Failure Analysis of a Water Supply Pumping Pipeline System

Abstract

This paper describes the most important results of a theoretical, experimental and in situ investigation developed in connection with a water supply pumping pipeline failure. This incident occurred after power failure of the pumping system that caused the burst of a prestressed concrete cylinder pipe (PCCP). Subsequently, numerous hydraulic transient simulations for different scenarios and various air pockets combinations were carried out in order to fully validate the diagnostic. As a result, it was determined that small air pocket volumes located along the pipeline profile were recognized as the direct cause of the PCCP rupture. Further, a detail survey of the pipeline was performed using a combination of non-destructive technologies in order to determine if immediate intervention was required to replace PCC pipes. In addition, a hydraulic model was employed to analyze the behavior of air pockets located at high points of the pipeline.

Approaches to Failure Risk Analysis of the Water Distribution Network with Regard to the Safety of Consumers

“…The following trends of safety research can be distinguished, as risk analysis, where assessment models form the basis for building decision models; and risk engineering, where the assessment of design options in terms of safety is the basis for choosing the best solution [13][14][15]. A water supply system's (WSS) loss of safety may result directly from the failure of its individual subsystems or elements, such as water intakes, pumping stations, the water distribution network (WDN) or its utilities [16][17][18][19][20]; from the failure of other technical systems (e.g., sewerage, energy, water structures) [21]; from undesirable extreme natural phenomena like floods and droughts; or from the incidental pollution of water sources [22,23]. Risk analysis of the WSS should be preceded by analysis of the reliability of all subsystems in terms of interruptions to water supply [24,25], as well as failure to meet quality requirements for health posing threats to consumers of water [26].…”

Emptying Operation of Water Supply Networks

“…Researchers have analyzed the consequences of transient events in pipelines in the following situations: during the filling process [3,4,8,9], at pumping stations [10,11], analyzing the propagation of air pockets [12], in valve closures [11], and by using protection devices [13,14]. The authors have developed a mathematical model to analyze the emptying process using experimental facilities [5,15], which was validated for a single pipe at the Universitat Politècnica de València, Spain [15] and for a pipeline of irregular profile at the University of Lisbon, Portugal [5].…”

Experimental and Numerical Analysis of Hydraulic Transients in the Presence of Air Valve

“…One of the few articles on numerical modelling of air valves are [4] and [5]. [4] handles the flow as one-dimensional with the idea that the entrapped air can be modelled using boundary conditions and the fully filled up pipeline can be solved using the standard method of characteristics.…”

“…[4] handles the flow as one-dimensional with the idea that the entrapped air can be modelled using boundary conditions and the fully filled up pipeline can be solved using the standard method of characteristics. Unfortunately, [5] does not give enough detail about the modelling aspects, but both articles have promising results.…”