SpiroPure SP-BP-420-5 5 Micron #4 Glazed Polypropylene Felt Bag - Case

In this review of the SpiroPure SP-BP-420-5 bag filter the bottom line is clear: this is a practical choice for technicians and facilities that need a robust, chemical-resistant particulate filter for demanding liquids. The reviewer found the 5 micron glazed polypropylene felt media particularly useful where corrosive fluids, oils, or organic solvents are present, and the case quantity of 40 makes it well suited to continuous industrial use. For anyone running standard-sized housings that accept a #4 bag, this product delivers consistent filtration with a high dirt-holding capacity.

Key Features

• Glazed polypropylene felt: provides chemical resistance and durability when filtering acids, alkalis, oils, and organic solvents.
• 5 micron nominal rating: captures fine particulates while maintaining reasonable flow for industrial process applications.
• #4 size compatibility: fits standard-sized filter housings that accept a 4 in x 15 in bag, simplifying replacements.
• High dirt-holding capacity: reduces change-out frequency in critical applications, lowering downtime for routine operations.
• Case of 40: supplies enough replacement bags for multiple maintenance cycles or continuous production runs.
• 30-day money back guarantee: gives a short-term safety net for buyers testing fit and performance in their systems.

Who It's For

The SpiroPure SP-BP-420-5 is aimed at maintenance teams, process engineers, and labs that handle corrosive or solvent-bearing fluids and need a dependable disposable bag option. It is especially relevant for facilities that use standard #4 housings and require a steady stock of filters to keep operations running without frequent interruptions.

Those who should look elsewhere include users needing absolute micron ratings for critical laboratory separations or those with nonstandard housings that do not accept a #4 bag. Also, if your application requires reusable metal or cartridge filters for waste reduction, a disposable felt bag may not be the ideal long-term choice.

Pros & Cons

Pros

• Good chemical compatibility from the glazed polypropylene felt for use with acids, alkalis, and solvents.
• High dirt-holding capacity helps extend service life between changes in demanding process conditions.
• Case pack of 40 supplies plenty of replacements for ongoing maintenance schedules.
• Available nominal micron rating of 5 strikes a balance between particle retention and flow.

Cons

• Nominal, not absolute, micron rating may be unsuitable for applications needing guaranteed particle cutoff.
• Disposable design increases consumable waste compared with reusable alternatives.

Specifications

Brand	SpiroPure
Model	SP-BP-420-5
Media	Glazed polypropylene felt
Micron rating	5 micron nominal
Size	#4 (4 in x 15 in)
Quantity	Case of 40
Application	Corrosive fluids, oils, organic solvents

Our Verdict

For industrial users who need a reliable, chemically tolerant disposable bag filter that fits standard #4 housings, the SpiroPure SP-BP-420-5 is a solid value: the glazed PP felt and high dirt-holding capacity reduce change-outs and handle corrosive fluids well. It is not the right pick where absolute micron control or reusable filters are required, but for routine process filtration it balances cost and performance effectively.

Frequently Asked Questions

Does this bag fit standard #4 housings?
Yes, the SP-BP-420-5 is offered in the #4 size (4 in x 15 in) to fit standard-sized filter housings that accept that bag dimension.

Is the 5 micron rating absolute?
The listed 5 micron is a nominal rating, so it indicates typical performance but is not an absolute particle cutoff for certification-grade separations.

Can it handle acidic or solvent-based fluids?
Yes, the glazed polypropylene felt media is designed for use with corrosive fluids including acids, alkalis, oils, and organic solvents.