Castair Replacement Air Filter Element — Part 32DP, for F-32DP-200 Assembly
The Castair 32DP is the replacement filter element for the F-32DP-200 air filter assembly used on S3, P3, S4, and P4 compressor pumps. The element measures 3-1/2" inside diameter by 5-3/4" outside diameter. If the filter element on your S3, P3, S4, or P4 pump is dirty, torn, or collapsed, this is the correct OEM replacement. Running a compressor pump without a serviceable inlet filter is a fast way to destroy pump valves and bore surfaces — abrasive particles from unfiltered air cause accelerated wear that no amount of oil changes will compensate for.
Manufacturer page data was not available for this listing. Specifications are drawn from the product name and part number. Call 866-217-0063 to confirm fitment before ordering.
What This Filter Does
Function in the Compressor System
- Inlet filtration: The air filter element sits inside the F-32DP-200 filter assembly at the pump air inlet, catching dust, debris, and particulates before they enter the compression chamber
- Pump protection: Particulate contamination in the compression chamber accelerates piston ring and cylinder bore wear — a clean filter is the first line of protection for the pump
- Valve longevity: Reed valves and valve plates in reciprocating pumps are particularly sensitive to contamination — filter maintenance directly affects valve life
- Oil consumption: Worn piston rings from contaminated air cause increased oil consumption and oil carry-over into the compressed air stream
Filter Element Dimensions
- Inside Diameter (ID): 3-1/2 inches
- Outside Diameter (OD): 5-3/4 inches
- Assembly: Designed for the F-32DP-200 filter housing assembly
- Compatible Pumps: S3, P3, S4, P4 Cast Air pump models
Compatible Pump Models
- S3: Castair S-series pump, 3-cylinder configuration
- P3: Castair P-series pump, 3-cylinder configuration
- S4: Castair S-series pump, 4-cylinder configuration
- P4: Castair P-series pump, 4-cylinder configuration
If you are not certain which pump model your compressor uses, check the pump nameplate or the compressor service manual. Using the wrong filter element — either wrong ID/OD or wrong media type — can allow unfiltered air past the element seal.
When to Replace the Filter Element
Maintenance Schedule
- Under normal conditions: Inspect every 3 months; replace every 6-12 months depending on operating environment
- Dusty or shop environments: Inspect monthly; replace every 3-6 months — dusty shops fill filter elements faster than typical service intervals assume
- Signs of a dirty filter: Increased compressor run time to reach cut-out pressure, reduced air output, compressor runs hotter than normal
- Never wash and reuse paper filter elements: Once saturated, a paper element loses its filtration efficiency even after drying — replace, do not clean
What's in the Box
- 1x Castair 32DP replacement air filter element, 3-1/2" ID x 5-3/4" OD
- Note: The F-32DP-200 filter assembly housing is not included — this is the element only
Technical Specifications
- Part Number: 32DP
- Filter Assembly: F-32DP-200
- Compatible Pumps: S3, P3, S4, P4
- Inside Diameter: 3-1/2"
- Outside Diameter: 5-3/4"
- Type: Replacement filter element (element only, not the housing)
- Price: $42.35
Why Buy From OEM Diagnostic Tools?
- Specialist since 2016 in air compressor parts and maintenance supplies
- Free shipping on qualifying orders
- Free tech support at 866-217-0063 — confirm the 32DP element fits your specific pump and filter housing before ordering
- Full manufacturer warranty on Cast Air parts
- Honest guidance: We stock the full Cast Air filter line and can cross-reference your pump model to the correct element
Call 866-217-0063 for quick answers and help!
