Taps have pressure primarily due to the force applied to the water, pushing it out when you open the valve. This pressure can come from different sources, often relying on gravity or mechanical pumps.
Understanding Water Pressure at the Tap
Water pressure is essentially the force exerted by the water per unit area. When you open a tap, this pressure drives the water flow.
Pressure in Gravity-Fed Systems
In many traditional systems, especially in older homes or for specific outlets like some showers or ground floor taps, water pressure relies on gravity.
- How it Works: Water is stored in tanks located above the taps they supply. A common setup involves a cold water tank, often in the loft (attic), and sometimes a hot water cylinder on a lower floor or in an airing cupboard.
- The Role of Height: As highlighted in the provided reference, "The higher that the tank is from the endpoint (i.e. your shower or tap) the more pressure that you will see." This is because the weight of the water column above the tap pushes down, creating pressure. The greater the vertical distance, the heavier the column of water, and thus, the higher the pressure.
- System Components:
- Cold water storage tank (typically in the loft).
- Hot water cylinder (often lower down).
- Pipework connecting tanks to taps.
Pressure in Mains-Fed Systems
Many modern homes and taps (particularly kitchen sinks and combi boiler hot water) receive pressure directly from the mains water supply.
- How it Works: Water is delivered to your home under pressure by your water utility company. This pressure is generated by pumps and reservoirs within their network.
- Characteristics: Mains pressure is typically higher and more consistent than gravity pressure, although it can fluctuate based on local demand and infrastructure.
Pressure Boosting Systems
In some cases, where existing pressure (either gravity or mains) is too low, a water pump or pressure-boosting system may be installed to increase the flow and force of water to the taps.
- How it Works: An electric pump actively increases the pressure in the pipes, forcing water out of the tap with greater force.
How Height Creates Pressure (Gravity)
Let's delve a little deeper into the concept from the reference:
- Imagine a tall, narrow tube of water. The water at the bottom has to support the weight of all the water above it.
- This weight exerts a force downwards, which translates into pressure.
- The taller the tube (or the higher the water tank above the tap), the more weight is pressing down, and the greater the pressure at the bottom (or at the tap).
| System Type | Primary Pressure Source | Typical Locations | Pressure Level |
|---|---|---|---|
| Gravity-Fed | Height of water tank | Loft tank, Hot water cylinder | Lower to Moderate |
| Mains-Fed | Utility Company Pumps | Direct from street supply | Moderate to High |
| Pumped/Boosted | Electric Pump | Installed within home system | Can be High/Adjusted |
Understanding whether your taps are fed by a gravity system (where tank height matters) or mains pressure is key to diagnosing pressure issues.
