Transient Leakage Estimation in Pressure-Reducing Valves: A Comparative Assessment Using RWCM and EPS Models

Accurately estimating leakage volumes during valve operations remains a challenge in hydraulic modeling of water distribution networks (WDNs). Conventional simulation approaches, such as Extended Period Simulation (EPS), rely on quasi-steady-state assumptions, neglecting inertial effects during rapid valve maneuvers. This study proposes a novel methodology based on the Rigid Water Column Model (RWCM) to evaluate leakage behavior under transient conditions induced by valve operations.

A comparative analysis was conducted between the EPS and RWCM frameworks, examining multiple valve configurations under different operational scenarios. The models were tested in a real-world WDN, focusing on leakage volume predictions, instantaneous leakage rates, and non-revenue water (NRW) variations during both fast and gradual valve closures.

The results indicate that EPS consistently underestimates leakage volumes—by up to 50%—in short-duration events. In contrast, the RWCM accounts for transient pressure dynamics, capturing leakage peaks and oscillatory effects with higher precision. Specific valve designs exhibited significant deviations in the leakage volumes between models, with transient-sensitive simulations revealing substantially higher NRW fluctuations.

This study demonstrates the value of integrating inertial effects into hydraulic models for improved leakage assessment, particularly in dynamic operational scenarios. These insights can enhance digital twin applications and inform decision-making for network management. The findings emphasize the need for model selection aligned with system dynamics and valve-specific hydraulic responses.