Castair Replacement Air Filter Element — 6" OD
This is a genuine Cast Air replacement filter element for Castair industrial air compressors. Keeping the intake air clean is one of the cheapest forms of pump insurance you can buy. A clogged or missing filter element sends abrasive particulates into the cylinder bores, valve seats, and piston rings — the parts that cost the most to replace. Swap this element on schedule and your pump lasts significantly longer. Skip it and you are paying for it in early wear.
What This Filter Does
- Protects the pump intake: Captures airborne dust, grit, and particulates before they enter the compression chamber.
- Maintains airflow efficiency: A clean element lets the pump breathe freely at rated capacity. A saturated element starves the intake and increases amp draw.
- Extends valve life: Contaminated air is the primary cause of premature valve fouling in cast iron compressor pumps.
- OEM-fit replacement: Designed specifically for Castair industrial compressor filter housings — drop-in fit, no modification required.
Filter Element Specifications
- Part Number: 6 (Castair catalog reference)
- Outer Diameter: 6" nominal
- Element Type: Dry pleated filter element
- Application: Castair industrial compressor filter housings requiring a 6" OD element
- Construction: Pleated filter media with end caps for positive seal in housing
A Note on Manufacturer Specifications
Castair's published filter element catalog lists elements ranging from the compact Part #04 (OD 2-3/8") through larger units like the Part #32DP (OD 5-3/4"). The 6" OD specification for this particular element falls outside the standard flat Solberg sizes published on their major components page at the time of this writing. If you need to confirm exact dimensions — inner diameter, height, and media type — before ordering, call us at 866-217-0063. We can cross-reference your specific filter housing model and confirm the correct fit.
Cast Air Filter Element Lineup Context
Cast Air sources filter elements in several configurations to cover their compressor lineup:
- Flat Solberg elements (Parts #04, #06, #10): Smaller-diameter flat elements for compact single-stage pump intakes.
- Deep cartridge elements (Parts #8D, #10D, #12D, #16D): Cylindrical elements that fit specific pump models including the DD20, PK20/50, PK60/65, A2, A4, VA80, C1, C2, and C3 pumps.
- Pre-filter elements (Parts #16DP, #20DP, #32DP): Deep cartridge elements with an outer foam pre-filter that traps coarse particles before they reach the main pleated media — used on larger industrial models including the C4U and the S3/P3/S4/P4 series.
- This element (Part #6): 6" OD element for larger filter housings. Contact us to confirm the correct application for your pump model.
When to Replace Your Filter Element
- Every 500–1,000 operating hours under normal shop conditions — more frequently in dusty environments (woodworking, concrete work, sandblasting areas).
- When you see visible discoloration or when the element is clogged enough to restrict airflow noticeably.
- Anytime the pump is opened for valve or piston service — install a fresh element while you have it apart.
- If the housing has been running without an element — check valve seats and cylinder walls before returning to service.
Why Filter Maintenance Matters on Cast Iron Pumps
Cast Air builds their pumps from cast iron for longevity. Cast iron cylinders are rebuildable, but they are not indestructible. The slow-speed design (most Cast Air pumps run 600–1,000 RPM at the pump) keeps heat and wear low, but that advantage disappears fast if the intake air carries grit. A $20–$40 filter element changed on schedule is the least expensive maintenance item on the entire compressor. It is also the one most shops skip.
If you are running a Cast Air compressor in a dusty environment — a woodshop, a grinding bay, a fabrication floor — consider moving to a pre-filter element (the DP series) or adding an inlet pre-filter wrap. The extra layer of protection pays for itself in extended element life and reduced pump wear.
Compatibility
This element is designed for Castair compressor filter housings requiring a 6" OD element. If you are unsure whether this is the correct part for your specific pump model and filter housing, call 866-217-0063. Give us your pump model number and we will confirm the right element before you order.
Why Buy From Air Compressor Factory Direct?
- Cast Air specialist: We stock genuine Cast Air parts and know the lineup. When specs are unclear, we can cross-reference your housing and confirm the right part.
- Free shipping on qualifying orders.
- Free technical support: Call 866-217-0063. Our team can help you identify the correct element for your pump model and filter housing.
- Genuine Cast Air parts: OEM elements, not aftermarket substitutes. Correct dimensions and media specification for your housing.
- No guessing: If you give us your pump model, we will verify fit before you order.
Call 866-217-0063 for quick answers and help!
