The Flushmate B-108288-4PK duckbill valve, also known as an air inducer, is a precision-engineered replacement component designed for select Flushmate pressure-assisted toilet systems. Each pack contains four identical valves, ensuring users have spares for future maintenance.

Crafted from durable, flexible rubber or synthetic material, these valves are built to withstand repeated expansion and contraction cycles without cracking or losing shape. The duckbill design features a slit opening that opens under water pressure to allow air into the system and closes tightly to prevent leakage when pressure is released. This specific valve is compatible with Flushmate models 503, 503H, and 504 series, as well as the upper supply assembly BU100505. It directly replaces part number B-108288-4PK, offering an exact fit without modifications. The primary function of the duckbill valve is to regulate air induction during the toilet’s flush cycle. By admitting a controlled amount of air into the pressure vessel, it helps the flush maintain optimal force while reducing noise and splashing. A worn or clogged valve can lead to weak flushes, incomplete waste removal, or ghost flushing. Installing this component restores the system’s intended performance, delivering consistent, efficient flushing with each use. The valve works seamlessly with the pressure tank assembly, and its construction ensures long service life under normal household water conditions. From a material standpoint, the duckbill valve is made of a resilient elastomer that resists mineral buildup and chlorine degradation commonly found in municipal water supplies. Its smooth interior surface minimizes friction and prevents debris from obstructing the slit. The valve has no moving parts, relying solely on the pressure differential to open and close. This simple yet reliable mechanism reduces the risk of mechanical failure and makes installation straightforward for DIY homeowners or professional plumbers. The four-pack provides cost efficiency, allowing users to replace multiple valves across different fixtures or keep extras on hand for future replacements. In terms of performance, the duckbill valve ensures the pressure-assisted toilet operates at its rated efficiency. When functioning correctly, it contributes to a powerful yet quiet flush, reducing the likelihood of double flushing or clogs. The valve’s design also helps the toilet system conserve water by optimizing the air-to-water ratio inside the tank. Users of compatible Flushmate toilets will notice improved flush consistency and reduced maintenance intervals after swapping in this replacement part. No special tools are required for installation, and the valve simply pushes into the designated port on the upper supply assembly. This product offers great value for those seeking a reliable, affordable solution to maintain their Flushmate system. The four valves come packaged securely to avoid damage during shipping. Whether performing routine maintenance or troubleshooting a sluggish flush, this duckbill valve kit provides a straightforward way to restore performance. It is an ideal choice for households, rental properties, or commercial settings equipped with Flushmate pressure-assisted toilets from the specified series.