Low pressure systems require few valves or controls.
Typically, pressure limiting or pressure reducing valves will be used to control pressure in mains-supplied hot water systems or where high pressure may lead to problems such as burst pipes. Mains pressure systems require pressure limiting and pressure reducing valves to control water pressure and temperature. Existing buildings, and buildings that are not connected to mains water, may have low pressure systems or unequal pressure systems (with different pressures for hot and cold water supply).Īs an example of the difference in water usage, a low pressure hot water system shower flow may average about 7 litres per minute, while a mains pressure shower may average around 12–20 litres per minute. Typically, new buildings in areas with mains water supply will have mains pressure systems. If pressure is too high, this will lead to wastage of water, as well as high wear and tear on the system. If water pressure is too low, this will be inconvenient for building users – for example, because showers have poor water flow, and baths take a long time to fill. If the aim is to provide for building users’ needs while also using water efficiently, the right water pressure is crucial. Designing a water supply system involves getting all of these elements right so that clean water is delivered to the user at the appropriate rate and temperature. Some water supply systems also use storage tanks and pumps. A well-designed and installed system will also be durable, minimise noise from water flow and from problems such as water hammer, and support efficient use of water.Īll water supply systems use a combination of pipes (of different dimensions and materials), valves and outlets to deliver water to building users.