120320 backflow prevention

Sharing our Guidance

Backflow Prevention

Backflow Prevention

A Brief History of Backflow Prevention

• Recognizing the need for pure water• Double check valves• Major breakthrough in 1929• Safe Drinking Water Act

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Backflow Prevention

We the people, thecitizens, cry out for asolution to our backflowwoes.

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Backflow Prevention

The undesirable reversal of the flow of mixtures of water and other undesirable substance(s) from any source.

• Used water• Industrial fluids• Gases• Any substance other that potable water

What is Backflow?

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Backflow Prevention

1. Backpressure:The user system is at a higher pressure than the supply water system allowing undesirable substances to be “pushed” back into the potable water system.

• Booster pumps• Potable water systems connections to boilers• Interconnection with other piping at higher pressures• Higher elevations (high rise buildings)

Two Types of Backflow

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Backflow Prevention

2. Backsiphonage:When negative or reduced pressure exists in the supply piping allowing undesirable substances to be “drawn” into the potable water system.

• Undersized supply piping• Supply line breaks• Sudden upstream high demand

Two Types of Backflow (cont.)

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Backflow Prevention

Common Devices

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Backflow Prevention

Common Devices (cont.)

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Backflow Prevention

Common Devices (cont.)

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Backflow Prevention

Common Devices (cont.)

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Backflow PreventionCONCLUSION . . .

T H A N K Y O U .