PRESSURE VESSELS

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.

Show in the centre is a typical pressure / expansion vessel.