Non-Revenue Water (NRW) savings - A new approach

By Matt Liang

Water networks always leak.

Reducing pressure during periods of low demand has long been a strategy to reduce water loss. Dual Set Pilot operated PRV with electronic controllers that set working high and low pressure by time of day is a quick and simple solution. They have reduced unaccounted for water losses significantly.

But dual set PRV has following limitations:

Only two set point. There are high demand, middle demand and low demand in a day. Even different in weekday and weekend. Dual set PRV is not flexible enough to optimize the pressure control in one day.

They can force control valves to operate beyond their design parameters. This results in cavitation damage and instability. Most standard PRV are designed to handle a pressure drop ratio of 3:1. If upstream pressure during the day is 9 bar the valve can safely reduce pressure to 3 bar without cavitation. However, the upstream pressure at night is normally higher than daytime. For example, t’s quite possible that the upstream pressure could increase to 12 bar at night because of lower friction losses. This leads to cavitation and consequent early failure.

To prevent such cases happen, a multiple set point PRV is a better choice to handle and optimize the real working condition. We called it Pressure Management Valve (PMV) type III. There are 12 time period VS pressure. Independent setting for each day. Battery operated with blue tooth and 4G communication.

User can easily optimize the network pressure by using PMV type III and divided a day into 12 time zone and pressure settings. Easily remote setting without going to site to commissioning the valve pilot.