Castair S-32DP-200 Complete Air Filter Assembly — 2” Inlet, 195 CFM, Silencer Type
The Castair S-32DP-200 is the heavy-duty intake filter for large industrial cast iron compressor pumps with a 2” NPT inlet, rated at 195 CFM. This is the top of the Castair air filter lineup — significantly larger body than the S-16D and S-20DP series, at 7.5” outer diameter and 7.5” overall height. If you are running a 20–30 HP cast iron pump with a 2” NPT inlet port, this is the filter that belongs on it. Anything smaller will restrict airflow and hurt pump performance at those displacement volumes.
The 32DP replacement element is specified for Castair S3, P3, S4, and P4 pump models — measuring 3-1/2” inner diameter, 5-3/4” outer diameter, and 4-7/8” height. These are Castair largest reciprocating pump configurations, used in their 20–30 HP industrial compressor lineup.
What the S-32DP-200 Does
- Large-volume filtration at 195 CFM: Sized to handle the full displacement of a 20–30 HP cast iron pump. At 195 CFM rated throughput, this assembly provides unrestricted airflow to the pump inlet even under heavy continuous-duty operation.
- Silencer-type noise attenuation: The large body and "S" designation mean this assembly reduces intake pulsation noise. On high-HP slow-RPM industrial pumps, intake noise can be substantial — this assembly addresses it at the source.
- Industrial-scale construction: The S-32DP body is proportionally larger than the S-16D or S-20DP series — heavier gauge, larger filter volume, higher flow capacity for the pump sizes it serves.
- Complete assembly: Ships with the 32DP element pre-installed and ready to thread onto the 2” NPT pump inlet.
Technical Specifications
- Part Number: S-32DP-200
- Manufacturer: Castair, Inc. (Spicer, MN)
- Inlet Connection: 2” NPT
- Outer Diameter: 7.5”
- Overall Height: 7.5”
- Flow Rating: 195 CFM
- Type: Silencer-type complete assembly
- Replacement Element: 32DP (ID 3-1/2”, OD 5-3/4”, Height 4-7/8”)
- Compatible Pumps: S3, P3, S4, P4 (per Castair cross-reference)
Compatible Applications
- Castair S3, P3, S4, and P4 cast iron pumps with 2” NPT inlets
- Castair 20–30 HP industrial compressor configurations
- Any reciprocating pump with a 2” NPT inlet displacing up to 195 CFM at operating pressure
Replacement Element: 32DP
- Element Part Number: 32DP (also referenced as F-32DP-200 in some Castair documentation)
- Inner Diameter: 3-1/2”
- Outer Diameter: 5-3/4”
- Height: 4-7/8”
- The 32DP element is significantly larger than the 20DP or 16D elements. Do not attempt to use a smaller element in this body.
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
- S-16D-100 — 1” inlet, 6.75” OD x 4.5” height, 30 CFM ($50.82)
- S-20DP-100/125/150 — 1”/1-1/4”/1-1/2” inlet, 6.75” OD x 7.0” height, 60 CFM ($71.61 each)
- S-32DP-200 — 2” inlet, 7.5” OD x 7.5” height, 195 CFM (this unit — $149.38)
When Does a Shop Need the S-32DP-200?
- Order the S-32DP-200 if your compressor pump has a 2” NPT inlet. There is no substitute for a pump this size — the S-20DP series cannot flow 195 CFM without restriction.
- If setting up a 20–30 HP Castair industrial compressor (I20xx, I25xx, I30xx series), this is the factory-spec intake filter for S3, P3, S4, or P4 pumps.
- The S-20DP-150 is not a substitute: It is physically smaller (6.75” OD vs 7.5” OD) and rated at one-third the CFM. Using it on a pump that needs the S-32DP-200 will restrict airflow and shorten pump life.
What’s in the Box
- 1x Castair S-32DP-200 complete air filter assembly (silencer type), 2” NPT inlet
- 1x 32DP filter element (pre-installed)
Why Buy From Air Compressor Factory Direct?
- Genuine Castair OEM component — specified for S3, P3, S4, P4 pumps by the manufacturer
- Free shipping on qualifying orders
- Free technical support at 866-217-0063 — if speccing a replacement for a large industrial pump and unsure which filter you need, call before ordering
- Full manufacturer warranty
- 32DP replacement elements stocked
Call 866-217-0063 for quick answers and help!
