Pentair 155321-43 Water Softener Cartridge Filter 20in

Product Description

The PENTAIR 155321-43 is a water softener cartridge filter designed for residential and light commercial plumbing filtration systems. Measuring 20 inches in length with a 4.5-inch outside diameter, this cartridge is constructed from FDA-grade standard softener resin, making it suitable for potable water applications. It supports a maximum flow rate of 2.00 GPM and is rated for water temperatures up to 100 degrees F. Licensed plumbers and water treatment technicians install this cartridge in whole-house softener housings as part of ion exchange or pre-filtration setups. The FDA-grade resin material confirms it meets food-grade safety standards for drinking water contact.

This cartridge filter is used in point-of-entry water treatment systems where softening or resin-based filtration is required. Typical applications include residential whole-house installations and light commercial settings that rely on a standard large-format filter housing. The 20-inch length fits standard big-blue or equivalent cartridge housings that accommodate 4.5-inch OD cartridges. It is sized for systems requiring moderate flow capacity at lower operating temperatures, making it a practical fit for softener pre-filter or standalone resin filtration stages in plumbing systems.

Key Features

• FDA-grade standard softener resin construction for potable water compliance
• 20-inch cartridge length fits standard large-format filter housings
• 4.5-inch outside diameter for compatibility with big-blue style housings
• Maximum flow rate of 2.00 GPM for controlled filtration performance
• Rated up to 100 degrees F maximum working temperature

Compatibility

Designed as an OEM-style replacement cartridge for standard large-format plumbing filter housings that accept 4.5-inch OD, 20-inch cartridges in residential and light commercial water treatment systems.

Installation Notes

Installation should be performed by a licensed plumber or qualified water treatment technician. 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. Do not exceed the rated maximum flow rate or temperature during operation.