Help with drain vents

[oldsaint]

Not sure if that's what they're called. I think Matt has them on his 225. It's the T or Wye fitting with a pipe extending out the top, installed on the drain pipe going into the sump.
What is the concept behind that? Does the pipe coming out of the top need to be a certin length? Does someone have a link that might help me understand a little more?

 

[Tampa Aquarium Service]

Go here http://www.dursostandpipes.com/

Basically they work the same as the plumbing in your house. The vent allows air and water to smoothly flow through the plumbing. Try to empty a gallon milk jug filled with water by just flipping it over, it will empty slowly with a glug,glug,glug sound. Punch a hole in the bottom to let air enter and the water will flow much faster and smoothly. same principal.

 

[oldsaint]

I guess I didn't relate the two. I can see now it's the same.
Thanks

 

[robthorn]

drill a smaller hole than you think you need at first and then run the pump and upsize the vent hole until it stops siphoning. if you drill it too big you may end up hearing the water falling in the pipe. too small will siphon and break causing a loud gurgle for lack of a real word. or real spelling which ever I messed up.

 

[luminary]

The silencers I have dropping into my sump are the exact same principle. I just needed to quite things down both in my overflow and where the water dumps out (3000 gph is a lot of loud moving water!).