Castair Complete Air Filter Assembly and Element — 3/4" NPT Inlet, 12 CFM, Part 2140020A
This is the complete intake air filter assembly for Castair air compressors equipped with a 3/4-inch NPT inlet port. The assembly ships complete — housing and filter element — so replacement is a one-part order. At 12 CFM flow rating and a compact 4.0" OD x 3.0" overall height, this assembly is the correct direct-fit replacement for Castair compressor models with 3/4" intake connections.
If your compressor has a 1/2" NPT inlet, you want part 2140019A instead. The 3/4" inlet on this assembly (2140020A) is sized for slightly larger Castair pump models. Using the wrong inlet size restricts airflow or leaves a loose connection — both are problems worth avoiding.
Assembly Details
- Part Number: 2140020A
- Inlet Connection: 3/4" NPT (threaded)
- Flow Rating: 12 CFM
- Outer Diameter: 4.0"
- Overall Height: 3.0"
- Contents: Complete assembly — housing and filter element
- Manufacturer: Cast Air (Castair)
Why the Inlet Filter Matters
The intake air filter is the first line of defense for your compressor pump. Every cubic foot of air entering the cylinder carries ambient dust, debris, and moisture. The filter catches particulates before they reach piston rings and valve seats — components that wear fast when abrasive material gets past them.
- Protects piston rings and cylinder walls: Airborne particles act as abrasive between sliding surfaces inside the pump
- Protects valve seats: Grit on intake valves prevents complete seating, causes blow-by, reduces efficiency, and raises operating temperature
- Maintains designed airflow: A clean filter at the correct CFM rating keeps the pump breathing at capacity. A clogged filter restricts intake and the pump works harder for less output
2140019A vs. 2140020A — Choosing the Right Filter
Both assemblies share the same physical dimensions (4.0" OD x 3.0" height) and the same 12 CFM flow rating. The difference is the inlet connection size:
- Part 2140019A: 1/2" NPT inlet — fits smaller Castair pump models
- Part 2140020A (this part): 3/4" NPT inlet — fits larger Castair pump models
Check the inlet port on your compressor pump before ordering. The NPT thread size is typically stamped or cast near the port. If you cannot confirm the size, call us and we can cross-reference your compressor model.
What Is Included
- Filter housing (complete assembly)
- Filter element (installed, ready for use)
When to Replace
- Regular maintenance schedule: Inspect every 3-6 months depending on shop dust levels. Replace annually in average conditions, more frequently in dusty or high-use environments
- When the element is torn or collapsed: A damaged element provides no filtration — replace immediately
- When oil-soaked: Oil on the intake filter usually means pump blow-by — address the pump issue and install a fresh filter assembly
- After a pump rebuild or overhaul: Always start with a fresh filter element after any major pump service
Technical Specifications
- Part Number: 2140020A
- Manufacturer: Cast Air (Castair)
- Inlet Port: 3/4" NPT
- Flow Rating: 12 CFM
- Outer Diameter: 4.0"
- Overall Height: 3.0"
- Type: Complete assembly with element
Note: Manufacturer product page data was not available at time of writing. Specifications are derived from the product name and part number. Contact us to verify fit for your specific Castair compressor model before ordering.
Why Buy From Air Compressor Factory Direct?
We have specialized in air compressor parts and equipment since 2016. Castair replacement parts are a regular part of our inventory. If you are not sure whether 2140019A or 2140020A is the right filter for your compressor, call us — we can cross-reference your model and confirm the correct part before you order.
- Free shipping on qualifying orders
- Free tech support: Call 866-217-0063 to confirm the right part for your compressor
- Full manufacturer warranty
- Honest guidance: We stock both filter sizes and will point you to the correct one
Call 866-217-0063 for quick answers and help!
