A sink tap works by precisely controlling the flow of water from your plumbing system to your sink, using a simple yet effective internal mechanism to either permit or block water passage.
The Core Mechanism of a Compression Tap
The most common and foundational type, exemplified by the provided reference, is the compression tap. This design relies on a basic principle of sealing an opening to control water flow.
As water enters the tap from your supply line, it travels upwards through an internal passage, which can be thought of as a chamber or 'pillow' within the tap body. To stop this flow, the water is arrested at a specific point called a 'seat'. This crucial stoppage occurs because a washer, typically made of durable rubber or a similar pliable material, is compressed tightly against this seat. This washer is usually attached to a threaded rod, sometimes referred to as the 'Ed gear' or spindle, which moves up and down as you turn the tap handle.
- To open the tap: Turning the handle counter-clockwise raises the spindle. This lifts the washer off the seat, breaking the seal and allowing water to flow freely past the seat and out of the tap's spout.
- To close the tap: Turning the handle clockwise lowers the spindle. This presses the washer firmly back onto the seat, compressing it and creating a watertight seal that stops the flow of water.
Key Components and Their Roles
Understanding the various parts helps in grasping how a tap functions as a cohesive unit:
| Component | Function |
|---|---|
| Handle | The user interface; turned to activate the tap's internal mechanism. |
| Spindle/Stem | The threaded rod that moves up and down, connected to the handle. |
| Washer | A rubber or synthetic disc that creates a watertight seal against the seat. |
| Seat | A flat, smooth surface inside the tap where the washer presses to stop flow. |
| Tap Body | The main casing that houses all internal components and channels water. |
| Spout | The opening from which water exits the tap. |
How Water Flows Through a Tap: A Step-by-Step Guide
Here's a simplified sequence of events when you operate a typical compression tap:
- Water Enters: Pressurized water from your supply pipes enters the base of the tap body.
- Turning the Handle: You rotate the tap handle, which is directly connected to the spindle.
- Spindle Movement: The rotation of the handle causes the threaded spindle to either ascend (when opening) or descend (when closing) within the tap body.
- Washer Interaction:
- Opening: As the spindle rises, the attached washer lifts away from the seat, breaking the seal.
- Closing: As the spindle descends, the washer is pressed firmly against the seat, compressing to form a watertight barrier.
- Water Flow/Cessation:
- Open: With the washer lifted, water flows past the seat, up through the tap body, and out of the spout.
- Closed: With the washer pressed against the seat, the water flow is completely blocked.
Types of Sink Taps
While the compression tap is fundamental, modern plumbing offers several other types, each with its own mechanism:
- Compression Taps: As detailed, these rely on a rubber washer pressed against a seat. They are simple, durable, and easy to repair.
- Disc Taps (Ceramic Disc Taps): These taps use two ceramic discs (one fixed, one movable) with holes. When the holes align, water flows; when misaligned, the flow stops. They offer excellent durability and drip-free performance.
- Ball Taps: Often found in single-lever designs, these use a rotating ball with slots to control water flow and temperature. They are prone to wear on the ball seals.
- Cartridge Taps: These taps use a replaceable cartridge that contains the mixing and flow-control mechanism, often featuring ceramic discs or rubber seals. They are common in modern single-lever mixers.
Maintaining Your Tap
The most common issue with compression taps is a leaky faucet, often due to a worn-out washer. Over time, the rubber can harden, crack, or degrade, preventing it from forming a perfect seal against the seat. Fortunately, replacing a washer is a straightforward DIY task that can quickly resolve drips and leaks, extending the life of your tap. Regular cleaning and occasional inspection can help maintain optimal performance.
