The Castair 3/8" Muffler (M38) reduces exhaust noise from the unloader or intake on a compressed air system. On a reciprocating piston compressor, the intake valve pulls in ambient air every downstroke — without a muffler on the intake filter or the unloader port, that cycling creates a sharp, repetitive noise that adds up to significant sound levels in a shop. The M38 threads onto a 3/8" NPT port and attenuates that intake or exhaust pulse noise without restricting airflow.
What This Muffler Does
Air compressor mufflers work by routing the exhaust or intake pulse through a sintered or baffled element that breaks up the pressure wave and converts it to heat and friction rather than sound. The M38 handles 3/8" ported applications — typically the compressor intake or the unloader valve exhaust. Unloader valves vent compressed air when the compressor cycles off-load; without a muffler, that venting is loud. The M38 quiets that exhaust pulse. On intake applications, it reduces the snorkel noise of air being drawn through the valve on each piston downstroke.
Key Features
- 3/8" NPT Thread: Standard thread size — fits directly into 3/8" NPT ports on compressor intakes and unloaders
- Noise Attenuation: Reduces high-frequency exhaust and intake pulse noise without meaningfully restricting airflow
- Cast Air Part: Sourced from Cast Air's compressor accessories line for correct fit with their equipment
- Compact Size: Threads in close to the port — doesn't add significant clearance requirements
Technical Specifications
- Part Number: M38
- Thread Size: 3/8" NPT
- Component Type: Exhaust / Intake Muffler
- Manufacturer: Cast Air
- Price: $13.09
Note: Manufacturer's product page was unavailable at time of writing. Confirm thread size and application compatibility before ordering.
Typical Applications
- Compressor intake filter port — quiets air draw noise on each piston downstroke
- Unloader valve exhaust port — reduces the sharp venting noise when the compressor cycles off
- Pressure switch exhaust vent on reciprocating compressors
- Any 3/8" NPT exhaust port in an air system where noise reduction is needed
- Replacement for worn or clogged mufflers on existing Cast Air compressors
Why Buy From OEM Diagnostic Tools?
We stock Cast Air accessories and replacement parts including mufflers, fittings, and maintenance components. We've been serving shops and industrial facilities since 2016. At $13.09, the M38 is a straightforward fix for a compressor that's gotten louder than it should be. Free shipping on qualifying orders. Call us if you need help confirming the right muffler for your application.
Call 866-217-0063 for quick answers and help!
