Figure 32  General 14 – Back Pressure Valves

This water distribution system is required to provide 0.075 m3/sec at four discharge points. 

The pressure at each discharge point must be a minimum of 1.5 barg. 

A BPV can be used to maintain pressure in the upper parts of a system. 

A BPV has been fitted in pipe P3 to maintain a required minimum pressure at the outlet from node N3, however the flow requirement of 0.075 m3/sec at node N5 cannot then be achieved without some additional head. A pump has been used to add head in order to increase the overall flow rate, so that 0.075 m3/sec can also be delivered at node N5.

The selected pump delivers about 0.3001 m3/sec and adds 5.929 m hd to the system, allowing a flow rate of 0.0751 m3/sec to exit at N5.