Most faucet manufacturers offer a wide variety of faucet styles and faucet assemblies, but the basic function of all faucets is the same: to control the flow and temperature of water. The two types of faucet cartridges are the ceramic disk faucet and the cartridge faucet. As named, the ceramic disk faucet uses a cartridge with a ceramic disk assembly. This type of faucet cartridge is extremely durable and is found on high-end models. The cartridge faucet may be constructed of a durable brass or less reliable plastic cartridge.
Inside faucets, faucet cartridges operate the water pressure and temperature of water flowing through the faucet spout. Depending on the model, the faucet may have a single handle or a double handle. In a single-handle faucet, the cartridge assembly is nestled within the faucet stem, or body of the faucet. When the single-handle lever is lifted, the cartridge assembly opens to allow water flow. When the handle is moved to the right or left, hot or water flows through the spout accordingly.
For a double-handle faucet, a small cartridge sits within each handle independently of each other. When one of the faucet handles is turned, the cartridge assembly opens and allows water through the faucet stem. The cartridge faucet differs from the compression and ball faucet types in that the cartridge spins inside the stem to control water flow. A compression faucet acts like a threaded valve, twisting up and down inside the stem. The ball faucet, however, contains a small ball and cam assembly that pivots within the faucet stem.
The cartridge in a faucet consists of a small, cylindrical body with a thick, short, square-shaped stem protruding from the top. Faucet handles are designed to fit over the protruding stem. When the handle turns, the stem inside the cartridge turns as well, opening up the small channels from which water flows through the cartridge and into the faucet spout.
Different types of faucets use the faucet cartridge mechanism. Inexpensive kitchen and bathroom fixtures typically contain cheap plastic cartridges. More expensive faucet models utilize more expensive and much more durable assembly parts. Single lever faucets with brass faucet cartridges are common in kitchens and provide years of reliable service. Ceramic disk and brass faucet cartridges rarely fail; rather, the rubber o-rings or washers usually wear and cause faucet leaks. Manufacturers are aware of the need for maintenance and replacement, so they stock specific replacement parts for their particular faucet models.
Over time, the plastic stems snap away from the plastic cartridge body. Replacement is easy, however. The faucet handle is unscrewed from the body, the old cartridge is pried out from the stem, and a new one is easily installed in its place.