Pressure: 250 PSI — compatible with all standard commercial air compressor systems
- Flow Capacity: 162 CFM — handles high-demand shop environments with multiple tools running simultaneously
- Gauge Included: Built-in pressure gauge for immediate downstream pressure visibility without a separate instrument
Where This Fits in Your Air System
Regulators go downstream of your tank and dryer, upstream of your distribution drops or specific equipment. The C-RS34 is sized for 3/4" systems — shops running 3/4" main lines to paint booths, body work stations, or general air drops. At 162 CFM, it won't be a bottleneck for most reciprocating or mid-size rotary screw compressor setups at that line size.
Castair Regulator Lineup
Castair offers regulators in standard NPT sizes. Choose the size that matches your existing pipe:
- C-RE14 — 1/4" Mini, 150 PSI max, 38 CFM (no gauge)
- C-RS12 — 1/2" Standard, 250 PSI max, 104 CFM with gauge
- C-RS34 (this unit) — 3/4" Standard, 250 PSI max, 162 CFM with gauge
- C-RS10 — 1" Standard, 250 PSI max, 162 CFM with gauge
- RS114 — 1-1/4" Standard, 250 PSI max, 400 CFM (no gauge)
- RS112 — 1-1/2" Standard, 250 PSI max, 500 CFM (no gauge)
Match port size to your existing line size. A 3/4" regulator on a 1" line creates a restriction — size the regulator to your pipe.
When Does a Shop Need the C-RS34 vs. Stepping Up or Down?
- Use the C-RS34 if your main distribution line is 3/4" and you need pressure regulation with gauge visibility. Common in smaller shops, paint prep areas, or as a secondary regulator feeding specific equipment from a larger main.
- Step down to C-RS12 (1/2") if you're plumbing a branch line to a single air tool or drop — 1/2" is better suited to lower-flow individual station drops.
- Step up to C-RS10 (1") if your main line is 1" pipe. Don't run a 3/4" regulator on a 1" line; it will restrict flow.
- Step up to RS114 or RS112 for large-volume systems with high-CFM rotary screw compressors pushing through large-diameter mains.
Pairing With Other Castair 3/4" Components
For a complete FRL (filter-regulator-lubricator) air treatment train, Castair makes matching 3/4" NPT components:
- C-FS34 — 3/4" Particulate filter, 5-micron, 250 PSI max, 160 CFM
- C-CF34 — 3/4" Coalescing filter, 0.01-micron (requires upstream particulate prefilter)
- C-FRS34 — 3/4" Filter/Regulator combination with gauge
- C-LS34 — 3/4" Lubricator, 250 PSI max, 160 CFM
Technical Specifications
- Part Number: C-RS34
- Manufacturer: Castair (Spicer, Minnesota)
- Type: Standard Regulator with gauge
- Port Size: 3/4" NPT
- Maximum Inlet Pressure: 250 PSI
- Flow Capacity: 162 CFM
- Gauge: Included
Why Buy From Air Compressor Factory Direct?
We carry the full Castair line — regulators, filters, check valves, copper tubing, and replacement parts. When you call us, you're talking to someone who knows these systems. We can tell you which size regulator fits your line, whether you need a filter ahead of it, and what flow rating matches your compressor output.
- Free shipping on qualifying orders to the lower 48
- Free tech support — call before you buy if you're unsure which size fits
- Full manufacturer warranty on all Castair products
- Honest sizing advice — we'll tell you if a different size is a better fit
Call 866-217-0063 for quick answers and help!
