24 Classroom Training Module 2 DMA Construction and Commissioning  Zero Pressure Test ZPT is conducted following the Water Adequacy Test to ensure the tightness of isolations In principle, once all the isolation valves are closed including the inflow/s, pressure inside the DMA should drop to zero until no water comes out of the monitoring point/s The test is normally done during off-peak hours (1AM to 4AM), when demand is at its lowest and pressure is theoretically at its peak
{}