Page 333 - Water Loss Control

302 Cha pte r Ei g h tee n

Losses flex with pressure Pressure Economic level of real losses
management

Unavoidable
annual real
losses
Speed and quality Active
of repairs leakage control
Potentially
recoverable real
losses

Pipeline and
asset management
Current annual real losses selection,
installation,
maintenance,
renewal,
replacement

FIGURE 18.1 Pressure management component of real loss management. (Source: IWA Water
Loss Task Force/AWWA Water Loss Control Committee.)

This chapter is not designed to replace an all-encompassing valve manual. Cover-
ing every aspect of hydraulic control, valve manuals are available from most manufac-
turers and a good manual is available from the ISA. This is rather a very practical
“hands on” guide to using pressure management (pressure-reduction, level-control,
flow-control, and pressure-sustaining valves) as one of the many tools to reduce losses
and run water distributions systems in a more efficient manner.

18.2 Why Undertake Pressure Management Schemes? 1

18.2.1 Positive Reasons
Leakage Reduction
The reduction of leakage is a subject, which is on the minds of most water utility engi-
neers and managers throughout the world. In other chapters of the book we have dis-
cussed various types of leakage reduction programs of which pressure reduction is one.
As with all of the other techniques for reducing leakage, pressure management is just
one tool, which should be used where applicable in conjunction with other technologies
and methodologies.
Recent studies and research have shown that both leakage volume and new leakage
frequency is reduced greatly by the reduction and stabilization of pressure within a
distribution system. Obviously not all systems can tolerate pressure reduction and
indeed many systems suffer from lack of pressure, however there are still many, utilities
that are operating pressures in excess of those required, who would benefit greatly from