Franklin 4.5" Carbon Block Filter Cartridges – Big Blue Chlorine Reduction Water Filters (FWCB Series)

Franklin FWCB Carbon Block Filter Cartridges – 4.5" Diameter

The Franklin FWCB Series 4.5" Carbon Block Filter Cartridges are engineered for high-performance chlorine reduction, taste and odor improvement, and long service life in residential, commercial, and industrial water treatment systems. Manufactured using high-purity coconut shell activated carbon, these cartridges deliver exceptional filtration efficiency with minimal carbon fines, making them ideal for point-of-entry (POE), point-of-use (POU), and reverse osmosis (RO) pre- and post-filtration applications.

Available in 10" and 20" Big Blue (BB) formats and in 0.5 micron and 5 micron ratings, the FWCB cartridges offer industry-leading chlorine reduction capacities—up to 150,000 gallons at 4 GPM—with low pressure drop (ΔP), ensuring strong system performance. They are fully certified under NSF 42 and NSF 61, safe for potable water, and built to withstand operating conditions up to 150 psi and 120°F (50°C).

These cartridges are suitable for a wide range of industries including residential water treatment, commercial food service, and industrial process water.

Key Features for 4.5" Diameter Carbon Block Cartridges

Premium Coconut Shell Activated Carbon

• High chlorine, taste, and odor reduction capacity

• Minimal fines and high sediment-holding capability

Micron Rating Options

• 5 Micron (FWCB10B05 / FWCB20B05)

• 0.5 Micron (FWCB10BP5 / FWCB20BP5)

High Capacity Performance

• 4.5" x 10" (5 micron): >60,000 gallons @ 3 GPM

• 4.5" x 20" (5 micron): >120,000 gallons @ 4 GPM

• 4.5" x 10" (0.5 micron): >70,000 gallons @ 3 GPM

• 4.5" x 20" (0.5 micron): >150,000 gallons @ 4 GPM

Low Pressure Drop

• 3–5 psi ΔP at stated flow rates depending on micron rating

Temperature & Pressure Limits

• Operating temperature: 4–50°C (40–120°F)

• Maximum operating pressure: 150 psi (10 bar)

Certified & Safe

• NSF 42 – Chlorine, taste, odor reduction

• NSF 61 – Drinking water system components

Construction Materials

(From page 2 materials table)

• Filter media: 100% Coconut Shell Carbon

• End caps: Polypropylene

• Gasket: Natural Rubber

• Wrap/Netting: Polypropylene

Recommended Applications

• Potable & process water

• Food & beverage manufacturing

• Commercial filtration systems

• Industrial pre-filtration

• RO pre- and post-filter stages

• Residential POE/POU filtration

Frequently Asked Questions (FAQs)

What is the main difference between 0.5 micron and 5 micron versions?

• 0.5 micron: Finer filtration, higher chlorine reduction, slightly higher pressure drop

• 5 micron: Greater sediment handling capacity, lower pressure drop, longer flow durability

Are these cartridges suitable for drinking water?

Yes. They are NSF 42 and NSF 61 certified, meaning they meet standards for potable water filtration.

How long do these carbon block filters last?

Life expectancy depends on water quality, but capacity ranges as follows:

• 4.5"x10": 60,000–70,000 gallons

• 4.5"x20": 120,000–150,000 gallons

Can these filters remove chlorine taste and odor?

Yes. All FWCB cartridges are engineered for excellent chlorine reduction, with efficiency validated in laboratory testing.

What temperature can these filters operate at?

Operating range is 40–120°F (4–50°C).

What is the maximum operating pressure?

Maximum pressure is 150 PSI (10 bar).

What are the cartridges made from?

These carbon block cartridges are made from:

• 100% coconut shell activated carbon

• Polypropylene caps and netting

• Natural rubber gasket
  

Can these be used in RO systems?

Yes, they are ideal for pre-RO and post-RO filtration, helping protect membranes and improve final water quality.

Are Big Blue housings required?

Yes. These cartridges are sized for 4.5" OD Big Blue filter housings.

Do these filters remove microorganisms?

These carbon blocks are not rated for microbiological removal. Franklin recommends multiple barriers when water may contain pathogens.