A sink faucet works by controlling the flow and temperature of water through a valve system. When you turn the faucet handle, you're manipulating this valve, which allows water from the hot and cold water supply lines to mix (or not mix) before exiting the spout.
Basic Faucet Components and Operation
Here's a breakdown of how a typical sink faucet functions:
- Water Supply Lines: Hot and cold water are supplied to the faucet through separate pipes.
- Valve System: The core of the faucet's functionality lies in its valve system. There are different types of valves, including:
- Compression Valves: Older faucets often use compression valves. Turning the handle screws a stem down onto a rubber washer, compressing it to seal the water flow.
- Ball Valves: These valves, found in many single-handle faucets, use a slotted ball that rotates to control water flow and mixing.
- Ceramic Disc Valves: Modern faucets frequently use ceramic disc valves. Two ceramic discs with aligned holes control the water flow. These are very durable and leak-resistant.
- Cartridge Valves: Similar to ceramic disc valves, these use a cartridge with internal seals to control water flow.
- Spout: The spout is the curved or straight pipe through which the water exits the faucet.
- Handle(s): Handle(s) control the valve mechanism. Single-handle faucets control both flow and temperature, while double-handle faucets have separate controls for hot and cold water.
- Aerator: Many faucets have an aerator at the end of the spout. This mixes air into the water stream, creating a softer, less splashy flow and conserving water.
Operation Based on Faucet Type:
- Double-Handle Faucets: Turning the hot water handle opens the hot water valve, allowing hot water to flow to the spout. Turning the cold water handle opens the cold water valve, allowing cold water to flow to the spout. The user controls the water temperature by adjusting the position of each handle.
- Single-Handle Faucets: Moving the handle left or right controls the ratio of hot to cold water. Lifting the handle increases the water flow rate. Ball and ceramic disc valves are commonly used in single-handle faucets to efficiently control both temperature and volume. The video excerpt describes this: "When you turn the lever left and raise it the way for cold water is cut off but hot water can flow into the ball. When you raise the lever in the middle both cold." This implies the water flows into a mixing chamber (the "bulb" mentioned in the video excerpt) where the hot and cold water combine.
Summary
In essence, a sink faucet acts as a gatekeeper, regulating the flow and mixing of hot and cold water from your plumbing system, enabling you to achieve the desired water temperature and flow rate at the sink.
