Castair S-16D-075 Complete Air Filter Assembly — 3/4” Inlet, 20 CFM, Silencer Type
The Castair S-16D-075 is the factory intake air filter assembly for reciprocating compressor pumps with a 3/4” NPT inlet, rated at 20 CFM. This is a silencer-type complete assembly — it filters incoming air and attenuates intake pulsation noise in a single unit. The filter element is included and pre-installed. Body dimensions are 6.75” outer diameter and 4.5” overall height, the same housing as the S-16D-050, with a 3/4” NPT inlet thread.
Castair has manufactured cast iron compressor pumps and all associated components in Spicer, Minnesota since 1991. The S-16D-075 is a direct OEM part for their pump line. If your pump has a 3/4” NPT inlet and displaces up to 20 CFM, this is the correct filter assembly.
What the S-16D-075 Does
- Protects pump internals from contamination: Dust, metal particles, and shop debris entering an unfiltered pump intake accelerate piston ring and cylinder wall wear. This filter is the first line of defense for pump longevity.
- Silencer function: The "S" prefix indicates silencer-type construction. The filter body reduces the intake valve pulsation noise characteristic of reciprocating pumps.
- Complete assembly: Ships with the 16D element pre-installed. Ready to mount directly to the pump inlet port.
- Correctly sized for 20 CFM pumps: An undersized filter restricts inlet airflow and reduces pump output. This assembly is rated for 5–7.5 HP cast iron pumps with 3/4” inlets.
Technical Specifications
- Part Number: S-16D-075
- Manufacturer: Castair, Inc. (Spicer, MN)
- Inlet Connection: 3/4” NPT
- Outer Diameter: 6.75”
- Overall Height: 4.5”
- Flow Rating: 20 CFM
- Type: Silencer-type complete assembly with element
- Replacement Element: 16D (ID 3”, OD 4-3/8”, Height 2-1/8”) — fits A4 pump
Compatible Applications
- Castair A4-series cast iron pump with 3/4” NPT inlet
- Reciprocating compressor pumps with 3/4” NPT inlet connections displacing up to 20 CFM
- Typically associated with Castair 5–7.5 HP commercial and industrial compressor configurations
Replacement Element: 16D
- Element Part Number: 16D
- Inner Diameter: 3”
- Outer Diameter: 4-3/8”
- Height: 2-1/8”
- Per Castair published cross-reference, the 16D element fits both the S-16D-075 and S-16D-100 bodies and is specified for A4, VA80, C1, C2, and C3 pump models.
Available Configurations — Castair Air Filter Lineup
- S-16D-050 — 1/2” inlet, 6.75” OD x 4.5” height, 20 CFM
- S-16D-075 — 3/4” inlet, 6.75” OD x 4.5” height, 20 CFM (this unit)
- S-16D-100 — 1” inlet, 6.75” OD x 4.5” height, 30 CFM
- S-20DP-100 — 1” inlet, 6.75” OD x 7.0” height, 60 CFM
- S-20DP-125 — 1-1/4” inlet, 6.75” OD x 7.0” height, 60 CFM
- S-20DP-150 — 1-1/2” inlet, 6.75” OD x 7.0” height, 60 CFM
- S-32DP-200 — 2” inlet, 7.5” OD x 7.5” height, 195 CFM
When Does a Shop Need the S-16D-075 vs. Stepping Up or Down?
- Order the S-16D-075 if your compressor pump has a 3/4” NPT inlet and displaces up to 20 CFM. Common on 5–7.5 HP cast iron pumps.
- Step down to S-16D-050 if your pump inlet is 1/2” NPT. Same body size, smaller thread.
- Step up to S-16D-100 for 1” NPT inlets running up to 30 CFM — common on 7.5–10 HP pumps.
- Step up to S-20DP series for larger-displacement pumps (10–15 HP, up to 60 CFM). The 20DP body is taller with dual foam pre-filter construction.
What’s in the Box
- 1x Castair S-16D-075 air filter assembly (silencer type), 3/4” NPT inlet
- 1x 16D filter element (pre-installed)
Why Buy From Air Compressor Factory Direct?
- Genuine Castair OEM parts — correct fit, correct thread, correct element from the manufacturer
- Free shipping on qualifying orders
- Free tech support — call 866-217-0063 if you need help confirming which filter fits your specific pump
- Full manufacturer warranty
- Full Castair filter lineup in stock — we confirm the right part before you order
Call 866-217-0063 for quick answers and help!
