Understanding leakage, flushing, and cavitation

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When working with a network model in WS pro

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it is important to be aware of leakage. Flushing and cavitation

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leakage refers to a specific type of unaccounted for water presumed lost

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to distribution losses such as from leaks in pipework or fittings,

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leakage can be estimated from flow data and

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located using acoustics such as acoustic data loggers.

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It is also possible to locate leakage from pressure monitoring.

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Given a sufficiently accurate network model.

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Understanding leakage is important to allocating demand in network models.

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Estimating leakage requires estimating or knowing the net flow within an area.

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The estimated legitimate night time usage per property and

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any known or predicted exceptional demand such as factories.

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Another important consideration of a network model is mains flushing.

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A common practice that involves discharging flow through a hydrant.

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Maine's flushing increases velocity and sheer stress

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in a pipe to dislodge sediment.

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This practice often requires networks to be partially isolated to

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endure unidirectional flow in the pipe to maximize velocity.

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Another concept to consider is cavitation,

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the rapid formation and collapse of air pockets in liquid.

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The collapse causes shockwaves that create a

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distinctive sound and can damage equipment.

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The cause of cavitation is a drop in pressure below vapor pressure when fluid

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cannot move fast enough through a mechanism typically through a pump or valve.

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Although it is not usually considered in network modeling.

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Understanding,

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cavitation is crucial during the investigation of control valves,

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pumps and even pipes in some conditions.