Replacement Seal Assembly, Black

The Fluidmaster B212 Replacement Seal restores optimal performance and reliability to Fluidmaster fill valves, preventing leaks and ensuring consistent tank refilling.

Engineered as an exact-fit replacement, the Fluidmaster B212 is designed for use with popular Fluidmaster fill valve models including 400A, PRO45, and 747. Constructed from high-quality rubber, this replacement seal provides a watertight closure, reducing noise and preventing constant tank running. Easy to install and built for long-lasting durability, the B212 is a quick and effective solution for toilet fill valve maintenance.

• Model number B212 identifies the Fluidmaster Replacement Seal designed for use with 400A, PRO45, and 747 Fill Valves.
• Provides a tight, leak-free seal that restores proper valve function and prevents water waste.
• Made from durable, chlorine- and chemical-resistant rubber to withstand harsh water conditions.
• Ideal for toilet fill valve repair and preventative maintenance in residential or commercial applications.

Technical Data & Specifications

• Manufacturer: Fluidmaster, Inc.
• Model Number: B212
• Product Type: Replacement Seal / Diaphragm for Fill Valve
• Compatible Models: Fluidmaster 400A, PRO45, and 747 Fill Valves
• Material: High-quality elastomer (rubber) compound
• Color: Black
• Seal Type: Circular diaphragm seal
• Function: Controls water shutoff and prevents leaks within fill valve assembly
• Dimensions: Standard size to match original Fluidmaster fill valve design
• Operating Pressure: Designed for typical residential water supply pressures up to 80 PSI
• Temperature Range: Suitable for cold to ambient water temperatures
• Installation: Snap-in replacement; no tools required
• Maintenance: Replace periodically or when water flow issues occur
• Resistance: Resistant to chlorine, hard water deposits, and municipal water treatment chemicals
• System Type: Gravity-fed toilet tank systems
• Compliance: Meets Fluidmaster OEM standards for performance and reliability
• Warranty: Fluidmaster 1-Year Limited Warranty

Features & Benefits

• Exact OEM replacement for Fluidmaster 400A, PRO45, and 747 fill valves.
• Eliminates leaks and restores efficient, quiet fill valve operation.
• Easy installation — no tools required; fits securely into existing valve housing.
• Made of durable, chemical-resistant rubber for long service life.
• Prevents continuous running toilets and water waste.
• Reliable performance under normal residential and light commercial water pressures.
• Ideal for routine maintenance or quick repair of Fluidmaster fill valve systems.
• Backed by Fluidmaster’s trusted reputation for quality and reliability.