washerless

Washerless is a term used in plumbing to describe faucet designs and related components that operate without a discrete washer as the primary means of sealing. In modern valve assemblies, "washerless" typically refers to faucets that use a cartridge or ceramic disc valve combined with O-rings and seat hardware integrated into the valve body rather than a flat rubber washer beneath the stem.

In a washerless faucet, turning the handle moves a valve cartridge or ceramic disc to open or close the flow path. The seal is formed by precision-machined surfaces on the cartridge or disc and by ancillary seals such as O-rings or gaskets. Because there is no separate washer that can become worn or deformed, these faucets generally have fewer failure points related to leaks, and maintenance often centers on replacing the cartridge or disc rather than rebuilding the valve stem.

Advantages of washerless designs include reduced drip risk from washer wear, smoother operation, and easier replacement of mechanical seals. Limitations include the potential for cartridge or disc wear over time, which can require more specific replacement parts, and often higher upfront cost compared with traditional washer-based faucets.

Washerless configurations are common in residential kitchens and bathrooms and have become standard in many new fixtures. Some older or budget fixtures still use washer-based valves, and compatibility concerns can arise when replacing components.

See also: Faucet, Cartridge valve, Ceramic disc valve, O-ring.