Pentair 355225-43 25 Micron Cartridge Filter 4.5x20 in

Product Description

The PENTAIR 355225-43 is a string-wound polypropylene cartridge filter rated at 25 microns for sediment reduction in residential and light commercial water filtration systems. Constructed with a polypropylene string-wound media, it traps dirt, rust, sand, and scale particles that degrade water quality and damage downstream equipment. The cartridge measures 20 inches in length with a 4.5-inch outside diameter, fitting standard Big Blue filter housings. It is rated for a maximum working pressure of 5 psi differential and handles water temperatures from 40 degrees F to 165 degrees F. Plumbers and water treatment technicians handle installation and periodic replacement of this cartridge.

This cartridge is suited for whole-house pre-filtration, point-of-entry sediment control, and commercial water conditioning systems where Big Blue housings are already installed. It is commonly positioned upstream of water softeners, carbon filters, or UV disinfection units to extend the service life of those downstream components. Typical applications include municipal water supplies with moderate to high sediment loads and well-water systems where particulate content varies seasonally.

Key Features

• 25-micron rating targets sediment including dirt, sand, rust, and scale
• String-wound polypropylene construction for chemical resistance and durability
• 20-inch length with 4.5-inch OD fits standard Big Blue filter housings
• Operating range of 40 degrees F to 165 degrees F suits a wide range of cold and hot water applications
• Maximum working pressure rating of 5 psi differential

Compatibility

Designed as an OEM-style replacement cartridge for Big Blue style filter housings accepting a 4.5-inch OD by 20-inch cartridge.

Installation Notes

Installation and cartridge replacement should be performed by a licensed plumber or qualified water treatment technician. Shut off the water supply and relieve line pressure before opening the filter housing. Follow local plumbing codes, including applicable IPC requirements, when integrating into a potable water system. Inspect housing O-rings during each cartridge change and replace them if cracked or deformed to prevent leaks on reassembly.