# Venturi doubt

ramonegumpert
Dear Physics experts,

I am trying to build a venturi tube.
I found some diagrams from the internet.
As we know, in the middle of the venturi tube, the pipe is narrower and this is where pressure is lowest and fluid passes through it the fastest. Imagine that this venturi tube is to pass pressured water through it and suck in some air to mix with the water as it flows out of the tube. So, there is a t-junction in the middle (low pressure region) where air can be sucked in. Lets call this the air inlet pipe. Now, when pressurised water passes through this tube, I am not able to understand why water will not escape through the air inlet pipe assuming the high and low water pressure are both higher than atmospheric presssure. So, what I mean is why doesn't the low water water flow into the air-inlet pipe IF this low pressure water is higher in pressure than the air pressure?

Hope you can clarify this doubt I have on Venturi effect.

Thanks and have a nice day.

Best regards
Ramone