Pentair 355221-43 Cartridge Filter 100 Micron Big Blue

Product Description

The PENTAIR 355221-43 is a fibrillated polypropylene string-wound cartridge filter designed for use in Big Blue whole-house or commercial plumbing filtration systems. Rated at 100 microns, it targets sediment removal in cold and hot water supply lines. The cartridge measures 4-1/2 inches in outside diameter and 9-7/8 inches in length, fitting standard Big Blue filter housings. It handles supply pressures up to 8 psi and operating temperatures from 40 degrees F to 165 degrees F. Plumbers and water treatment technicians install this cartridge as part of a point-of-entry filtration setup to protect downstream fixtures and appliances from particulate contamination.

This filter is suited for residential and light commercial plumbing applications where sediment is the primary concern. Typical installations include whole-house pre-filtration ahead of water heaters, softeners, or reverse osmosis systems. The fibrillated polypropylene construction provides consistent depth filtration across the 100-micron rating, capturing fine particulates throughout the cartridge body rather than only at the surface. It is packaged and sold as a single unit.

Key Features

• 100-micron filtration rating targets sediment in supply lines
• Fibrillated polypropylene string-wound construction for depth filtration
• 4-1/2 inches OD fits standard Big Blue filter housings
• 9-7/8 inches length for high-capacity sediment loading
• Rated for temperatures from 40 degrees F to 165 degrees F
• Maximum operating pressure of 8 psi

Compatibility

Designed for use with Big Blue style filter housings accepting a 4-1/2 inch OD cartridge at 9-7/8 inches in length. Consult housing manufacturer specifications to confirm cartridge fitment before installation.

Installation Notes

Installation and replacement should be performed by a licensed plumber familiar with point-of-entry water filtration systems. Shut off the water supply and relieve system pressure before opening the filter housing. Follow local plumbing codes, including applicable IPC requirements, when integrating into potable water systems. Replace the cartridge on a schedule based on local water quality and observed pressure drop across the housing.