Several types of water distribution systems are used within the houses.
1. In the direct systemall sanitary fittings, taps (faucets) and the hot water storage tank are connected directly to the water main. This is the normal system in use.
2. In the alternative system use of cold water storage tank for hot water supply is used. In this system all sanitary fittings and taps are connected directly to the cold water supply, but there is a cold water storage tank feeding the hot water storage tank.
3. In the Indirect System all the sanitary fittings, taps and the hot water storage tanks, with the exception of one cold water tap (usually the kitchen sink), are connected to a cold water storage tank.
· This is sited in the loft space to provide a good water pressure at the tap outlets.
· The level of water in the storage tank is controlled by a ball valve.
· This valve has a metal or plastic floating ball which is connected by a metal rod to a valve which is designed to allow water into the tank when the water in the tank falls below a pre-determined level.
· The main advantage of a storage tank is that it reduces the risk of back siphonage, which is the suction of dirty water back into the water main.
· This can occur if a negative pressure develops in the water main compared with the pressure at the sanitary fitting.