| Term/abbreviation | Description |
| Advanced Pressure Management | Varying the PRV outlet pressure in response to demand and other factors in order to minimise the average zone pressure (AZP). Sometimes known as pressure modulation. |
| APV | Advanced pilot valve |
| AZP | Average Zone Point, the point in the DMA which sees the average zone pressure
|
| Basic Pressure Management | Installation of PRV with a fixed outlet pressure |
| Controller | Electronic controller used to control the PRV output pressure |
| Critical Point | The point in the DMA which sees the lowest pressure |
| DMA | District meter area |
| FAVAD | Fixed and Variable Area Discharge. Formula used to calculate effect of pressure on leakage |
| IP68 | Watertight enclosure down to a specified depth (i2O equipment designed and tested to 4m) |
| IWA | International Water Association |
| P1 | Pressure at PRV inlet |
| P2 | Pressure at PRV outlet |
| P3 | Pressure at Critical Point |
| P3 Sensor | Sensor measuring and transmitting pressure at Critical Point |
| P3ref | Minimum pressure at Critical Point specified by the water company. Normally between 15m and 20m |
| P4 | Pressure at the AZP
|
P4 Sensor
| Sensor measuring and transmitting pressure at the AZP
|
| PRV | Pressure reducing valve |
| Safe Mode | P2 remains at a pre-determined, safe value |
| Watchdog | Independent circuit monitoring the correct operation of the system. |
| Water Loss Task Force | Set up by the IWA to develop and promote best practice in water loss management |