It is recommended to use a pressure tank especially when a pump is connected to a toilet cistern. After a toilet is flushed it fills slowly and can cause a pump to cycle (switch on and off) until the cistern is full. Installation of a pressure tank will assist in eliminating this cycling.
Pressure Tanks are recommended to be installed in-line with pumps as they are:
Draw Off - 29 litres
This means that when a tap is turned, the water in the pressure cell is used first prior to the pump being turned on. This model will use 29 litres of water stored in the pressure cell prior to the turning on of the pump. Once this water is used, the pump will start. When the tap is turned off, the pump will continue to run to fill the pressure cell tank before the pump turns off.