SpiroPure SP-BP-420-1 1 Micron #4 Bag Filter - High Dirt Capacity

In this review the SpiroPure SP-BP-420-1 (1 micron, #4) liquid bag filter is evaluated for industrial filtration tasks where chemical compatibility and high dirt-holding capacity matter. The reviewer found it most valuable for process lines handling corrosive fluids, oils, and solvent streams because the glazed polypropylene felt media balances fine particle capture with long service life. For facilities that run standard-sized housings and need consistent 1 micron nominal filtration in a bulk supply, this case of 40 offers convenience and predictable performance.

Key Features

• Glazed polypropylene felt media: Provides chemical resistance suitable for acids, alkalis, oils, and many organic solvents while maintaining structural integrity during flow.
• High dirt-holding capacity: Extends run time between changeouts on heavy-loading or abrasive service, reducing maintenance interruptions.
• #4 size compatibility: Designed to fit standard #4 filter housings (4 in x 15 in) for straightforward replacement in existing systems.
• Nominal 1 micron rating: Captures fine particulate for critical applications where sub-10 micron removal improves downstream processes or protects equipment.
• Case quantity of 40: Suits facilities that prefer stocking multiple bag changes and simplifies inventory management for routine maintenance.
• 30-day money back guarantee: Offers a short-term return option for buyers who need to validate fit and performance in their specific process.

Who It's For

The SP-BP-420-1 is best for industrial operators, chemical processors, and maintenance teams running filter housings that accept #4 bags and require a nominal 1 micron level of filtration. It fits plants treating corrosive fluids, oil-based streams, or solvent-bearing liquids where polypropylene compatibility and high dirt capacity are priorities.

It is less appropriate for users who need absolute-rated filters, very high temperature polymer-resistant media beyond PP compatibility, or nonstandard bag sizes. Laboratories or specialty processes demanding certified absolute efficiency should consider other media types designed for precise particle-count guarantees.

Pros & Cons

Pros

• Good chemical compatibility with common acids, alkalis, oils, and solvents thanks to glazed PP felt.
• High dirt-holding capacity reduces frequency of bag changes in heavy-loading services.
• Standard #4 dimensions (4 in x 15 in) ensure easy swap-in for existing housings.
• Bulk case of 40 aids operations with frequent replacements or multiple filter stations.

Cons

• Nominal rather than absolute 1 micron rating means particle retention varies with load and may not meet strict absolute-efficiency requirements.
• Polypropylene media has temperature and solvent limits compared with specialty high-temperature or PTFE materials.

Specifications

Brand	SpiroPure
Model	SP-BP-420-1
Micron rating	Nominal 1 micron
Size	#4 (4 in x 15 in)
Media	Glazed polypropylene felt
Quantity	Case of 40
Applications	Corrosive fluids, oils, alkalis, organic solvents

Our Verdict

The SpiroPure SP-BP-420-1 #4 bag filter is a practical choice for industrial users who need a reliable, chemically compatible 1 micron nominal filter with strong dirt-holding capacity. It represents good value for plants that run standard housings and want to minimize downtime with bulk supplies, while buyers needing absolute-rated filtration or extreme temperature resistance should evaluate alternative media.

Frequently Asked Questions

Will this bag fit my existing #4 housing?
The bag is manufactured to standard #4 dimensions (4 in x 15 in) and is intended to fit standard-sized housings; verify your housing accepts #4 bags before ordering.

Is the 1 micron rating absolute?
This product is a nominal 1 micron filter, so retention varies with particle shape and loading and is not the same as an absolute-rated cartridge.

Can it handle corrosive liquids?
Yes, the glazed polypropylene felt media is suitable for many acids, alkalis, oils, and organic solvents, but check compatibility for specific chemicals and temperatures.