[meschaefer]

http://www.dursostandpipes.com/

[Psycho graphic]

I've seen that site, it does'nt explain how or why they work though.

As I see it the submerged end obviously does'nt allow for air to enter, therefore it won't allow it into the tubing, but won't the vent allow it to draw air, thus creating noise?

I almost get the idea, I'm just missing one part I think and it's driving me crazy as I usualy can understand things like this.

If you have a perfect balance of return and drain that does'nt allow any air to enter the tubing, why would it make any difference as to how big the vent is?

[steveo32]

Meschaefer, my durso runs super quite at first then every 3mins or so it rushes water down. Is that the "flushing" sound your talking about ?> if so I can correct it by making my hole bigger ?

[meschaefer]

Quote: Originally Posted by steveo32 Meschaefer, my durso runs super quite at first then every 3mins or so it rushes water down. Is that the "flushing" sound your talking about ?> if so I can correct it by making my hole bigger ?

The durso stand pipe page attriubutes this to back pressure, where the overflow empties in the sump. That is the first place to look. If you do not have any back pressure, then you can try increasing the size of the hole.

[meschaefer]

Quote: Originally Posted by Psycho graphic I've seen that site, it does'nt explain how or why they work though. As I see it the submerged end obviously does'nt allow for air to enter, therefore it won't allow it into the tubing, but won't the vent allow it to draw air, thus creating noise? I almost get the idea, I'm just missing one part I think and it's driving me crazy as I usualy can understand things like this. If you have a perfect balance of return and drain that does'nt allow any air to enter the tubing, why would it make any difference as to how big the vent is?

In theory, but you are never going to have a perfect balance of return and drain, where the exact amount of water you are pumping into the overflow matches exactly the size of the reutrn line. And if you do, then don't worry about durso stand pipes.

When the water is rushing down the pipe, it creates suction. That suction will pull water out of the return, until the mouth of the pipe is exposed and then it will suck air. It will suck air until the suction brakes, and then water will fill the pipe again. As the pipe fills with water the pressure builds, wich will eventually create more suction. By regulating the hole, you are trying to feed enough air into the system to avoid the suction. If the hole is to small, you create suction, if the hole is to big, you end up pulling to much air into the system wich is also noisy.

[Psycho graphic]

Gotcha, and thanks.

I still don't see how this is any better than adding a valve to slightly slow the flow down so there is no air entering, but that is niether here nor there.

As you said it could clog, but I've never had this happen and have used this idea on a few tanks that have run for years without any problems.

Thanks for the explanation.