PRESSURE VESSELS
A feature of many private water supply pumping systems is a pressure
vessel.
In a pressurised pumped system, a pump will increase the system
pressure until a pressure switch / controller sends a signal to activate
the pump. To avoid continuous switching when the call or water is low,
for example, when filling a kettle, a pressure vessel holds a store
of water that will provide a water flow at good pressure, without the
pump switching in..
A pressure vessel contains an internal butyl rubber membrane which has water
on one side and compressed air on the other. When the system pressure reaches
a pre set point the pump controller or pressure switch will send a signal to
the pump turning it off.
When properly sized, the vessel allows for high peak flows by allowing high peak flows above the normal operating parameters of the pump. The vessel in the centre of the picture to the right is a 200 litre vessel.
