The flow of water to taps from a mains fed system is limited by the size of pipes and fittings that the water has to flow through. Where you have no restrictions, and large pipes, it is possible to get a large flow, even with a low pressure.
The problems start when pipes are smaller that desired, and act as a restriction. Old mains supply pipes into properties are typically 1/2 inch and even with a good pressure the water simply cannot flow through the pipe in great quantities.
To the user this is seen as a severe drop in flow rate from a tap when a second tap is opened simultaneously. There is not enough water coming in to do both, so it gets shared.
An accumulator is a simple fix. It is a water vessel containing a balloon of pressurised air. The mains water squashed the air as it fills the vessel, until the air pressure increases to match the mains supply pressure. Now, when a second tap opens up, the additional water required can be supplied from the vessel, at full mains pressure, without the restriction there is on the mains supply.
When all the water charge in the vessel has gone, the system returns to normal flow rates, so it is important to estimate the size you will need based upon how much water you may need before all taps shut and the vessel can recharge.
Installation could not get any easier, with one connection anywhere into the cold mains pipework. A non-return valve is also needed on the incoming mains to prevent the charge from disappearing back into the mains supply should the local pressure drop temporarily.
They are maintenance free and DIY installable, and with typical prices around the £200 mark, you are unlikely to find a cheaper way to improve your flow rates to taps.
DPS provide a complete range of vessels
from 30 to 1000 litres.