Is vacuum breaker required?

[rutherford703]

Good morning everyone,

Please refer to attached drawing for your information.

In the piping arrangement, we have enough pressure to push the water through the piping. The piping discharge will be submerged in the pond water. My question is "Is the vacuum breaker at the highest point necessary for the HDPE piping?" Any thoughts are appreciated.

 

[TD2K]

What is the ability of the HDPE piping to resist vacuum? If the flow stops (say your upstream control valve goes fully closed), the pressure at the highest point in the system is going to be under a partial vacuum, either 6.8 or 7.8 m below atmospheric (can't tell if your 1 m at the water is referring to the water level or the amount below the water surface the pipe exit is located.

 

[rutherford703]

This is a modified query. In the previous query, thread378-321976, bimr clearly indicated that the vacuum breaker is not necessary. I would like to ask why.

 

[BigInch]

No breaker is required. If you have enough pressure to move the water to the top of the gooseneck (about 70 kPag), any water that makes it to the top will run out. No worries about that. You only need a vacuum breaker, if you are depending on maintaining a siphon to get the water over the top or avoid a vacuum in the pipe. I would imagine that the pipe is strong enough to resist a 1 atm external pressure, but you should verify that.

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